oneTesla - a small single-board DRSSTC
Dr. ISOTOP, Mon Jun 11 2012, 03:52AM12/28/2012:
Support our Kickstarter Campaign!
Our webstore (in progress) can be found here
*Coil specs*
*~220KHz Fres
*2.5x10" secondary, 36 AWG with 2x8" topload
*Peak current: 350A
*Max spark length (ground strikes): 23"
*400VDC doubled variac feeding a half-bridge of FGH60N60SMD's
*14AWG primary, 6 turns on 3.5" former, 68 nF 3KV CDE940 series tank cap
12/09/2012:
Better video footage, with a spun toroid:
For y'all people who are building this from eBay boards, I have a bit here about things you should and shouldn't do.
7/15/2012 UPDATES:
This project has grown a lot since it was first conceived. Performance is now up to about 2', from a 10" secondary, using FGH60N60SMD IGBT's.
pics:
There's a short run of professionally fabbed boards for sale here to help fund further development. Kramnik and I also have more complete accessories, a kit, and a polyphonic interrupter in the works.
Critical specs of the new coil:
*~220KHz Fres
*10" secondary, 36 AWG
*Peak current: 350A
*Max spark length (ground strikes): 23"
*400VDC doubled variac feeding a half-bridge of FGH60N60SMD's
*12AWG primary, 68 nF 3KV CDE940 series tank cap
If you want to assemble your own from an eBay board get the Eagle files here.
-----------------------OLD INFO BELOW--------------------------------------------- -
Inspired by EVR's microBrute, I decided to route a DRSSTC onto a 4"x6" board.
The result:
Half the credit for this project goes to Daniel Kramnik, who built the coil in the video above using his revision of my design (which includes an optical interrupter).
The driver:
Low-power (~50W) sparks:
Critical coil specs:
Driver: half-bridge of FGH60N60SMD IGBT's
Primary: 4.5 turns of 14 AWG on a 3.5" PVC former
Secondary: 2.5x7", 36 AWG with a 2x7" topload. Resonant frequency is ~320KHz
Tank cap: CDE940C30S68K-F, 0.068 uF@3KV
The video is running at 250A with 30uS on time and 340V bus voltage.
Power figures:
4"@30W, 5uS on
6"@80W, 20uS on
10"@140W, 30uS on
(all numbers at 200 bps)
Blog post about it here:
Board file for the (old) version of the coil:
Digikey BOM for everything except the transistors:
Re: oneTesla - a small single-board DRSSTC
Thomas W, Mon Jun 11 2012, 05:50AM
Nice!
that is a really good idea, and design :D
Thomas W, Mon Jun 11 2012, 05:50AM
Nice!
that is a really good idea, and design :D
Re: oneTesla - a small single-board DRSSTC
lightlinked, Tue Jun 12 2012, 06:06AM
thats pretty awesome. how long of a streamer can you get in free air? what does the interrupter look like? is over current protection not needed in little coils?
lightlinked, Tue Jun 12 2012, 06:06AM
thats pretty awesome. how long of a streamer can you get in free air? what does the interrupter look like? is over current protection not needed in little coils?
Re: oneTesla - a small single-board DRSSTC
Dr. ISOTOP, Tue Jun 12 2012, 03:05PM
I can get 6-7" in free air; note that the entire coil floats, so this may be limiting my streamer performance.
The interrupter is microcontroller with optocoupled output.
I've yet to need OCD on this coil. The bridge seems to hold up fine during ground strikes.
Dr. ISOTOP, Tue Jun 12 2012, 03:05PM
lightlinked wrote ...
thats pretty awesome. how long of a streamer can you get in free air? what does the interrupter look like? is over current protection not needed in little coils?
thats pretty awesome. how long of a streamer can you get in free air? what does the interrupter look like? is over current protection not needed in little coils?
I can get 6-7" in free air; note that the entire coil floats, so this may be limiting my streamer performance.
The interrupter is microcontroller with optocoupled output.
I've yet to need OCD on this coil. The bridge seems to hold up fine during ground strikes.
Re: oneTesla - a small single-board DRSSTC
Josh Campbell, Tue Jun 12 2012, 07:09PM
Ha, great design. Good choice of song too, I like how the music's pitch affected the resonance and thus the output. Do you input unmodified (audible range) music or do you modify it to fall in a specific tonal range?
Josh Campbell, Tue Jun 12 2012, 07:09PM
Ha, great design. Good choice of song too, I like how the music's pitch affected the resonance and thus the output. Do you input unmodified (audible range) music or do you modify it to fall in a specific tonal range?
Re: oneTesla - a small single-board DRSSTC
Dr. ISOTOP, Tue Jun 12 2012, 07:14PM
The pitch affects the break rate, hence total power throughput and spark length.
I believe this is with unmodified music; the interrupter is Daniel Kramnik's design, so we shall wait for him to answer.
Dr. ISOTOP, Tue Jun 12 2012, 07:14PM
2bytes wrote ...
Ha, great design. Good choice of song too, I like how the music's pitch affected the resonance and thus the output. Do you input unmodified (audible range) music or do you modify it to fall in a specific tonal range?
Ha, great design. Good choice of song too, I like how the music's pitch affected the resonance and thus the output. Do you input unmodified (audible range) music or do you modify it to fall in a specific tonal range?
The pitch affects the break rate, hence total power throughput and spark length.
I believe this is with unmodified music; the interrupter is Daniel Kramnik's design, so we shall wait for him to answer.
Re: oneTesla - a small single-board DRSSTC
Ben Solon, Tue Jun 12 2012, 08:34PM
if you ground it you not only will get longer streamers, but the audio will stop crackling too. that's because the crackling is caused by the streamer having trouble breaking out. notice how you get perfect audio quality when you get "ground" strikes.
but on another note, very nice! i saw this somewhere a couple days ago, but good to see you have finalized it.
Ben Solon, Tue Jun 12 2012, 08:34PM
if you ground it you not only will get longer streamers, but the audio will stop crackling too. that's because the crackling is caused by the streamer having trouble breaking out. notice how you get perfect audio quality when you get "ground" strikes.
but on another note, very nice! i saw this somewhere a couple days ago, but good to see you have finalized it.
Re: oneTesla - a small single-board DRSSTC
Steve Ward, Sun Jun 17 2012, 06:55PM
Excellent IGBT choice
. I say this because i use that part for some other projects of mine and im very happy with them.
Have you reached a point of part failure? or have you simply limited the on-time and current to be "safe"? I suppose your single MMC cap can only take so much as well.
Maybe also consider using 2 separate heatsinks so that you can directly mount the IGBTs and avoid thermal resistance of an insulator. At least i'd look at that for maximizing the performance of those parts.
Very nice work, either way.
Steve Ward, Sun Jun 17 2012, 06:55PM
Excellent IGBT choice
. I say this because i use that part for some other projects of mine and im very happy with them.Have you reached a point of part failure? or have you simply limited the on-time and current to be "safe"? I suppose your single MMC cap can only take so much as well.
Maybe also consider using 2 separate heatsinks so that you can directly mount the IGBTs and avoid thermal resistance of an insulator. At least i'd look at that for maximizing the performance of those parts.
Very nice work, either way.
Re: oneTesla - a small single-board DRSSTC
Dr. ISOTOP, Sun Jun 17 2012, 10:22PM
I've yet to reach IGBT failure on the 60N60's; on the old bridge (FGH40N60SMDF) it would silently die at about 300A. Been meaning to push the coil to the point of destruction, but I'm out of 60N60's for now
a few transistors gave their lives due to human error.
Here's a new video with streamers; tying the secondary base to earth ground worked wonders. I also added a low-pass filter (R and C in parallel to ground) on the feedback pin on the 7414, which got rid of the static-ish noise in the first video.
Three coils are better than one, right?
Dr. ISOTOP, Sun Jun 17 2012, 10:22PM
Steve Ward wrote ...
Excellent IGBT choice. I say this because i use that part for some other projects of mine and im very happy with them.
Have you reached a point of part failure? or have you simply limited the on-time and current to be "safe"? I suppose your single MMC cap can only take so much as well.
Maybe also consider using 2 separate heatsinks so that you can directly mount the IGBTs and avoid thermal resistance of an insulator. At least i'd look at that for maximizing the performance of those parts.
Very nice work, either way.
Excellent IGBT choice
. I say this because i use that part for some other projects of mine and im very happy with them.Have you reached a point of part failure? or have you simply limited the on-time and current to be "safe"? I suppose your single MMC cap can only take so much as well.
Maybe also consider using 2 separate heatsinks so that you can directly mount the IGBTs and avoid thermal resistance of an insulator. At least i'd look at that for maximizing the performance of those parts.
Very nice work, either way.
I've yet to reach IGBT failure on the 60N60's; on the old bridge (FGH40N60SMDF) it would silently die at about 300A. Been meaning to push the coil to the point of destruction, but I'm out of 60N60's for now
a few transistors gave their lives due to human error.Here's a new video with streamers; tying the secondary base to earth ground worked wonders. I also added a low-pass filter (R and C in parallel to ground) on the feedback pin on the 7414, which got rid of the static-ish noise in the first video.
Three coils are better than one, right?
Re: oneTesla - a small single-board DRSSTC
Daniel Kramnik, Fri Jul 13 2012, 02:26AM
Update!
Bwang sent out a double-sided version of the board - all noise issues are long gone, and the performance is even better with longer on-times and looser coupling.
Specs. are ~2 feet spark length with 300 - 350A primary current at 400Vbus and a 2.5" x 10" secondary.
Daniel Kramnik, Fri Jul 13 2012, 02:26AM
Update!
Bwang sent out a double-sided version of the board - all noise issues are long gone, and the performance is even better with longer on-times and looser coupling.
Specs. are ~2 feet spark length with 300 - 350A primary current at 400Vbus and a 2.5" x 10" secondary.
Re: oneTesla - a small single-board DRSSTC
lightlinked, Sat Jul 14 2012, 10:53PM
would stuffing the secondary with caps like in steve's qcw tesla gun improve mini coil performance?
will a batch of boards be sold?
lightlinked, Sat Jul 14 2012, 10:53PM
would stuffing the secondary with caps like in steve's qcw tesla gun improve mini coil performance?
will a batch of boards be sold?
Re: oneTesla - a small single-board DRSSTC
kwinchee, Sun Jul 15 2012, 03:01AM
This is sweet! would also be interested in a board if you sell a batch :)
kwinchee, Sun Jul 15 2012, 03:01AM
This is sweet! would also be interested in a board if you sell a batch :)
Re: oneTesla - a small single-board DRSSTC
Daniel Kramnik, Sun Jul 15 2012, 07:40AM
Boards are on sale now! (link)
I'll admit they are a bit pricey, but you get free fast shipping, and profits go towards improving oneTesla =)
Daniel Kramnik, Sun Jul 15 2012, 07:40AM
Boards are on sale now! (link)
I'll admit they are a bit pricey, but you get free fast shipping, and profits go towards improving oneTesla =)
Re: oneTesla - a small single-board DRSSTC
Dr. ISOTOP, Sun Jul 15 2012, 06:10PM
Probably not by much. Steve's QCW is special in that it has an exceedingly low topload voltage, meaning the secondary MMC is feasible and the secondary does not flash over.
Dr. ISOTOP, Sun Jul 15 2012, 06:10PM
lightlinked wrote ...
would stuffing the secondary with caps like in steve's qcw tesla gun improve mini coil performance?
will a batch of boards be sold?
would stuffing the secondary with caps like in steve's qcw tesla gun improve mini coil performance?
will a batch of boards be sold?
Probably not by much. Steve's QCW is special in that it has an exceedingly low topload voltage, meaning the secondary MMC is feasible and the secondary does not flash over.
Re: oneTesla - a small single-board DRSSTC
Killa-X, Sun Jul 15 2012, 10:01PM
I'll buy a board off you from your eBay, nothing like helping someone out with a project...I got a s all coil, 3.5 x 12 at 150khz, let's see what it can do!!
*sighs* I guess i bought two :P
Killa-X, Sun Jul 15 2012, 10:01PM
I'll buy a board off you from your eBay, nothing like helping someone out with a project...I got a s all coil, 3.5 x 12 at 150khz, let's see what it can do!!
*sighs* I guess i bought two :P
Re: oneTesla - a small single-board DRSSTC
Dr. ISOTOP, Mon Jul 16 2012, 12:23PM
Killa-X pointed out to me it would be nice to have a full list of materials.
This one is nearly complete (when combined with the list on my blog):
1 UCC37321
1 UCC37322
1 74HC14
1 74HC74
3 16V electrolytics, I think 8mm spacing, preferably 1000uF
10 1uF ceramics
1 100 nF capacitor
1 330 pF capacitor
1 100k resistor
1 10k resistor
1 600ohm resistor
1 200ohm resistor
2 6.8ohm resistor
2 1N4148 diodes
2 MUR460 diodes (or some other 4A axial-package rectifier of at least 250V)
1 7815 regulator
1 7805 regulator
1 IF-D95 optical receiver
1 PJ-037B power jack (from Digikey)
It'll need a 19V wall adapter (such as a laptop adapter) to run. You'll also need to throw together an optocoupled interrupter of some sort (555/Arduino/whatever), but that's not terribly hard.
Note that at this point, the project isn't really production-ready, so if you buy a board, be ready to do some troubleshooting on your own. Kramnik and I will gladly help, but please do post your questions here (as opposed to PM's/e-mails) for all to see.
Also, Eagle is essential right now for assembly; the schematic really helps when putting things together/finding component values. There's a raw capture of the board attached for those who don't use Eagle.
Dr. ISOTOP, Mon Jul 16 2012, 12:23PM
Killa-X pointed out to me it would be nice to have a full list of materials.
