Interesting SSTC circuit
Wolfram, Fri Jun 15 2007, 05:08PMWhile browsing around, I found this:
Here's some of the relevant information in german:
The circuit is quite unlike any other SSTC circuit I've seen, and judging from the pictures it seems to work quite well.
I might try out the circuit if I have the time later today.
Here's a video on YouTube:
Re: Interesting SSTC circuit
Ken M., Fri Jun 15 2007, 05:57PM
WOW, thats the guy who has the 24v SSTC on youtube that puts out quiet a bit of power.
Edit whoops I didn't otice the link to youtube. LOL
Ken M., Fri Jun 15 2007, 05:57PM
WOW, thats the guy who has the 24v SSTC on youtube that puts out quiet a bit of power.
Edit whoops I didn't otice the link to youtube. LOL
Re: Interesting SSTC circuit
Wolfram, Fri Jun 15 2007, 08:13PM
I'm trying to understand the circuit now (MiniTesla 2). This is what I have come up with so far:
The 555 acts as an interrupter, along with R5, R6, R7, C8 and P1.
R8, R10, C10, Z2, T5 and T6 seem to be some sort of discrete voltage regulator. What does T5 do?