This one is nearly complete (when combined with the list on my blog):
1 UCC37321
1 UCC37322
1 74HC14
1 74HC74
3 16V electrolytics, I think 8mm spacing, preferably 1000uF
10 1uF ceramics
1 100 nF capacitor
1 330 pF capacitor
1 100k resistor
1 10k resistor
1 600ohm resistor
1 200ohm resistor
2 6.8ohm resistor
2 1N4148 diodes
2 MUR460 diodes (or some other 4A axial-package rectifier of at least 250V)
1 7815 regulator
1 7805 regulator
1 IF-D95 optical receiver
1 PJ-037B power jack (from Digikey)
It'll need a 19V wall adapter (such as a laptop adapter) to run. You'll also need to throw together an optocoupled interrupter of some sort (555/Arduino/whatever), but that's not terribly hard.
Note that at this point, the project isn't really production-ready, so if you buy a board, be ready to do some troubleshooting on your own. Kramnik and I will gladly help, but please do post your questions here (as opposed to PM's/e-mails) for all to see.
Also, Eagle is essential right now for assembly; the schematic really helps when putting things together/finding component values. There's a raw capture of the board attached for those who don't use Eagle.
Re: oneTesla - a small single-board DRSSTC
HB, Sat Jul 21 2012, 08:40AM
I like this i'm planning to buy a couple at the beginning of this next month been wanting to play around with a DR and get the hang of things before i build something more complicated. This seems just what i need thanks alot.
HB, Sat Jul 21 2012, 08:40AM
I like this i'm planning to buy a couple at the beginning of this next month been wanting to play around with a DR and get the hang of things before i build something more complicated. This seems just what i need thanks alot.
Re: oneTesla - a small single-board DRSSTC
Mr Pink, Sun Jul 22 2012, 10:15AM
Could you ship a board to Sweden?
If so I would be interested in buying one :)
The project looks great, I like it when things are kept as simple as possible but still are able to perform.
Mr Pink, Sun Jul 22 2012, 10:15AM
Could you ship a board to Sweden?
If so I would be interested in buying one :)
The project looks great, I like it when things are kept as simple as possible but still are able to perform.
Re: oneTesla - a small single-board DRSSTC
Dr. ISOTOP, Sun Jul 22 2012, 10:06PM
You should PM Kramnik about that, since he's the one doing the shipping right now.
And thanks! This board was originally designed to be easy-to-etch, hence its minimalism.
Dr. ISOTOP, Sun Jul 22 2012, 10:06PM
Mr Pink wrote ...
Could you ship a board to Sweden?
If so I would be interested in buying one :)
The project looks great, I like it when things are kept as simple as possible but still are able to perform.
Could you ship a board to Sweden?
If so I would be interested in buying one :)
The project looks great, I like it when things are kept as simple as possible but still are able to perform.
You should PM Kramnik about that, since he's the one doing the shipping right now.
And thanks! This board was originally designed to be easy-to-etch, hence its minimalism.
Re: oneTesla - a small single-board DRSSTC
Killa-X, Thu Jul 26 2012, 12:51AM
I did a LOW power test, 100A, with IRFP260s (the 60N60 igbts are in the mail) seems to work well :) about 5" sparks.
Killa-X, Thu Jul 26 2012, 12:51AM
I did a LOW power test, 100A, with IRFP260s (the 60N60 igbts are in the mail) seems to work well :) about 5" sparks.
Re: oneTesla - a small single-board DRSSTC
nixie, Sun Jul 29 2012, 03:06PM
Hi There,
I bought one of the boards. And received the known items through Mouser/Digikey.
A few questions on materials and assembly. These may be common, and might help others wanting to build it.
(a) Heat Sink; Who is the supplier/Part number?
(b) GDT Core; a spec, or recommended supplier/part number?
(c) GDT windings; how many turns? I'm guessing 20 perhaps?
Thanks, Jeff
nixie, Sun Jul 29 2012, 03:06PM
Hi There,
I bought one of the boards. And received the known items through Mouser/Digikey.
A few questions on materials and assembly. These may be common, and might help others wanting to build it.
(a) Heat Sink; Who is the supplier/Part number?
(b) GDT Core; a spec, or recommended supplier/part number?
(c) GDT windings; how many turns? I'm guessing 20 perhaps?
Thanks, Jeff
Re: oneTesla - a small single-board DRSSTC
Dr. ISOTOP, Sun Jul 29 2012, 09:20PM
1) Mine are currently pulled from ATX power supplies; I'm still seeking a supplier that will do small quantities.
2) I used a Sanlin SL5 core about an inch in diameter
3) 15-20 turns seems about right.
Dr. ISOTOP, Sun Jul 29 2012, 09:20PM
nixie wrote ...
Hi There,
I bought one of the boards. And received the known items through Mouser/Digikey.
A few questions on materials and assembly. These may be common, and might help others wanting to build it.
(a) Heat Sink; Who is the supplier/Part number?
(b) GDT Core; a spec, or recommended supplier/part number?
(c) GDT windings; how many turns? I'm guessing 20 perhaps?
Thanks, Jeff
Hi There,
I bought one of the boards. And received the known items through Mouser/Digikey.
A few questions on materials and assembly. These may be common, and might help others wanting to build it.
(a) Heat Sink; Who is the supplier/Part number?
(b) GDT Core; a spec, or recommended supplier/part number?
(c) GDT windings; how many turns? I'm guessing 20 perhaps?
Thanks, Jeff
1) Mine are currently pulled from ATX power supplies; I'm still seeking a supplier that will do small quantities.
2) I used a Sanlin SL5 core about an inch in diameter
3) 15-20 turns seems about right.
Re: oneTesla - a small single-board DRSSTC
Ben Solon, Sun Jul 29 2012, 11:55PM
Heatsink USA will sell relatively cheap heatsink by the inch^2, but I don't know if they do price breaks. They will also drill and tap for you(probably extra).
Really, any ferrite with a high permeability and good transfer at the desired frequency will work. Then just calculate the # of turns=(V*T)/(B*Ae).
I just may have to make/buy one of these myself after my big drsstc is done! Good work bwang and Kramnik, this is an interesting project you've got going here.
Ben Solon, Sun Jul 29 2012, 11:55PM
Dr. ISOTOP wrote ...
1) Mine are currently pulled from ATX power supplies; I'm still seeking a supplier that will do small quantities.
2) I used a Sanlin SL5 core about an inch in diameter
3) 15-20 turns seems about right.
nixie wrote ...
Hi There,
I bought one of the boards. And received the known items through Mouser/Digikey.
A few questions on materials and assembly. These may be common, and might help others wanting to build it.
(a) Heat Sink; Who is the supplier/Part number?
(b) GDT Core; a spec, or recommended supplier/part number?
(c) GDT windings; how many turns? I'm guessing 20 perhaps?
Thanks, Jeff
Hi There,
I bought one of the boards. And received the known items through Mouser/Digikey.
A few questions on materials and assembly. These may be common, and might help others wanting to build it.
(a) Heat Sink; Who is the supplier/Part number?
(b) GDT Core; a spec, or recommended supplier/part number?
(c) GDT windings; how many turns? I'm guessing 20 perhaps?
Thanks, Jeff
1) Mine are currently pulled from ATX power supplies; I'm still seeking a supplier that will do small quantities.
2) I used a Sanlin SL5 core about an inch in diameter
3) 15-20 turns seems about right.
Heatsink USA will sell relatively cheap heatsink by the inch^2, but I don't know if they do price breaks. They will also drill and tap for you(probably extra).
Really, any ferrite with a high permeability and good transfer at the desired frequency will work. Then just calculate the # of turns=(V*T)/(B*Ae).
I just may have to make/buy one of these myself after my big drsstc is done! Good work bwang and Kramnik, this is an interesting project you've got going here.
Re: oneTesla - a small single-board DRSSTC
Dr. ISOTOP, Mon Jul 30 2012, 03:06AM
It needs to be the right shape of extrusion (for board-mounting).
Really, the cheapest way might just be getting surplus Dell PSU's off eBay and gutting them
Dr. ISOTOP, Mon Jul 30 2012, 03:06AM
ben123324 wrote ...
Heatsink USA will sell relatively cheap heatsink by the inch^2, but I don't know if they do price breaks. They will also drill and tap for you(probably extra).
Heatsink USA will sell relatively cheap heatsink by the inch^2, but I don't know if they do price breaks. They will also drill and tap for you(probably extra).
It needs to be the right shape of extrusion (for board-mounting).
Really, the cheapest way might just be getting surplus Dell PSU's off eBay and gutting them
Re: oneTesla - a small single-board DRSSTC
Killa-X, Mon Jul 30 2012, 05:01AM
I got my heatsinks off ebay, had to really hack them up to fit.
I use the ferrites electronic goldmine USE to sell.
I'm using 8 turns, which is my typical DRSSTC setup.
Seems to work great, may do a 120V test with IGBTs today, get more sparks you know? :D
Killa-X, Mon Jul 30 2012, 05:01AM
I got my heatsinks off ebay, had to really hack them up to fit.
I use the ferrites electronic goldmine USE to sell.
I'm using 8 turns, which is my typical DRSSTC setup.
Seems to work great, may do a 120V test with IGBTs today, get more sparks you know? :D
Re: oneTesla - a small single-board DRSSTC
Dr. ISOTOP, Tue Jul 31 2012, 10:36PM
So Killa-X told me via PM that the IGBT's died at 300A doing burst mode operation. Kramnik also killed a bridge doing music with really long pulsewidths, so I guess the conclusion to be drawn here is that the coil doesn't like super-high duty cycles.
Dr. ISOTOP, Tue Jul 31 2012, 10:36PM
So Killa-X told me via PM that the IGBT's died at 300A doing burst mode operation. Kramnik also killed a bridge doing music with really long pulsewidths, so I guess the conclusion to be drawn here is that the coil doesn't like super-high duty cycles.
Re: oneTesla - a small single-board DRSSTC
Ben Solon, Tue Jul 31 2012, 10:54PM
Raise be impedence of the system a couple times. I would like to see the results of that. It might not increase spark length or primary current, but the longer on-times might make it a bit more user friendly for people who buy one without the knowledge of exactly how they work.
What exactly have the limits been? 300A by Kramnik, has anyone else blown a bridge and measured the conditions? The irg4pc50Ud might be a decent upgrade...
Ben Solon, Tue Jul 31 2012, 10:54PM
Raise be impedence of the system a couple times. I would like to see the results of that. It might not increase spark length or primary current, but the longer on-times might make it a bit more user friendly for people who buy one without the knowledge of exactly how they work.
What exactly have the limits been? 300A by Kramnik, has anyone else blown a bridge and measured the conditions? The irg4pc50Ud might be a decent upgrade...
Re: oneTesla - a small single-board DRSSTC
Killa-X, Tue Jul 31 2012, 11:08PM
I had to been running 50 primary current cycles...quiet a bit heh...plus i was burst-mode.
Once i replace the bridge later on i will leave everything the same and attempt to count the cycles..and measure the on vs off time, of when my coil went pop..
Most DRSSTC bridges have a snubber capacitor on them, is it not required on yours for some reason..?
not to mention i had 1 flash over before the video, i lifted the coil up by an inch, fixed the issues.
Killa-X, Tue Jul 31 2012, 11:08PM
I had to been running 50 primary current cycles...quiet a bit heh...plus i was burst-mode.
Once i replace the bridge later on i will leave everything the same and attempt to count the cycles..and measure the on vs off time, of when my coil went pop..
Most DRSSTC bridges have a snubber capacitor on them, is it not required on yours for some reason..?
not to mention i had 1 flash over before the video, i lifted the coil up by an inch, fixed the issues.
Re: oneTesla - a small single-board DRSSTC
Dr. ISOTOP, Tue Jul 31 2012, 11:16PM
IMO high-impedance primaries are actually less user-friendly - they require long on-times and run the transistors hotter.
I haven't tried the IRG4PC50UD yet...they seem roughly equivalent to the 60N60's I've been using and have a higher thermal impedance, plus they are a bit slower.
Wow, nice work. 50 cycles is a lot...that's a couple hundred microseconds at your resonant frequency right? If you were variac'ing the bridge while keeping pulsewidths and such constant, have you tried holding the bridge at a constant voltage and raising pulsewidth until you find performance satisfactory?
My original excuse for not using a snubber was that i didn't have the board space for one (back when the board was etched on to 4x6" PCB stock from eBay). The current design uses a super-low-inductance laminated bus, so I haven't really found a need for a film cap yet. A film cap will most likely improve performance a bit - you can try soldering one directly to the capacitor terminals if you want.
As an FYI for everyone who has bought a board so far: the bleeders are meant to be soldered directly to the buscap terminals on the bottom of the board! Use bleeders!
Dr. ISOTOP, Tue Jul 31 2012, 11:16PM
ben123324 wrote ...
Raise be impedence of the system a couple times. I would like to see the results of that. It might not increase spark length or primary current, but the longer on-times might make it a bit more user friendly for people who buy one without the knowledge of exactly how they work.
What exactly have the limits been? 300A by Kramnik, has anyone else blown a bridge and measured the conditions? The irg4pc50Ud might be a decent upgrade...
Raise be impedence of the system a couple times. I would like to see the results of that. It might not increase spark length or primary current, but the longer on-times might make it a bit more user friendly for people who buy one without the knowledge of exactly how they work.
What exactly have the limits been? 300A by Kramnik, has anyone else blown a bridge and measured the conditions? The irg4pc50Ud might be a decent upgrade...
IMO high-impedance primaries are actually less user-friendly - they require long on-times and run the transistors hotter.
I haven't tried the IRG4PC50UD yet...they seem roughly equivalent to the 60N60's I've been using and have a higher thermal impedance, plus they are a bit slower.
Killa-X wrote ...
I had to been running 50 primary current cycles...quiet a bit heh...plus i was burst-mode.
Once i replace the bridge later on i will leave everything the same and attempt to count the cycles..and measure the on vs off time, of when my coil went pop..
Most DRSSTC bridges have a snubber capacitor on them, is it not required on yours for some reason..?
not to mention i had 1 flash over before the video, i lifted the coil up by an inch, fixed the issues.
I had to been running 50 primary current cycles...quiet a bit heh...plus i was burst-mode.
Once i replace the bridge later on i will leave everything the same and attempt to count the cycles..and measure the on vs off time, of when my coil went pop..
Most DRSSTC bridges have a snubber capacitor on them, is it not required on yours for some reason..?
not to mention i had 1 flash over before the video, i lifted the coil up by an inch, fixed the issues.
Wow, nice work. 50 cycles is a lot...that's a couple hundred microseconds at your resonant frequency right? If you were variac'ing the bridge while keeping pulsewidths and such constant, have you tried holding the bridge at a constant voltage and raising pulsewidth until you find performance satisfactory?
My original excuse for not using a snubber was that i didn't have the board space for one (back when the board was etched on to 4x6" PCB stock from eBay). The current design uses a super-low-inductance laminated bus, so I haven't really found a need for a film cap yet. A film cap will most likely improve performance a bit - you can try soldering one directly to the capacitor terminals if you want.
As an FYI for everyone who has bought a board so far: the bleeders are meant to be soldered directly to the buscap terminals on the bottom of the board! Use bleeders!
Re: oneTesla - a small single-board DRSSTC
Killa-X, Tue Jul 31 2012, 11:53PM
I can see, i have a few caps but they maybe too small for snubber use. Its a 400V 1uF capacitor, 0.007ohm ESR.
I only messed with the duty cycle for making the arcs have some meat to them, and not be thin strains of hair, and its roughly around that 200Khz zone.
Killa-X, Tue Jul 31 2012, 11:53PM
I can see, i have a few caps but they maybe too small for snubber use. Its a 400V 1uF capacitor, 0.007ohm ESR.
I only messed with the duty cycle for making the arcs have some meat to them, and not be thin strains of hair, and its roughly around that 200Khz zone.
Re: oneTesla - a small single-board DRSSTC
Dr. ISOTOP, Wed Aug 01 2012, 12:06AM
1uF seems reasonable...you just need a film cap to neutralize the ESR of the electrolytics.
Dr. ISOTOP, Wed Aug 01 2012, 12:06AM
1uF seems reasonable...you just need a film cap to neutralize the ESR of the electrolytics.
Re: oneTesla - a small single-board DRSSTC
Killa-X, Wed Aug 01 2012, 12:27AM
Well. Let me put things this way. On my scope, if i set it to about 20 cycles, it sounds like its really really low duty cycle. maybe 10% or so. I had it, at my 555 interrupters max. meaning, enough that my scope either showed a very SOLID green waveform (meaning HUNDREDS of cycles) or, when i was viewing a sample of 20 cycles, it actually showed a total of 3 levels.
Basically, im not going to count how many cycles that video was. its gotta be well over 100-200 cycles. VERY likely 50% duty, which i can tell because my variac hums quiet a bit with 20VAC in when i was doing non-burst mode. Oh well, lessons learned I guess.
Killa-X, Wed Aug 01 2012, 12:27AM
Well. Let me put things this way. On my scope, if i set it to about 20 cycles, it sounds like its really really low duty cycle. maybe 10% or so. I had it, at my 555 interrupters max. meaning, enough that my scope either showed a very SOLID green waveform (meaning HUNDREDS of cycles) or, when i was viewing a sample of 20 cycles, it actually showed a total of 3 levels.
Basically, im not going to count how many cycles that video was. its gotta be well over 100-200 cycles. VERY likely 50% duty, which i can tell because my variac hums quiet a bit with 20VAC in when i was doing non-burst mode. Oh well, lessons learned I guess.
Re: oneTesla - a small single-board DRSSTC
Daniel Kramnik, Wed Aug 01 2012, 07:48PM
I killed my bridge running ~350A at up to 120uS on-time and continuous polyphonic operation for about a minute with ~14" white hot ground strikes (this was with a smaller coil than the 23" spark one).
I think that so long as you keep it from ground striking too much, provide adequate cooling, and avoid long runs with polyphony, it should be able to sustain that level of operation, although I personally prefer to turn down the pulsewidths and keep running it with polyphony. As far as I can tell, my failure was caused by overheating, not overcurrent - the transistors were burning hot!
It would definitely be worthwhile to try the irg4pc50Ud and see how far we can push it! At the moment, I think this coil can either work as a polyphonic musical DRSSTC demo with lower pulsewidths, higher coupling, and ~12 - 14" sparks, or just as a pure sparklength demo with higher pulsewidths, looser coupling, short run times, and 23" ground strikes.
The main motivation for not using a snubber is the laminated bus, and the fact that this allows us to keep the buscaps very close to the IGBTs. I tried deadbugging a 1uF 400V ASC snubber capacitor across the buscaps on the bottom of the board, but I didn't notice any difference when running with the primary/secondary with higher coupling and lower pulsewidth. It could definitely have helped though, since I only ran it up to 23" using the looser-coupled primary and secondary with the snubber in place. It's definitely worthwhile to try adding one in your case, I think. I'd also go lower on the resonant frequency, if possible.
Good luck!
Daniel Kramnik, Wed Aug 01 2012, 07:48PM
ben123324 wrote ...
What exactly have the limits been? 300A by Kramnik, has anyone else blown a bridge and measured the conditions? The irg4pc50Ud might be a decent upgrade...
What exactly have the limits been? 300A by Kramnik, has anyone else blown a bridge and measured the conditions? The irg4pc50Ud might be a decent upgrade...
I killed my bridge running ~350A at up to 120uS on-time and continuous polyphonic operation for about a minute with ~14" white hot ground strikes (this was with a smaller coil than the 23" spark one).
I think that so long as you keep it from ground striking too much, provide adequate cooling, and avoid long runs with polyphony, it should be able to sustain that level of operation, although I personally prefer to turn down the pulsewidths and keep running it with polyphony. As far as I can tell, my failure was caused by overheating, not overcurrent - the transistors were burning hot!
It would definitely be worthwhile to try the irg4pc50Ud and see how far we can push it! At the moment, I think this coil can either work as a polyphonic musical DRSSTC demo with lower pulsewidths, higher coupling, and ~12 - 14" sparks, or just as a pure sparklength demo with higher pulsewidths, looser coupling, short run times, and 23" ground strikes.
Killa-X wrote ...
Most DRSSTC bridges have a snubber capacitor on them, is it not required on yours for some reason..?
Most DRSSTC bridges have a snubber capacitor on them, is it not required on yours for some reason..?
The main motivation for not using a snubber is the laminated bus, and the fact that this allows us to keep the buscaps very close to the IGBTs. I tried deadbugging a 1uF 400V ASC snubber capacitor across the buscaps on the bottom of the board, but I didn't notice any difference when running with the primary/secondary with higher coupling and lower pulsewidth. It could definitely have helped though, since I only ran it up to 23" using the looser-coupled primary and secondary with the snubber in place. It's definitely worthwhile to try adding one in your case, I think. I'd also go lower on the resonant frequency, if possible.
Good luck!
Re: oneTesla - a small single-board DRSSTC
dude_500, Wed Aug 01 2012, 08:52PM
You're running your bridge at only 20VAC? You should turn that way up and lower duty cycle. DRSSTC's want more voltage and less duty cycle to make long sparks. You'll have less loss and way more spark with more voltage.
dude_500, Wed Aug 01 2012, 08:52PM
Killa-X wrote ...
Basically, im not going to count how many cycles that video was. its gotta be well over 100-200 cycles. VERY likely 50% duty, which i can tell because my variac hums quiet a bit with 20VAC in when i was doing non-burst mode. Oh well, lessons learned I guess.
Basically, im not going to count how many cycles that video was. its gotta be well over 100-200 cycles. VERY likely 50% duty, which i can tell because my variac hums quiet a bit with 20VAC in when i was doing non-burst mode. Oh well, lessons learned I guess.
You're running your bridge at only 20VAC? You should turn that way up and lower duty cycle. DRSSTC's want more voltage and less duty cycle to make long sparks. You'll have less loss and way more spark with more voltage.
Re: oneTesla - a small single-board DRSSTC
Killa-X, Wed Aug 01 2012, 09:38PM
Yeah I can't go lower frequency because I'm not going to buy more wire, have 3 coils for 200khz made of 34 awg so, putting them to use.
I said 20vac because any more and I'd break the breaker. That's what I was apparently running when I killed the bridge in burst mode at 120v. That video was full mains power, in burst mode, so doesn't draw near as much power as it would in a constant interruption tone.
Also I know coils like higher voltages. I run my 7' DRSSTC at 10 cycles (50khz) 390v for now...so..oh well, live and learn :). As cheap as these igbts are, was worth it.
Killa-X, Wed Aug 01 2012, 09:38PM
Yeah I can't go lower frequency because I'm not going to buy more wire, have 3 coils for 200khz made of 34 awg so, putting them to use.
I said 20vac because any more and I'd break the breaker. That's what I was apparently running when I killed the bridge in burst mode at 120v. That video was full mains power, in burst mode, so doesn't draw near as much power as it would in a constant interruption tone.
Also I know coils like higher voltages. I run my 7' DRSSTC at 10 cycles (50khz) 390v for now...so..oh well, live and learn :). As cheap as these igbts are, was worth it.
Re: oneTesla - a small single-board DRSSTC
Daniel Kramnik, Thu Aug 02 2012, 01:39PM
Have you actually measured the current that it draws? It seems strange that you're pulling so much current at such a low voltage; I clamp-metered my coil drawing around 1.5 - 2A with 1' sparks (albeit with much lower pulsewidths than you're running!). Try checking the diodes, perhaps? The problem you're describing (high current draw, short sparks) seems like it could be attributed to a blown rectifier.
Daniel Kramnik, Thu Aug 02 2012, 01:39PM
Killa-X wrote ...
I said 20vac because any more and I'd break the breaker. That's what I was apparently running when I killed the bridge in burst mode at 120v. That video was full mains power, in burst mode, so doesn't draw near as much power as it would in a constant interruption tone.
I said 20vac because any more and I'd break the breaker. That's what I was apparently running when I killed the bridge in burst mode at 120v. That video was full mains power, in burst mode, so doesn't draw near as much power as it would in a constant interruption tone.
Have you actually measured the current that it draws? It seems strange that you're pulling so much current at such a low voltage; I clamp-metered my coil drawing around 1.5 - 2A with 1' sparks (albeit with much lower pulsewidths than you're running!). Try checking the diodes, perhaps? The problem you're describing (high current draw, short sparks) seems like it could be attributed to a blown rectifier.
Re: oneTesla - a small single-board DRSSTC
Killa-X, Thu Aug 02 2012, 06:18PM
when your running THAR many cycles its no surprise i was drawing a chunk :P way too much lol - my fault.
My coil: 178khz or ~5.6uS
The ring-up time period until ring down: 170uS which is 5.88khz.
Can you do the math and figure this is 3.3% duty cycle..?
Now this is a LOOOOOOOOOT less cycles than i was doing when it blew. I recorded a video, testing different frequencys. I did not use an amp meter, because I knew i wouldnt pull much at all. But, I maxed my variac to the point it wouldnt go any higher. On my variac, this is 130VAC. So, if a perfect world, no voltage drop, you'd expect 367.64 Volts on the bridge. Amperage by then, only by a guess (for sure below 300A) was probably 280A.
I counted 32 positive spikes on the current waveform, so i can assume about 32 cycles to peak.
Still getting around that 20+ inch spark range, just thinner arcs obviously. My only question would be...How much higher could I safely go in on-time? I need to build a better primary, as this was just for testing. Once im in that 100V or more range, my waveform turns from a single climb, to two bumps. Which, I'm assuming means the sparks are drawing it prity damn close to resonance. Did have a nice ring to it at the higher voltages.
Would my sparks be longer / better going out the side? Also, short or long breakout? It seems on my big DRSSTC, a 4" breakout was better than a 14" breakout...
Killa-X, Thu Aug 02 2012, 06:18PM
when your running THAR many cycles its no surprise i was drawing a chunk :P way too much lol - my fault.
My coil: 178khz or ~5.6uS
The ring-up time period until ring down: 170uS which is 5.88khz.
Can you do the math and figure this is 3.3% duty cycle..?
Now this is a LOOOOOOOOOT less cycles than i was doing when it blew. I recorded a video, testing different frequencys. I did not use an amp meter, because I knew i wouldnt pull much at all. But, I maxed my variac to the point it wouldnt go any higher. On my variac, this is 130VAC. So, if a perfect world, no voltage drop, you'd expect 367.64 Volts on the bridge. Amperage by then, only by a guess (for sure below 300A) was probably 280A.
I counted 32 positive spikes on the current waveform, so i can assume about 32 cycles to peak.
Still getting around that 20+ inch spark range, just thinner arcs obviously. My only question would be...How much higher could I safely go in on-time? I need to build a better primary, as this was just for testing. Once im in that 100V or more range, my waveform turns from a single climb, to two bumps. Which, I'm assuming means the sparks are drawing it prity damn close to resonance. Did have a nice ring to it at the higher voltages.
Would my sparks be longer / better going out the side? Also, short or long breakout? It seems on my big DRSSTC, a 4" breakout was better than a 14" breakout...
Re: oneTesla - a small single-board DRSSTC
HV Enthusiast, Fri Aug 03 2012, 03:03PM
Hey there Dr. ISOTOP,
Just saw your project. Very nice design! Cool to see you using the CST current transformers. They are really great for the price and they are good up to about 1000A peak current. Good choice on IGBTs too. One of the co-ops working for me right now is presently working on the next iteration of our microBrute DRSSTC and that is one of the IGBTs that is being tested. You might also want to try some of the IXYS TO-247 based IGBTs of similar specs. They are similar in price.
Just one suggestion, since you are going to be selling these, i would make sure you sell them with fusing onboard (if you don't already have them) Line power is very dangerous and if something shorts out with fusing, it could make things very ugly fast. Also, if you are not already doing so, make sure the heatsinks are grounded to chassis (earth ground). So if you get punch thru on the devices, you don't have dangerous voltage exposed on your heatsink.
Keep up the good work! Awesome stuff!
HV Enthusiast, Fri Aug 03 2012, 03:03PM
Hey there Dr. ISOTOP,
Just saw your project. Very nice design! Cool to see you using the CST current transformers. They are really great for the price and they are good up to about 1000A peak current. Good choice on IGBTs too. One of the co-ops working for me right now is presently working on the next iteration of our microBrute DRSSTC and that is one of the IGBTs that is being tested. You might also want to try some of the IXYS TO-247 based IGBTs of similar specs. They are similar in price.
Just one suggestion, since you are going to be selling these, i would make sure you sell them with fusing onboard (if you don't already have them) Line power is very dangerous and if something shorts out with fusing, it could make things very ugly fast. Also, if you are not already doing so, make sure the heatsinks are grounded to chassis (earth ground). So if you get punch thru on the devices, you don't have dangerous voltage exposed on your heatsink.
Keep up the good work! Awesome stuff!
Re: oneTesla - a small single-board DRSSTC
Dr. ISOTOP, Fri Aug 03 2012, 10:54PM
Killa-X asked me some questions about the interrupter, so I'll try to answer them to the best of my abilities (Kramnik designed it, so he can fill in the gaps for me)
The interrupter also has selectable modes of operation, either MIDI or standard DRSSTC pulsed mode, and a programming jack for firmware upgrades.
Thanks for the kind words
Do you know of a good supplier for IXYS IGBT's? I've looked at them before, but they seem pretty hard to get a hold of.
Dr. ISOTOP, Fri Aug 03 2012, 10:54PM
Killa-X asked me some questions about the interrupter, so I'll try to answer them to the best of my abilities (Kramnik designed it, so he can fill in the gaps for me)
Killa-X via PM wrote ...
Very cool. I updated my post with a video and coil details.
May I ask what chip your basing it around? Pondering if I have it around my room, as if its ATMEGA class, you cant put an ATMEGA16 code on a ATMEGA32..as when you get into timers and stuff (if you are) you can get into said variables that exist only to that chip...as every chip is different. ADC's for example..
Err...I don't remember; Kramnik will have to answer this one.Very cool. I updated my post with a video and coil details.
May I ask what chip your basing it around? Pondering if I have it around my room, as if its ATMEGA class, you cant put an ATMEGA16 code on a ATMEGA32..as when you get into timers and stuff (if you are) you can get into said variables that exist only to that chip...as every chip is different. ADC's for example..
wrote ...
Will it have some sort of limiter to prevent going over X duty cycle / on time?
It has a note table of appropriate pulse lengths for the coil its being run with. The duty-cycle limiter idea seems like a good idea; if it doesn't already exist we'll be sure to add it.Will it have some sort of limiter to prevent going over X duty cycle / on time?
wrote ...
How many voices can it play at once? And does it use an SD chip for .midi file, or some manual method of transcribing?
Two notes. The board has a MIDI jack on it for taking streams of MIDI notes from a host device; I believe there is also a computer-side application that can send arbitrary .midi files to the interrupter.How many voices can it play at once? And does it use an SD chip for .midi file, or some manual method of transcribing?
The interrupter also has selectable modes of operation, either MIDI or standard DRSSTC pulsed mode, and a programming jack for firmware upgrades.
EasternVoltageResearch wrote ...
Hey there Dr. ISOTOP,
Just saw your project. Very nice design! Cool to see you using the CST current transformers. They are really great for the price and they are good up to about 1000A peak current. Good choice on IGBTs too. One of the co-ops working for me right now is presently working on the next iteration of our microBrute DRSSTC and that is one of the IGBTs that is being tested. You might also want to try some of the IXYS TO-247 based IGBTs of similar specs. They are similar in price.
Just one suggestion, since you are going to be selling these, i would make sure you sell them with fusing onboard (if you don't already have them) Line power is very dangerous and if something shorts out with fusing, it could make things very ugly fast. Also, if you are not already doing so, make sure the heatsinks are grounded to chassis (earth ground). So if you get punch thru on the devices, you don't have dangerous voltage exposed on your heatsink.
Keep up the good work! Awesome stuff!
Hey there Dr. ISOTOP,
Just saw your project. Very nice design! Cool to see you using the CST current transformers. They are really great for the price and they are good up to about 1000A peak current. Good choice on IGBTs too. One of the co-ops working for me right now is presently working on the next iteration of our microBrute DRSSTC and that is one of the IGBTs that is being tested. You might also want to try some of the IXYS TO-247 based IGBTs of similar specs. They are similar in price.
Just one suggestion, since you are going to be selling these, i would make sure you sell them with fusing onboard (if you don't already have them) Line power is very dangerous and if something shorts out with fusing, it could make things very ugly fast. Also, if you are not already doing so, make sure the heatsinks are grounded to chassis (earth ground). So if you get punch thru on the devices, you don't have dangerous voltage exposed on your heatsink.
Keep up the good work! Awesome stuff!
Thanks for the kind words
Do you know of a good supplier for IXYS IGBT's? I've looked at them before, but they seem pretty hard to get a hold of.
Re: oneTesla - a small single-board DRSSTC
HV Enthusiast, Fri Aug 03 2012, 11:53PM
Best place is probably through your local IXYS sales rep.
Another good resource is Just enter the part number and they will give you all the suppliers that have stock of a particular part as well as price.
IXYS is also VERY good at samples. So if you call your local IXYS rep and discuss your project with them, they are almost always willing to provide you with samples of everything you need.
HV Enthusiast, Fri Aug 03 2012, 11:53PM
Best place is probably through your local IXYS sales rep.
Another good resource is
Just enter the part number and they will give you all the suppliers that have stock of a particular part as well as price.IXYS is also VERY good at samples. So if you call your local IXYS rep and discuss your project with them, they are almost always willing to provide you with samples of everything you need.
Re: oneTesla - a small single-board DRSSTC
Steve Ward, Mon Aug 06 2012, 04:39AM
Have you observed the switching waveforms and primary current during this condition? Maybe you can gain some insight as to what the devices are really putting up with during this condition.
I guess this is why i never settled for anything without active current limiting.
Steve Ward, Mon Aug 06 2012, 04:39AM
I killed my bridge running ~350A at up to 120uS on-time and continuous polyphonic operation for about a minute with ~14" white hot ground strikes (this was with a smaller coil than the 23" spark one).
Have you observed the switching waveforms and primary current during this condition? Maybe you can gain some insight as to what the devices are really putting up with during this condition.
I guess this is why i never settled for anything without active current limiting.
Re: oneTesla - a small single-board DRSSTC
Dr. ISOTOP, Thu Aug 09 2012, 12:42AM
@Killa-X: the interrupter uses an ATMEGA328P-PU
Dr. ISOTOP, Thu Aug 09 2012, 12:42AM
@Killa-X: the interrupter uses an ATMEGA328P-PU
Re: oneTesla - a small single-board DRSSTC
E.TexasTesla, Thu Aug 09 2012, 07:53PM
Just ordered on of your boards off ebay.
One quick question for you
will the FGH60N60SMD interchange with the FGH60N60SFD igbit?
Both the data sheets look similar except for saturation voltage.
Thanks.
E.TexasTesla, Thu Aug 09 2012, 07:53PM
Just ordered on of your boards off ebay.
One quick question for you
will the FGH60N60SMD interchange with the FGH60N60SFD igbit?
Both the data sheets look similar except for saturation voltage.
Thanks.
Re: oneTesla - a small single-board DRSSTC
Ben Solon, Thu Aug 09 2012, 08:17PM
any reasonably rated igbt will "work", its efficiency that changes. and with a higher Vce sat. the igbt will drop more voltage for the same current, limiting the power you can push before burning past the 150deg C rating of semiconductors.
Ben Solon, Thu Aug 09 2012, 08:17PM
any reasonably rated igbt will "work", its efficiency that changes. and with a higher Vce sat. the igbt will drop more voltage for the same current, limiting the power you can push before burning past the 150deg C rating of semiconductors.
Re: oneTesla - a small single-board DRSSTC
Dr. ISOTOP, Thu Aug 09 2012, 09:03PM
The SMD is definitely the better IGBT, since it has lower Vce and, more importantly, is faster.
Dr. ISOTOP, Thu Aug 09 2012, 09:03PM
E.TexasTesla wrote ...
Just ordered on of your boards off ebay.
One quick question for you
will the FGH60N60SMD interchange with the FGH60N60SFD igbit?
Both the data sheets look similar except for saturation voltage.
Thanks. Chris "Jencoautomotive"
Just ordered on of your boards off ebay.
One quick question for you
will the FGH60N60SMD interchange with the FGH60N60SFD igbit?
Both the data sheets look similar except for saturation voltage.
Thanks. Chris "Jencoautomotive"
The SMD is definitely the better IGBT, since it has lower Vce and, more importantly, is faster.
Re: oneTesla - a small single-board DRSSTC
E.TexasTesla, Thu Aug 09 2012, 09:36PM
Thanks for the information. Im looking forward to the buildup.:-)
E.TexasTesla, Thu Aug 09 2012, 09:36PM
Thanks for the information. Im looking forward to the buildup.:-)
Re: oneTesla - a small single-board DRSSTC
Dr. ISOTOP, Sun Aug 12 2012, 05:48AM
Lots of delicious oneTeslas:
Dr. ISOTOP, Sun Aug 12 2012, 05:48AM
Lots of delicious oneTeslas:
Re: oneTesla - a small single-board DRSSTC
Killa-X, Sun Aug 12 2012, 04:34PM
Lot more turns than I use but hey, different cores - different winding!
Now you just need to wire them up and put 8 coils evenly spaced all around you playing music in accordance to surround sound...
Killa-X, Sun Aug 12 2012, 04:34PM
Lot more turns than I use but hey, different cores - different winding!
Now you just need to wire them up and put 8 coils evenly spaced all around you playing music in accordance to surround sound...
Re: oneTesla - a small single-board DRSSTC
Dr. ISOTOP, Fri Aug 17 2012, 08:16PM
^putting all those nuts onto those threaded rods was an interesting experience
Dr. ISOTOP, Fri Aug 17 2012, 08:16PM
^putting all those nuts onto those threaded rods was an interesting experience
Re: oneTesla - a small single-board DRSSTC
Ben Solon, Fri Aug 17 2012, 09:41PM
parallel them
Ben Solon, Fri Aug 17 2012, 09:41PM
parallel them
Re: oneTesla - a small single-board DRSSTC
E.TexasTesla, Fri Aug 24 2012, 01:56PM
Sale date: 08/09/12
Tracking number: --
Estimated Delivery: 08/15/12 - 08/22/12
Still waiting. ;)
E.TexasTesla, Fri Aug 24 2012, 01:56PM
Daniel Kramnik wrote ...
Boards are on sale now! (link)
I'll admit they are a bit pricey, but you get free fast shipping, and profits go towards improving oneTesla =)
Boards are on sale now! (link)
I'll admit they are a bit pricey, but you get free fast shipping, and profits go towards improving oneTesla =)
Sale date: 08/09/12
Tracking number: --
Estimated Delivery: 08/15/12 - 08/22/12
Still waiting. ;)
Re: oneTesla - a small single-board DRSSTC
Dr. ISOTOP, Fri Aug 24 2012, 05:32PM
Sent you a PM hopefully rectifying this issue.
Also, I have interrupter boards now, which are completely untested. PM me if you're interested in alpha-testing one, and I'll see if I can scratch up some documentation to make things work.
Dr. ISOTOP, Fri Aug 24 2012, 05:32PM
E.TexasTesla wrote ...
Sale date: 08/09/12
Tracking number: --
Estimated Delivery: 08/15/12 - 08/22/12
Still waiting. ;)
Daniel Kramnik wrote ...
Boards are on sale now! (link)
I'll admit they are a bit pricey, but you get free fast shipping, and profits go towards improving oneTesla =)
Boards are on sale now! (link)
I'll admit they are a bit pricey, but you get free fast shipping, and profits go towards improving oneTesla =)
Sale date: 08/09/12
Tracking number: --
Estimated Delivery: 08/15/12 - 08/22/12
Still waiting. ;)
Sent you a PM hopefully rectifying this issue.
Also, I have interrupter boards now, which are completely untested. PM me if you're interested in alpha-testing one, and I'll see if I can scratch up some documentation to make things work.
Re: oneTesla - a small single-board DRSSTC
E.TexasTesla, Thu Sept 06 2012, 07:02PM
Boards came in today 9/11/2012. They look nice.
Thanks.
E.TexasTesla, Thu Sept 06 2012, 07:02PM
Boards came in today 9/11/2012. They look nice.
Thanks.
Re: oneTesla - a small single-board DRSSTC
Jiffycoil, Sat Sept 15 2012, 04:49PM
I've ordered a board and look forward to posting my build.
Jiffycoil, Sat Sept 15 2012, 04:49PM
I've ordered a board and look forward to posting my build.
Re: oneTesla - a small single-board DRSSTC
Jiffycoil, Tue Sept 18 2012, 05:09PM
Hey Dr.
Please check your Ebay and Paypal. I made a purchase
Sale date: 09/04/12
Tracking number: --
Estimated Delivery: 09/10/12 - 09/17/12
Thanks
Jiffycoil, Tue Sept 18 2012, 05:09PM
Hey Dr.
Please check your Ebay and Paypal. I made a purchase
Sale date: 09/04/12
Tracking number: --
Estimated Delivery: 09/10/12 - 09/17/12
Thanks
Re: oneTesla - a small single-board DRSSTC
Dr. ISOTOP, Tue Sept 18 2012, 06:54PM
PM'ed ya about it, sorry for the delay.
Dr. ISOTOP, Tue Sept 18 2012, 06:54PM
Jiffycoil wrote ...
Hey Dr.
Please check your Ebay and Paypal. I made a purchase
Sale date: 09/04/12
Tracking number: --
Estimated Delivery: 09/10/12 - 09/17/12
Thanks
Hey Dr.
Please check your Ebay and Paypal. I made a purchase
Sale date: 09/04/12
Tracking number: --
Estimated Delivery: 09/10/12 - 09/17/12
Thanks
PM'ed ya about it, sorry for the delay.
Re: oneTesla - a small single-board DRSSTC
E.TexasTesla, Sun Sept 23 2012, 01:04AM
Started buildup tonight.
Two things I feel are worth mentioning
1. Power cord is not standard. I have 5 laptop power supplies and all have middle pin V+
The board connector is wired for middle pin ground. Easy switch by cutting cord.
2. A 74hc14 is not a good substitute for the recomended 74ls14n
It will not switch the interupt signal on pin 12.
Edit: interupt signal good to pin 13 on 74hc14 but pin 12 was pulled high "not toggling"
I found the proper 74ls14n and pin 12 is toggling but still no sparks.
No output from gate drivers.
I think the problem is my optical sensor. I used an if-d96f because I had a drawer full, but the output
may not be correct for the board. IF-d95T on order.
E.TexasTesla, Sun Sept 23 2012, 01:04AM
Started buildup tonight.
Two things I feel are worth mentioning
1. Power cord is not standard. I have 5 laptop power supplies and all have middle pin V+
The board connector is wired for middle pin ground. Easy switch by cutting cord.
2. A 74hc14 is not a good substitute for the recomended 74ls14n
It will not switch the interupt signal on pin 12.
Edit: interupt signal good to pin 13 on 74hc14 but pin 12 was pulled high "not toggling"
I found the proper 74ls14n and pin 12 is toggling but still no sparks.
No output from gate drivers.
I think the problem is my optical sensor. I used an if-d96f because I had a drawer full, but the output
may not be correct for the board. IF-d95T on order.
Re: oneTesla - a small single-board DRSSTC
Dr. ISOTOP, Sun Sept 23 2012, 04:06AM
(1) Yes, this will be fixed in the retail release
(2) The 74HCT14 is a good substitute, as it has TTL compatible logic levels. Also, the HC should work fine; what problems are you having, exactly?
Dr. ISOTOP, Sun Sept 23 2012, 04:06AM
E.TexasTesla wrote ...
Started buildup tonight.
Two things I feel are worth mentioning
1. Power cord is not standard. I have 5 laptop power supplies and all have middle pin V+
The board connector is wired for middle pin ground. Easy switch by cutting cord.
2. A 74hc14 is not a good substitute for the recomended 74ls14n
It will not swith the interupt signal on pin 12.
Started buildup tonight.
Two things I feel are worth mentioning
1. Power cord is not standard. I have 5 laptop power supplies and all have middle pin V+
The board connector is wired for middle pin ground. Easy switch by cutting cord.
2. A 74hc14 is not a good substitute for the recomended 74ls14n
It will not swith the interupt signal on pin 12.
(1) Yes, this will be fixed in the retail release
(2) The 74HCT14 is a good substitute, as it has TTL compatible logic levels. Also, the HC should work fine; what problems are you having, exactly?
Re: oneTesla - a small single-board DRSSTC
Killa-X, Sun Sept 23 2012, 04:53PM
Its not standard? Heck i have 30 cords laying around in a box from computer power supplies. I just randomly grabbed one, chucked it into the connector,and bam..worked.
Cant recall if this was already stated or known but, Do please add an OCD. I installed my own, but a DRSSTC really should have one to help prevent issues. For people that know what they are doing, its fine. But for newer people, maybe a first DRSSTC person, if they just kill that PWM pot on the interrupter and blow the bridge because it ran >300A .. yeah.
Please do consider it :)
Killa-X, Sun Sept 23 2012, 04:53PM
Its not standard? Heck i have 30 cords laying around in a box from computer power supplies. I just randomly grabbed one, chucked it into the connector,and bam..worked.
Cant recall if this was already stated or known but, Do please add an OCD. I installed my own, but a DRSSTC really should have one to help prevent issues. For people that know what they are doing, its fine. But for newer people, maybe a first DRSSTC person, if they just kill that PWM pot on the interrupter and blow the bridge because it ran >300A .. yeah.
Please do consider it :)
Re: oneTesla - a small single-board DRSSTC
Dr. ISOTOP, Sun Sept 23 2012, 07:24PM
The decision not to have an OCD was an active one; it cuts costs and also eliminates the need to trim the OCD pot.
With that being said, there are potential plans for a slightly larger full-bridge version of the board, which will probably have OCD and such.
Also, I'm curious, how did you implement an add-on OCD? If it was integrated into the interrupter, I'd be interested in adding it to the kit.
Also, I think he was referring to the reversed DC jack on the board, which was an unfortunate layout mistake on my part.
As an added note, if you want to have a coil with high coupling (to reduce pulsewidths and hence stress during music), this stuff: is great for insulating the secondary.
Dr. ISOTOP, Sun Sept 23 2012, 07:24PM
Killa-X wrote ...
Its not standard? Heck i have 30 cords laying around in a box from computer power supplies. I just randomly grabbed one, chucked it into the connector,and bam..worked.
Cant recall if this was already stated or known but, Do please add an OCD. I installed my own, but a DRSSTC really should have one to help prevent issues. For people that know what they are doing, its fine. But for newer people, maybe a first DRSSTC person, if they just kill that PWM pot on the interrupter and blow the bridge because it ran >300A .. yeah.
Please do consider it :)
Its not standard? Heck i have 30 cords laying around in a box from computer power supplies. I just randomly grabbed one, chucked it into the connector,and bam..worked.
Cant recall if this was already stated or known but, Do please add an OCD. I installed my own, but a DRSSTC really should have one to help prevent issues. For people that know what they are doing, its fine. But for newer people, maybe a first DRSSTC person, if they just kill that PWM pot on the interrupter and blow the bridge because it ran >300A .. yeah.
Please do consider it :)
The decision not to have an OCD was an active one; it cuts costs and also eliminates the need to trim the OCD pot.
With that being said, there are potential plans for a slightly larger full-bridge version of the board, which will probably have OCD and such.
Also, I'm curious, how did you implement an add-on OCD? If it was integrated into the interrupter, I'd be interested in adding it to the kit.
Also, I think he was referring to the reversed DC jack on the board, which was an unfortunate layout mistake on my part.
As an added note, if you want to have a coil with high coupling (to reduce pulsewidths and hence stress during music), this stuff:
is great for insulating the secondary.Re: oneTesla - a small single-board DRSSTC
Patrick, Sun Sept 23 2012, 10:41PM
Patrick, Sun Sept 23 2012, 10:41PM
Dr. ISOTOP wrote ...
, this stuff: is great for insulating the secondary.
what is this material? generic chemaical names please.., this stuff:
is great for insulating the secondary.Re: oneTesla - a small single-board DRSSTC
Steve Conner, Mon Sept 24 2012, 09:37AM
Looks like ethylene-propylene rubber. I'm going to guess it's similar to self-amalgamating electrical tape.
If you're not careful, adding dielectric to an air-insulated HF transformer can make flashover problems worse.
Steve Conner, Mon Sept 24 2012, 09:37AM
Looks like ethylene-propylene rubber. I'm going to guess it's similar to self-amalgamating electrical tape.
If you're not careful, adding dielectric to an air-insulated HF transformer can make flashover problems worse.
Re: oneTesla - a small single-board DRSSTC
E.TexasTesla, Thu Sept 27 2012, 12:47AM
Need some advise on this board. After two pairs of IRG4PC50UDs im pulling my hair out.
coil specs :
3 x 8 secondary 28 gauge wire
2 x 10 inch torid
5 turns primary wound over secondary with insulation
Steve Wards universal driver
I get weak sparks for about 3 seconds with duty cycle on driver set to lowest rep.
Then both igbts blow.
The last time around it blew a trace off the board.
(Easternvoltage, I found a fuse of sorts LOL)
My gate signals look good at both igbts. I beleive it was around 2-3 vac.
Do you think I had a primary insulation fault?
I think I will add some TVS to this circuit.
E.TexasTesla, Thu Sept 27 2012, 12:47AM
Need some advise on this board. After two pairs of IRG4PC50UDs im pulling my hair out.
coil specs :
3 x 8 secondary 28 gauge wire
2 x 10 inch torid
5 turns primary wound over secondary with insulation
Steve Wards universal driver
I get weak sparks for about 3 seconds with duty cycle on driver set to lowest rep.
Then both igbts blow.
The last time around it blew a trace off the board.
(Easternvoltage, I found a fuse of sorts LOL)
My gate signals look good at both igbts. I beleive it was around 2-3 vac.
Do you think I had a primary insulation fault?
I think I will add some TVS to this circuit.
Re: oneTesla - a small single-board DRSSTC
Dr. ISOTOP, Thu Sept 27 2012, 02:04AM
You're running possibly detuned with way too high of a resonant frequency there, plus the IRG4PC50UD has quite a bit more turn-off delay than the FGH60N60SMD. What bus voltage were you running?
Also, if your gate signals were 3VAC then something is wrong.
I would highly advise duplicating the specs in the first post, unless you're explicitly trying to do development work to push the design's limits.
Unrelated to this particular issue, here's a rough draft of a troubleshooting guide:
Note that it's for an unreleased interrupter, but the general idea should be the same.
It may or may not be perfect, but will probably be of some help. Your feedback is appreciated
Also, for you guys out there who have boards:
(1) Thin wire is a must when constructing the secondary.
(2) Proper shielding on the interrupter is also a must (or a really long fiber cable, at least a couple meters long)
(3) Use fast IGBT's.
(4) Use a variac while testing if you have one. If you don't have a variac, make sure that the GDT is phased properly; no amount of fuses can save your board if the bridge shoots through with 400V on the bus.
Dr. ISOTOP, Thu Sept 27 2012, 02:04AM
E.TexasTesla wrote ...
Need some advise on this board. After two pairs of IRG4PC50UDs im pulling my hair out.
coil specs :
3 x 8 secondary 28 gauge wire
2 x 10 inch torid
5 turns primary wound over secondary with insulation
Steve Wards universal driver
I get weak sparks for about 3 seconds with duty cycle on driver set to lowest rep.
Then both igbts blow.
The last time around it blew a trace off the board.
(Easternvoltage, I found a fuse of sorts LOL)
My gate signals look good at both igbts. I beleive it was around 2-3 vac.
Do you think I had a primary insulation fault?
I think I will add some TVS to this circuit.
Need some advise on this board. After two pairs of IRG4PC50UDs im pulling my hair out.
coil specs :
3 x 8 secondary 28 gauge wire
2 x 10 inch torid
5 turns primary wound over secondary with insulation
Steve Wards universal driver
I get weak sparks for about 3 seconds with duty cycle on driver set to lowest rep.
Then both igbts blow.
The last time around it blew a trace off the board.
(Easternvoltage, I found a fuse of sorts LOL)
My gate signals look good at both igbts. I beleive it was around 2-3 vac.
Do you think I had a primary insulation fault?
I think I will add some TVS to this circuit.
You're running possibly detuned with way too high of a resonant frequency there, plus the IRG4PC50UD has quite a bit more turn-off delay than the FGH60N60SMD. What bus voltage were you running?
Also, if your gate signals were 3VAC then something is wrong.
I would highly advise duplicating the specs in the first post, unless you're explicitly trying to do development work to push the design's limits.
Unrelated to this particular issue, here's a rough draft of a troubleshooting guide:
Note that it's for an unreleased interrupter, but the general idea should be the same.
It may or may not be perfect, but will probably be of some help. Your feedback is appreciated
Also, for you guys out there who have boards:
(1) Thin wire is a must when constructing the secondary.
(2) Proper shielding on the interrupter is also a must (or a really long fiber cable, at least a couple meters long)
(3) Use fast IGBT's.
(4) Use a variac while testing if you have one. If you don't have a variac, make sure that the GDT is phased properly; no amount of fuses can save your board if the bridge shoots through with 400V on the bus.
Re: oneTesla - a small single-board DRSSTC
Jiffycoil, Fri Sept 28 2012, 04:28PM
My boards arrived today. They look really nice and of excellent quality. I've been following the thread and have learned quite a bit of do's and dont's which should make assembly easier.
Jiffycoil, Fri Sept 28 2012, 04:28PM
My boards arrived today. They look really nice and of excellent quality. I've been following the thread and have learned quite a bit of do's and dont's which should make assembly easier.
Re: oneTesla - a small single-board DRSSTC
Killa-X, Fri Sept 28 2012, 09:12PM
I love your diver man, but the MMC, shes cooking for me! 250A primary current, 120VAC input...after playing Canon the single MMC cap was 150F, my primary was 125F.
But -- I'm not complaining yet! My coil was NOT tuned. Stupid running a coil like this not tuned but hey, It's my parts! But works damn good :)
First power test after rebuild -- NOT IN TUNE -- French Can Can midi
Secodn power test after rebuild -- NOT IN TUNE -- Canon midi
Your caps are only 6ARMS and well .. Not enough for this kind of use :)
Killa-X, Fri Sept 28 2012, 09:12PM
I love your diver man, but the MMC, shes cooking for me! 250A primary current, 120VAC input...after playing Canon the single MMC cap was 150F, my primary was 125F.
But -- I'm not complaining yet! My coil was NOT tuned. Stupid running a coil like this not tuned but hey, It's my parts! But works damn good :)
First power test after rebuild -- NOT IN TUNE -- French Can Can midi
Secodn power test after rebuild -- NOT IN TUNE -- Canon midi
Your caps are only 6ARMS and well .. Not enough for this kind of use :)
Re: oneTesla - a small single-board DRSSTC
Jiffycoil, Fri Sept 28 2012, 09:42PM
Love the Can Can. Nice work.
Jiffycoil, Fri Sept 28 2012, 09:42PM
Love the Can Can. Nice work.
Re: oneTesla - a small single-board DRSSTC
technology man, Fri Sept 28 2012, 11:56PM
Could you ask me witch schematic/circuit programm did you use ?
technology man, Fri Sept 28 2012, 11:56PM
Could you ask me witch schematic/circuit programm did you use ?
Re: oneTesla - a small single-board DRSSTC
Dr. ISOTOP, Sat Sept 29 2012, 02:12PM
Eagle
What pulse widths are you running? I've never had problems with MMC heating running (fairly short) pulse widths.
If your resonant frequency is low, you might be ringing the capacitor voltage high enough to break down the dielectric (Vpk = Ipk/(2pi*f*C))
Dr. ISOTOP, Sat Sept 29 2012, 02:12PM
technology man wrote ...
Could you ask me witch schematic/circuit programm did you use ?
Could you ask me witch schematic/circuit programm did you use ?
Eagle
Killa-X wrote ...
I love your diver man, but the MMC, shes cooking for me! 250A primary current, 120VAC input...after playing Canon the single MMC cap was 150F, my primary was 125F.
But -- I'm not complaining yet! My coil was NOT tuned. Stupid running a coil like this not tuned but hey, It's my parts! But works damn good :)
First power test after rebuild -- NOT IN TUNE -- French Can Can midi
Secodn power test after rebuild -- NOT IN TUNE -- Canon midi
Your caps are only 6ARMS and well .. Not enough for this kind of use :)
I love your diver man, but the MMC, shes cooking for me! 250A primary current, 120VAC input...after playing Canon the single MMC cap was 150F, my primary was 125F.
But -- I'm not complaining yet! My coil was NOT tuned. Stupid running a coil like this not tuned but hey, It's my parts! But works damn good :)
First power test after rebuild -- NOT IN TUNE -- French Can Can midi
Secodn power test after rebuild -- NOT IN TUNE -- Canon midi
Your caps are only 6ARMS and well .. Not enough for this kind of use :)
What pulse widths are you running? I've never had problems with MMC heating running (fairly short) pulse widths.
If your resonant frequency is low, you might be ringing the capacitor voltage high enough to break down the dielectric (Vpk = Ipk/(2pi*f*C))
Re: oneTesla - a small single-board DRSSTC
Jiffycoil, Sun Sept 30 2012, 01:34AM
I can't seem to get to this guide. Anyone else having this problem?
Jiffycoil, Sun Sept 30 2012, 01:34AM
Dr. ISOTOP wrote ...
Unrelated to this particular issue, here's a rough draft of a troubleshooting guide:
Unrelated to this particular issue, here's a rough draft of a troubleshooting guide:
I can't seem to get to this guide. Anyone else having this problem?
Re: oneTesla - a small single-board DRSSTC
Dr. ISOTOP, Sun Sept 30 2012, 02:19AM
Try this:
Dr. ISOTOP, Sun Sept 30 2012, 02:19AM
Try this:
Re: oneTesla - a small single-board DRSSTC
Jiffycoil, Sun Sept 30 2012, 02:56AM
Thanks. That works.
Jiffycoil, Sun Sept 30 2012, 02:56AM
Thanks. That works.
Re: oneTesla - a small single-board DRSSTC
Killa-X, Mon Oct 01 2012, 02:07AM
I'm running about 10 -15 cycles right now on its current setup ( 200khz with topload ) to run around 250 Amps.
It's no biggy to me. I have quiet a lot of MMC caps laying all over the place. Maybe fair enough to say im driving it differently I guess, either way even though im only drawing 2-3A from the wall, its close to the cap value of 6A when peaks are considered. Really to the datasheet 150F is well safe...
Killa-X, Mon Oct 01 2012, 02:07AM
I'm running about 10 -15 cycles right now on its current setup ( 200khz with topload ) to run around 250 Amps.
It's no biggy to me. I have quiet a lot of MMC caps laying all over the place. Maybe fair enough to say im driving it differently I guess, either way even though im only drawing 2-3A from the wall, its close to the cap value of 6A when peaks are considered. Really to the datasheet 150F is well safe...
Re: oneTesla - a small single-board DRSSTC
E.TexasTesla, Wed Oct 03 2012, 08:45PM
10 x FGH60N60SMD came in today from digikey
and 1.5 lb. spool of 36 awg wire came in from ebay.
Im amazed at how thin this wire is.
2.5 form with 10 inch of windings
E.TexasTesla, Wed Oct 03 2012, 08:45PM
10 x FGH60N60SMD came in today from digikey
and 1.5 lb. spool of 36 awg wire came in from ebay.
Im amazed at how thin this wire is.
2.5 form with 10 inch of windings
Re: oneTesla - a small single-board DRSSTC
Jiffycoil, Wed Oct 03 2012, 10:42PM
I have parts coming in tomorrow. Looking forward to this build.
Jiffycoil, Wed Oct 03 2012, 10:42PM
I have parts coming in tomorrow. Looking forward to this build.
Re: oneTesla - a small single-board DRSSTC
Killa-X, Thu Oct 04 2012, 06:06PM
Yeah I only used 36awg once and heh, that was a joy. Was easy to do, just took so long and seemed forever knowing it was a tiny coil, yet so many turns... But, I did mine was a 3.5 x 12.5 of 34awg. I was on a roll and cracked out 3 coils from a spare spools from school. So, they sat in my room for over a year and now I'm finally using one with a board. Going to build a second clone system once the first coil design performs greatly
Killa-X, Thu Oct 04 2012, 06:06PM
Yeah I only used 36awg once and heh, that was a joy. Was easy to do, just took so long and seemed forever knowing it was a tiny coil, yet so many turns... But, I did mine was a 3.5 x 12.5 of 34awg. I was on a roll and cracked out 3 coils from a spare spools from school. So, they sat in my room for over a year and now I'm finally using one with a board. Going to build a second clone system once the first coil design performs greatly
Re: oneTesla - a small single-board DRSSTC
Ben Solon, Thu Oct 04 2012, 08:08PM
see if you can phase the ~fres of each one 180 deg from each other. a cool addition to onetesla would be a simple jumper to do phase matching/opposing to multicoil systems. the only problem is matching the two coils to the same frequency...
Ben Solon, Thu Oct 04 2012, 08:08PM
Killa-X wrote ...
Going to build a second clone system once the first coil design performs greatly
Going to build a second clone system once the first coil design performs greatly
see if you can phase the ~fres of each one 180 deg from each other. a cool addition to onetesla would be a simple jumper to do phase matching/opposing to multicoil systems. the only problem is matching the two coils to the same frequency...
Re: oneTesla - a small single-board DRSSTC
Dr. ISOTOP, Sun Oct 14 2012, 08:35AM
Here are some SolidWorks and DXF files for a lasercut chassis for the coil:
Adjust for the kerf of your cutter as appropriate.
Dr. ISOTOP, Sun Oct 14 2012, 08:35AM
Here are some SolidWorks and DXF files for a lasercut chassis for the coil:
Adjust for the kerf of your cutter as appropriate.
Re: oneTesla - a small single-board DRSSTC
Jiffycoil, Wed Oct 17 2012, 05:10PM
Hi,
I was wondering if i could get the polyphonic code for the interrupteror?
Thanks
Jiffycoil, Wed Oct 17 2012, 05:10PM
Hi,
I was wondering if i could get the polyphonic code for the interrupteror?
Thanks
Re: oneTesla - a small single-board DRSSTC
Dr. ISOTOP, Wed Oct 17 2012, 09:15PM
PM me with your email address.
Dr. ISOTOP, Wed Oct 17 2012, 09:15PM
Jiffycoil wrote ...
Hi,
I was wondering if i could get the polyphonic code for the interrupteror?
Thanks
Hi,
I was wondering if i could get the polyphonic code for the interrupteror?
Thanks
PM me with your email address.
Re: oneTesla - a small single-board DRSSTC
E.TexasTesla, Fri Nov 02 2012, 12:52AM
Please help. Im having troubles with this 1 tesla board.
I wound the correct 2.5 x 10 inch secondary with 36 awg wire.
Im using the correct fets. And topload.
Secondary is grounded by 8 foot ground rod.
The only deviation from your schematic is the use of 74ls74n and 74ls14n
My gate transformer has 15 rounds on a toroid purchased from you I beleive.
Bus voltage is 336 volts.
My gate transformer is phased properly.
My interupter is Steve wards universal with fiber optic output.
The following pictures were taken at around 200 bps and around 20 us on time.
This first picture is from probe connected to outputs of ucc37321 and 322 (per step 3B in troubleshoot guide.)
The second picture is from Input to GDT after c8. 1u
On both GDT outputs the pattern is the same.
My question is could that initial (false ring) Be killing IGBT's ?
I have replaced c8 just to be sure but the pattern doesnt change.
I tried the full range of Steves interupter but the double pusle remains.
EDIT : I just realized one pulse is when the GDT is pulled high and the other is when its pulled low.
Right?
E.TexasTesla, Fri Nov 02 2012, 12:52AM
Please help. Im having troubles with this 1 tesla board.
I wound the correct 2.5 x 10 inch secondary with 36 awg wire.
Im using the correct fets. And topload.
Secondary is grounded by 8 foot ground rod.
The only deviation from your schematic is the use of 74ls74n and 74ls14n
My gate transformer has 15 rounds on a toroid purchased from you I beleive.
Bus voltage is 336 volts.
My gate transformer is phased properly.
My interupter is Steve wards universal with fiber optic output.
The following pictures were taken at around 200 bps and around 20 us on time.
This first picture is from probe connected to outputs of ucc37321 and 322 (per step 3B in troubleshoot guide.)
The second picture is from Input to GDT after c8. 1u
On both GDT outputs the pattern is the same.
My question is could that initial (false ring) Be killing IGBT's ?
I have replaced c8 just to be sure but the pattern doesnt change.
I tried the full range of Steves interupter but the double pusle remains.
EDIT : I just realized one pulse is when the GDT is pulled high and the other is when its pulled low.
Right?
Re: oneTesla - a small single-board DRSSTC
E.TexasTesla, Fri Nov 02 2012, 01:08AM
Sorry for double post. I couldnt edit in another picture.
This is a close up of GDT.
IGBT's were not installed at the time of the picture but when I put a new pair in the pattern remained.
E.TexasTesla, Fri Nov 02 2012, 01:08AM
Sorry for double post. I couldnt edit in another picture.
This is a close up of GDT.
IGBT's were not installed at the time of the picture but when I put a new pair in the pattern remained.
Re: oneTesla - a small single-board DRSSTC
Dr. ISOTOP, Fri Nov 02 2012, 06:10PM
With IGBT's installed, what does the G-E signal on each transistor look like?
Also, make sure you have the correct gate resistor values.
Dr. ISOTOP, Fri Nov 02 2012, 06:10PM
With IGBT's installed, what does the G-E signal on each transistor look like?
Also, make sure you have the correct gate resistor values.
Re: oneTesla - a small single-board DRSSTC
E.TexasTesla, Fri Nov 02 2012, 08:20PM
The second scope pattern is without igbits but it looked the same with new ones installed.
The scope probe was connected between Gate to source. Looked the same at both igbits.
I couldnt find 6.8 ohm resistors so I substituted 10 ohm ones. They are not wire wound type.
E.TexasTesla, Fri Nov 02 2012, 08:20PM
The second scope pattern is without igbits but it looked the same with new ones installed.
The scope probe was connected between Gate to source. Looked the same at both igbits.
I couldnt find 6.8 ohm resistors so I substituted 10 ohm ones. They are not wire wound type.
Re: oneTesla - a small single-board DRSSTC
Dr. ISOTOP, Fri Nov 02 2012, 08:54PM
What's the V/div on the second pic? If that's Vge and it's 5V/div, there's something wrong there...it should swing up to 15V.
Is your 15V rail actually 15V? Are pins 7 and 8 of the UCC chips at 15V? (did you accidentally install a 7805 in place of the 7815?)
Also, while it is not the cause of your symptoms, I would strongly recommend switching to 6.8 ohm gate resistors.
Dr. ISOTOP, Fri Nov 02 2012, 08:54PM
E.TexasTesla wrote ...
The second scope pattern is without igbits but it looked the same with new ones installed.
The scope probe was connected between Gate to source. Looked the same at both igbits.
I couldnt find 6.8 ohm resistors so I substituted 10 ohm ones. They are not wire wound type.
The second scope pattern is without igbits but it looked the same with new ones installed.
The scope probe was connected between Gate to source. Looked the same at both igbits.
I couldnt find 6.8 ohm resistors so I substituted 10 ohm ones. They are not wire wound type.
What's the V/div on the second pic? If that's Vge and it's 5V/div, there's something wrong there...it should swing up to 15V.
Is your 15V rail actually 15V? Are pins 7 and 8 of the UCC chips at 15V? (did you accidentally install a 7805 in place of the 7815?)
Also, while it is not the cause of your symptoms, I would strongly recommend switching to 6.8 ohm gate resistors.
Re: oneTesla - a small single-board DRSSTC
E.TexasTesla, Sun Nov 04 2012, 02:49PM
V/div was at 1 volt in the second picture. Rail to rail on uccs is 12v.
I appreciate your guys help, I realize you are busy with college and such.
One thing that would help me would be a simple fixed signal generator (interupt) schematic
And samples of scope patterns from gate transformer while using fixed interupt.
Mabe a dummy load for testing.
I still cant beleive Im the only one having this circuit kick my butt.
Thanks,
Chris.
E.TexasTesla, Sun Nov 04 2012, 02:49PM
V/div was at 1 volt in the second picture. Rail to rail on uccs is 12v.
I appreciate your guys help, I realize you are busy with college and such.
One thing that would help me would be a simple fixed signal generator (interupt) schematic
And samples of scope patterns from gate transformer while using fixed interupt.
Mabe a dummy load for testing.
I still cant beleive Im the only one having this circuit kick my butt.
Thanks,
Chris.
Re: oneTesla - a small single-board DRSSTC
Dr. ISOTOP, Sun Nov 04 2012, 07:02PM
Can you remove the GDT and scope the output of the UCC's? If the rail is 12V and the output is not 0-12V, you have dead driver chips.
Also, you really should be running a 15V regulator on the gate drive, not 12V - the transistors desaturate at 12V gate at 300A and tend to explode.
Dr. ISOTOP, Sun Nov 04 2012, 07:02PM
Can you remove the GDT and scope the output of the UCC's? If the rail is 12V and the output is not 0-12V, you have dead driver chips.
Also, you really should be running a 15V regulator on the gate drive, not 12V - the transistors desaturate at 12V gate at 300A and tend to explode.
Re: oneTesla - a small single-board DRSSTC
E.TexasTesla, Sun Nov 04 2012, 11:45PM
OK. I switched Vreg. to 7815. GDT removed for these scope pictures.
EDIT: Both scope probes were set on 10x for these pictures. My mistake.
Patterns are still the same but the voltages were incorrect. Each ucc output was 0 to 15v
Dual trace scope set on 1v divisions. Chan. one "ucc1" is on top.
Pattern taken from each UCC output to ground.
Ucc2 has a very narrow pulse . I beleive enable pin signal is clipping it to soon.
Second picture is from Ucc output to ucc output.
Third picture is from pin 2 of Ucc1 to ground .
When I adjust BPS and on time the time base changes but the voltages stay the same.
E.TexasTesla, Sun Nov 04 2012, 11:45PM
OK. I switched Vreg. to 7815. GDT removed for these scope pictures.
EDIT: Both scope probes were set on 10x for these pictures. My mistake.
Patterns are still the same but the voltages were incorrect. Each ucc output was 0 to 15v
Dual trace scope set on 1v divisions. Chan. one "ucc1" is on top.
Pattern taken from each UCC output to ground.
Ucc2 has a very narrow pulse . I beleive enable pin signal is clipping it to soon.
Second picture is from Ucc output to ucc output.
Third picture is from pin 2 of Ucc1 to ground .
When I adjust BPS and on time the time base changes but the voltages stay the same.
Re: oneTesla - a small single-board DRSSTC
Dr. ISOTOP, Mon Nov 05 2012, 12:56AM
Assuming your scope is in calibration and you didn't get your V/div wrong, you need new UCC's...the output should be 0-15V when unloaded.
Dr. ISOTOP, Mon Nov 05 2012, 12:56AM
E.TexasTesla wrote ...
OK. I switched Vreg. to 7815. GDT removed for these scope pictures.
Dual trace scope set on 1v divisions. Chan. one "ucc1" is on top.
Pattern taken from each UCC output to ground.
Aprox. 7 volts on each output with 15.2 v rail.
Ucc2 has a very narrow pulse . I beleive enable pin signal is clipping it to soon.
Second picture is from Ucc output to ucc output.
Its on 1v division and is at 15 volts peak to peak.
Third picture is from pin 2 of Ucc1 to ground . Looks very low. Aprox. 3 v swing.
Pin 3 from ucc 1 to ground has a steady square wav. I assume normal due to no current flow.
When I adjust BPS and on time the time base changes but the voltages stay the same.
OK. I switched Vreg. to 7815. GDT removed for these scope pictures.
Dual trace scope set on 1v divisions. Chan. one "ucc1" is on top.
Pattern taken from each UCC output to ground.
Aprox. 7 volts on each output with 15.2 v rail.
Ucc2 has a very narrow pulse . I beleive enable pin signal is clipping it to soon.
Second picture is from Ucc output to ucc output.
Its on 1v division and is at 15 volts peak to peak.
Third picture is from pin 2 of Ucc1 to ground . Looks very low. Aprox. 3 v swing.
Pin 3 from ucc 1 to ground has a steady square wav. I assume normal due to no current flow.
When I adjust BPS and on time the time base changes but the voltages stay the same.
Assuming your scope is in calibration and you didn't get your V/div wrong, you need new UCC's...the output should be 0-15V when unloaded.
Re: oneTesla - a small single-board DRSSTC
..., Mon Nov 05 2012, 01:07AM
Looks to me like the probe is set for 10x attenuation?
..., Mon Nov 05 2012, 01:07AM
Looks to me like the probe is set for 10x attenuation?
Re: oneTesla - a small single-board DRSSTC
E.TexasTesla, Mon Nov 05 2012, 04:17AM
Yes both probes were set x10.
E.TexasTesla, Mon Nov 05 2012, 04:17AM
Yes both probes were set x10.
Re: oneTesla - a small single-board DRSSTC
Dr. ISOTOP, Thu Nov 15 2012, 08:56AM
You can do a simple test by removing the current transformer and driving the CT pins with a 250KHz sine wave, while the interrupter is installed. If the signal at each IGBT gate is a reasonably nice 0-15V square-wave, then you can assume the signal pathway is intact and you did something silly on the power end of things.
Dr. ISOTOP, Thu Nov 15 2012, 08:56AM
You can do a simple test by removing the current transformer and driving the CT pins with a 250KHz sine wave, while the interrupter is installed. If the signal at each IGBT gate is a reasonably nice 0-15V square-wave, then you can assume the signal pathway is intact and you did something silly on the power end of things.
Re: oneTesla - a small single-board DRSSTC
Dr. ISOTOP, Sat Nov 17 2012, 12:38AM
...and, it turns out the coil was out of tune the whole time
here it is with a 2x8" spun toroid, slightly lower (!) on-times than before
Dr. ISOTOP, Sat Nov 17 2012, 12:38AM
...and, it turns out the coil was out of tune the whole time
here it is with a 2x8" spun toroid, slightly lower (!) on-times than before
Re: oneTesla - a small single-board DRSSTC
teravolt, Sat Nov 17 2012, 02:31AM
what do you think your primary current is?
teravolt, Sat Nov 17 2012, 02:31AM
what do you think your primary current is?
Re: oneTesla - a small single-board DRSSTC
Dr. ISOTOP, Sat Nov 17 2012, 10:18AM
Last I checked, it was around 300Apk
Dr. ISOTOP, Sat Nov 17 2012, 10:18AM
teravolt wrote ...
what do you think your primary current is?
what do you think your primary current is?
Last I checked, it was around 300Apk
Re: oneTesla - a small single-board DRSSTC
teravolt, Sat Nov 17 2012, 06:12PM
that is ia nice setup, is that little ciol working with your new board? have you thought of selling that coil in your last video as a kit.
teravolt, Sat Nov 17 2012, 06:12PM
that is ia nice setup, is that little ciol working with your new board? have you thought of selling that coil in your last video as a kit.
Re: oneTesla - a small single-board DRSSTC
Dr. ISOTOP, Sun Nov 18 2012, 04:22AM
For now, as usual, if you want a board you can PM me.
New pics
Dr. ISOTOP, Sun Nov 18 2012, 04:22AM
teravolt wrote ...
that is ia nice setup, is that little ciol working with your new board?
Yep, the new board adds a few little features such as a MIDI-signal-present indicator lamp and a fuse. It also tightens up the layout of the controller.that is ia nice setup, is that little ciol working with your new board?
teravolt wrote ...
have you thought of selling that coil in your last video as a kit.
This has been in the works for a while; expect to see kits for sale soon, complete with laser-cut acrylic components and (cheap) optional pre-wound secondary.have you thought of selling that coil in your last video as a kit.
For now, as usual, if you want a board you can PM me.
New pics
Re: oneTesla - a small single-board DRSSTC
Patrick, Sun Nov 18 2012, 04:27AM
Patrick, Sun Nov 18 2012, 04:27AM
Dr. ISOTOP wrote ...
really cool box!Re: oneTesla - a small single-board DRSSTC
E.TexasTesla, Sun Nov 18 2012, 07:46PM
Ok, with the CT out of the circuit and a 200 khz (my signal generator only goes up to 200khz)
signal substituted both my igbt gates are still not square. The signal going into the gate transformer is also not square.
I think im done with this circuit. It looks nice and I beleive you guys did a good job with it but Ive blown way to many parts and money.
As far as the board and traces go they are in poor shape. This pcb was not designed to handle any repairs.
Desoldering with the correct tool still pulls traces up.
E.TexasTesla, Sun Nov 18 2012, 07:46PM
Dr. ISOTOP wrote ...
You can do a simple test by removing the current transformer and driving the CT pins with a 250KHz sine wave, while the interrupter is installed. If the signal at each IGBT gate is a reasonably nice 0-15V square-wave, then you can assume the signal pathway is intact and you did something silly on the power end of things.
You can do a simple test by removing the current transformer and driving the CT pins with a 250KHz sine wave, while the interrupter is installed. If the signal at each IGBT gate is a reasonably nice 0-15V square-wave, then you can assume the signal pathway is intact and you did something silly on the power end of things.
Ok, with the CT out of the circuit and a 200 khz (my signal generator only goes up to 200khz)
signal substituted both my igbt gates are still not square. The signal going into the gate transformer is also not square.
I think im done with this circuit. It looks nice and I beleive you guys did a good job with it but Ive blown way to many parts and money.
As far as the board and traces go they are in poor shape. This pcb was not designed to handle any repairs.
Desoldering with the correct tool still pulls traces up.
Re: oneTesla - a small single-board DRSSTC
Dr. ISOTOP, Sun Nov 18 2012, 08:01PM
The IGBT's don't particularly enjoy being desoldered.
The IC's should be socketed; desoldering a 14-pin package is nearly impossible even with proper tools.
Dr. ISOTOP, Sun Nov 18 2012, 08:01PM
E.TexasTesla wrote ...
Ok, with the CT out of the circuit and a 200 khz (my signal generator only goes up to 200khz)
signal substituted both my igbt gates are still not square. The signal going into the gate transformer is also not square.
I think im done with this circuit. It looks nice and I beleive you guys did a good job with it but Ive blown way to many parts and money. If someone wants this for parts I will put it on ebay or trade for something.
As far as the board and traces go they are in poor shape. This pcb was not designed to handle any repairs.
Desoldering with the correct tool still pulls traces up.
Dr. ISOTOP wrote ...
You can do a simple test by removing the current transformer and driving the CT pins with a 250KHz sine wave, while the interrupter is installed. If the signal at each IGBT gate is a reasonably nice 0-15V square-wave, then you can assume the signal pathway is intact and you did something silly on the power end of things.
You can do a simple test by removing the current transformer and driving the CT pins with a 250KHz sine wave, while the interrupter is installed. If the signal at each IGBT gate is a reasonably nice 0-15V square-wave, then you can assume the signal pathway is intact and you did something silly on the power end of things.
Ok, with the CT out of the circuit and a 200 khz (my signal generator only goes up to 200khz)
signal substituted both my igbt gates are still not square. The signal going into the gate transformer is also not square.
I think im done with this circuit. It looks nice and I beleive you guys did a good job with it but Ive blown way to many parts and money. If someone wants this for parts I will put it on ebay or trade for something.
As far as the board and traces go they are in poor shape. This pcb was not designed to handle any repairs.
Desoldering with the correct tool still pulls traces up.
The IGBT's don't particularly enjoy being desoldered.
The IC's should be socketed; desoldering a 14-pin package is nearly impossible even with proper tools.
Re: oneTesla - a small single-board DRSSTC
Jazzman56, Mon Nov 19 2012, 12:59AM
Dr. Isotop
Sorry for the newbie question,
But will this kit be beginner friendly and how long until it's released?
Thanks,
jazzman
Jazzman56, Mon Nov 19 2012, 12:59AM
Dr. Isotop
Sorry for the newbie question,
But will this kit be beginner friendly and how long until it's released?
Thanks,
jazzman
Re: oneTesla - a small single-board DRSSTC
Dr. ISOTOP, Mon Nov 19 2012, 03:06AM
Dr. ISOTOP, Mon Nov 19 2012, 03:06AM
Jazzman56 wrote ...
Dr. Isotop
Sorry for the newbie question,
But will this kit be beginner friendly and how long until it's released?
Thanks,
jazzman
Our goal is to make it as beginner-friendly as possible; expect a launch in the next couple months.Dr. Isotop
Sorry for the newbie question,
But will this kit be beginner friendly and how long until it's released?
Thanks,
jazzman
Re: oneTesla - a small single-board DRSSTC
Staci, Thu Dec 06 2012, 03:12PM
That's a great design! I admire your work. I've recently started playing around with the FGH60N60SMD myself - amazing part. The only time I've killed one it was a deliberate effort in a test jig.
Staci, Thu Dec 06 2012, 03:12PM
That's a great design! I admire your work. I've recently started playing around with the FGH60N60SMD myself - amazing part. The only time I've killed one it was a deliberate effort in a test jig.
Re: oneTesla - a small single-board DRSSTC
HV Enthusiast, Thu Dec 06 2012, 07:15PM
Nice work on the new design! However, now you have to change your screen name to Dr. TO247!!! LOL
HV Enthusiast, Thu Dec 06 2012, 07:15PM
Nice work on the new design! However, now you have to change your screen name to Dr. TO247!!! LOL
Re: oneTesla - a small single-board DRSSTC
Dr. ISOTOP, Thu Dec 06 2012, 09:11PM
lol yeah, as much as I adore the ISOTOP package TO-247's are just so much cheaper
And thanks for the kind words!
Dr. ISOTOP, Thu Dec 06 2012, 09:11PM
EasternVoltageResearch wrote ...
Nice work on the new design! However, now you have to change your screen name to Dr. TO247!!! LOL
Nice work on the new design! However, now you have to change your screen name to Dr. TO247!!! LOL
lol yeah, as much as I adore the ISOTOP package TO-247's are just so much cheaper
And thanks for the kind words!
Re: oneTesla - a small single-board DRSSTC
Dr. ISOTOP, Mon Dec 10 2012, 11:53AM
An interesting phenomenon: ground strikes appear to propagate like lighting, with a leader starting from the ground and extending to meet the streamer from the coil. At least that's what my camera says...it could be a figment of my imagination, or possibly a camera artifact
Pic attached. The image on the left is ~30ms before the image on the right.
Dr. ISOTOP, Mon Dec 10 2012, 11:53AM
An interesting phenomenon: ground strikes appear to propagate like lighting, with a leader starting from the ground and extending to meet the streamer from the coil. At least that's what my camera says...it could be a figment of my imagination, or possibly a camera artifact
Pic attached. The image on the left is ~30ms before the image on the right.
Re: oneTesla - a small single-board DRSSTC
Dr. ISOTOP, Fri Dec 28 2012, 08:25AM
Update!
We've launched our Kickstarter campaign! You can contribute to the cause here.
Our web store is here.
Download the user manual, latest Eagle files, and polyphonic interrupter firmware (binaries and source) here.
Dr. ISOTOP, Fri Dec 28 2012, 08:25AM
Update!
We've launched our Kickstarter campaign! You can contribute to the cause here.
Our web store is here.
Download the user manual, latest Eagle files, and polyphonic interrupter firmware (binaries and source) here.
Re: oneTesla - a small single-board DRSSTC
joshua_, Fri Dec 28 2012, 08:45AM
cjtenny just told me about the Kickstarter campaign; I'd been looking at this thread every so often for a while, but never in much detail. Selling a reliable small DRSSTC is a pretty good accomplishment; the user's manual looks great. Great work, all around.
joshua_, Fri Dec 28 2012, 08:45AM
cjtenny just told me about the Kickstarter campaign; I'd been looking at this thread every so often for a while, but never in much detail. Selling a reliable small DRSSTC is a pretty good accomplishment; the user's manual looks great. Great work, all around.
Re: oneTesla - a small single-board DRSSTC
Steve Conner, Fri Dec 28 2012, 09:25AM
Did you add OCD yet?
Steve Conner, Fri Dec 28 2012, 09:25AM
Did you add OCD yet?
Re: oneTesla - a small single-board DRSSTC
Dr. ISOTOP, Fri Dec 28 2012, 11:28PM
Dr. ISOTOP, Fri Dec 28 2012, 11:28PM
Steve Conner wrote ...
Did you add OCD yet?
been thinking about it...on one hand, it's a handful of components that makes the coil a lot more reliable; on the other hand, I've yet to blow up the coil (and this includes a couple of runs where the interrupter latched up high because I didn't shield it).Did you add OCD yet?
Re: oneTesla - a small single-board DRSSTC
Steve Conner, Sat Dec 29 2012, 11:10AM
I think having OCD might make for a better user experience if you plan to sell a lot of the things to complete noobs through Kickstarter. Of course they can still blow it up by building the OCD circuit wrong.
Steve Conner, Sat Dec 29 2012, 11:10AM
I think having OCD might make for a better user experience if you plan to sell a lot of the things to complete noobs through Kickstarter. Of course they can still blow it up by building the OCD circuit wrong.
Re: oneTesla - a small single-board DRSSTC
mikeselectricstuff, Sat Dec 29 2012, 08:47PM
A few random comments (aside from the obvious safety & liability issues that could arise from selling a TC kit to the kickstarter demographic...)
The interruptor doesn't seem to have a power LED - for a battery powered unit an obvious ON indication would seem rather useful. Ditto an indication of MIDI data.
Lack of a manual pitch control and fire button to allow MIDI-less operation seems somewhat bit penny-pinching.
Running the AVR at 16MHz, and using a 7805 regulator is probably at least doubling your standby power draw from what it could be.
As there's no full schematic (yet?) in the guide, the power arrangements appear unclear - why is there a DC jack on the main unit ? Is the LV section powered seperately? if so I wonder how wise this is, as the DC power lead will be rather vulnerable to noise pickup and strikes.
If seperately powered, it appears that there is no visible indication of primary circuit power being on. If this is really the case I think this is a rather serious safety omission.
No mains filtering.. at all....?
$209 seems rather a low price to cover costs of parts, kitting, packaging and all the other hidden work - I doubt you'd have got many fewer takers at $249
mikeselectricstuff, Sat Dec 29 2012, 08:47PM
A few random comments (aside from the obvious safety & liability issues that could arise from selling a TC kit to the kickstarter demographic...)
The interruptor doesn't seem to have a power LED - for a battery powered unit an obvious ON indication would seem rather useful. Ditto an indication of MIDI data.
Lack of a manual pitch control and fire button to allow MIDI-less operation seems somewhat bit penny-pinching.
Running the AVR at 16MHz, and using a 7805 regulator is probably at least doubling your standby power draw from what it could be.
As there's no full schematic (yet?) in the guide, the power arrangements appear unclear - why is there a DC jack on the main unit ? Is the LV section powered seperately? if so I wonder how wise this is, as the DC power lead will be rather vulnerable to noise pickup and strikes.
If seperately powered, it appears that there is no visible indication of primary circuit power being on. If this is really the case I think this is a rather serious safety omission.
No mains filtering.. at all....?
$209 seems rather a low price to cover costs of parts, kitting, packaging and all the other hidden work - I doubt you'd have got many fewer takers at $249
Re: oneTesla - a small single-board DRSSTC
Dr. ISOTOP, Sat Dec 29 2012, 09:34PM
Thanks for the advice, Mike
The interrupter will have a LED's on it next time, I forgot to add them when sending out this revision. Ditto on the mains power indicator.
The LV section runs off a 19V adapter. Haven't had troubles with noise pickup so far.
I might add a mains filtering choke if I can make room on the board; sadly, the main source of trouble is going to be the fact that the secondary is grounded to mains ground, and there's not much I can do about that (hence why the manual says to float your laptop and unplug nearby electronics).
Dr. ISOTOP, Sat Dec 29 2012, 09:34PM
Thanks for the advice, Mike
The interrupter will have a LED's on it next time, I forgot to add them when sending out this revision. Ditto on the mains power indicator.
The LV section runs off a 19V adapter. Haven't had troubles with noise pickup so far.
I might add a mains filtering choke if I can make room on the board; sadly, the main source of trouble is going to be the fact that the secondary is grounded to mains ground, and there's not much I can do about that (hence why the manual says to float your laptop and unplug nearby electronics).
Re: oneTesla - a small single-board DRSSTC
mikeselectricstuff, Sat Dec 29 2012, 11:52PM
Another useful addition might be an audio input with preamp, e.g. for guitars etc.
mikeselectricstuff, Sat Dec 29 2012, 11:52PM
Another useful addition might be an audio input with preamp, e.g. for guitars etc.
Re: oneTesla - a small single-board DRSSTC
Jazzman56, Mon Dec 31 2012, 01:44AM
Dammit was checking this thread almost everyday and i missed the launch and the $209 early version :(
Ohh well better get saving :P
Thanks for releasing the KIT
Jazzman56, Mon Dec 31 2012, 01:44AM
Dammit was checking this thread almost everyday and i missed the launch and the $209 early version :(
Ohh well better get saving :P
Thanks for releasing the KIT
Re: oneTesla - a small single-board DRSSTC
Steve Conner, Mon Dec 31 2012, 12:05PM
Mike, if you were worried about noise issues with the DC input cord, you should probably be even more worried about a high-impedance, low-level analog audio input.
Steve Conner, Mon Dec 31 2012, 12:05PM
Mike, if you were worried about noise issues with the DC input cord, you should probably be even more worried about a high-impedance, low-level analog audio input.
Re: oneTesla - a small single-board DRSSTC
mikeselectricstuff, Mon Dec 31 2012, 02:22PM
mikeselectricstuff, Mon Dec 31 2012, 02:22PM
Steve Conner wrote ...
Mike, if you were worried about noise issues with the DC input cord, you should probably be even more worried about a high-impedance, low-level analog audio input.
Yes but the former is at the base of the coil, the latter is on the other end of a length of fibre so can be put far enough away.Mike, if you were worried about noise issues with the DC input cord, you should probably be even more worried about a high-impedance, low-level analog audio input.
Re: oneTesla - a small single-board DRSSTC
Steve Conner, Mon Dec 31 2012, 04:02PM
Good point, when I started writing that post, I didn't even notice that the system used a fibre optic link. It was advertised as a single-board system, so I assumed they put the interrupter on the same board as the power circuitry.
Steve Conner, Mon Dec 31 2012, 04:02PM
Good point, when I started writing that post, I didn't even notice that the system used a fibre optic link. It was advertised as a single-board system, so I assumed they put the interrupter on the same board as the power circuitry.
Re: oneTesla - a small single-board DRSSTC
HV Enthusiast, Sun Jan 06 2013, 05:05PM
Responded to your PM - PM Sent.
HV Enthusiast, Sun Jan 06 2013, 05:05PM
Responded to your PM - PM Sent.
Re: oneTesla - a small single-board DRSSTC
E.TexasTesla, Mon Jan 07 2013, 01:57AM
Hello, Im having a problem with the midi interrupter board.
Software "Polyphonic MIDI-based DRSSTC interrupter (Version 1.0)"on an atmega328p.
What should the signal look like going into pin two of the arduino? Its currently at 5v and drops down to 4.5 volts during keystroke. I dont think thats enough change for valid serial input to atmega.
Im using a yamaha psr-170 keyboard with midi out.
When I power up the interrupter board and play a note I get no output from the fiber optic transmitter.
I've checked for 5v from pot. indicating its set to max.My signal to pin 2 at arduino is nice and square.
I figured my midi signal was weak so I bypassed the 220 ohm resistor between midi input and 4n25.
This dropped the signal down to 4 volts during key stroke but still no output from arduino.
I figure my keyboard is old and the midi signal may not be compatable with the software.
By the way congats on the kickstart program. Looks good.
EDIT: I replaced the 4n25 with another one and now my signal swings from 5 volts to 3 during keystrokes.
E.TexasTesla, Mon Jan 07 2013, 01:57AM
Hello, Im having a problem with the midi interrupter board.
Software "Polyphonic MIDI-based DRSSTC interrupter (Version 1.0)"on an atmega328p.
What should the signal look like going into pin two of the arduino? Its currently at 5v and drops down to 4.5 volts during keystroke. I dont think thats enough change for valid serial input to atmega.
Im using a yamaha psr-170 keyboard with midi out.
When I power up the interrupter board and play a note I get no output from the fiber optic transmitter.
I've checked for 5v from pot. indicating its set to max.My signal to pin 2 at arduino is nice and square.
I figured my midi signal was weak so I bypassed the 220 ohm resistor between midi input and 4n25.
This dropped the signal down to 4 volts during key stroke but still no output from arduino.
I figure my keyboard is old and the midi signal may not be compatable with the software.
By the way congats on the kickstart program. Looks good.
EDIT: I replaced the 4n25 with another one and now my signal swings from 5 volts to 3 during keystrokes.
Re: oneTesla - a small single-board DRSSTC
Dr. ISOTOP, Mon Jan 07 2013, 02:04AM
Try flashing the latest interrupter firmware, found here. The old code had some unfortunate issues with note handling.
The manual and schematics are here
If you're flashing your own ATMega, you need to set the fuses properly; CKDIV8 needs to be off, and SUT_CKSEL should be EXTFSXTAL_16KCK_14CK_4MS1
Dr. ISOTOP, Mon Jan 07 2013, 02:04AM
Try flashing the latest interrupter firmware, found here. The old code had some unfortunate issues with note handling.
The manual and schematics are here
If you're flashing your own ATMega, you need to set the fuses properly; CKDIV8 needs to be off, and SUT_CKSEL should be EXTFSXTAL_16KCK_14CK_4MS1
Re: oneTesla - a small single-board DRSSTC
E.TexasTesla, Mon Jan 07 2013, 03:06AM
Tried new code still no luck.
Im using my atmega328p from from my uno board.
Can I change the fuse settings with uno or do I need to buy a new chip and use an ISP-Programmer ?
When you reopen your store website mabe I could buy a preprogrammed chip.
E.TexasTesla, Mon Jan 07 2013, 03:06AM
Tried new code still no luck.
Im using my atmega328p from from my uno board.
Can I change the fuse settings with uno or do I need to buy a new chip and use an ISP-Programmer ?
When you reopen your store website mabe I could buy a preprogrammed chip.
Re: oneTesla - a small single-board DRSSTC
Dr. ISOTOP, Mon Jan 07 2013, 05:27AM
I'll send you a preprogrammed ATMega.
I would advise getting a USB to MIDI adapter off Ebay for ~$5; these are known to work with the code. And if it works with the adapter and not your keyboard, then please do inform me so I can figure out what the bug is.
Dr. ISOTOP, Mon Jan 07 2013, 05:27AM
E.TexasTesla wrote ...
Tried new code still no luck.
Im using my atmega328p from from my uno board.
Can I change the fuse settings with uno or do I need to buy a new chip and use an ISP-Programmer ?
When you reopen your store website mabe I could buy a preprogrammed chip.
Tried new code still no luck.
Im using my atmega328p from from my uno board.
Can I change the fuse settings with uno or do I need to buy a new chip and use an ISP-Programmer ?
When you reopen your store website mabe I could buy a preprogrammed chip.
I'll send you a preprogrammed ATMega.
I would advise getting a USB to MIDI adapter off Ebay for ~$5; these are known to work with the code. And if it works with the adapter and not your keyboard, then please do inform me so I can figure out what the bug is.
Re: oneTesla - a small single-board DRSSTC
E.TexasTesla, Tue Feb 12 2013, 03:52AM
Quick question, Whats the max on time for the one tesla board.
Still interested in one of your midi chips if you offer is still good.
Thanks.
E.TexasTesla, Tue Feb 12 2013, 03:52AM
Quick question, Whats the max on time for the one tesla board.
Still interested in one of your midi chips if you offer is still good.
Thanks.
Re: oneTesla - a small single-board DRSSTC
Dr. ISOTOP, Tue Feb 12 2013, 08:31PM
I run 135uS max; no guarantees above that. You want to keep Ipk under 300A.
Dr. ISOTOP, Tue Feb 12 2013, 08:31PM
E.TexasTesla wrote ...
Quick question, Whats the max on time for the one tesla board.
I seem to blow fets around 200 uS.
Still interested in one of your midi chips if you offer is still good.
Thanks.
Quick question, Whats the max on time for the one tesla board.
I seem to blow fets around 200 uS.
Still interested in one of your midi chips if you offer is still good.
Thanks.
I run 135uS max; no guarantees above that. You want to keep Ipk under 300A.
Print this page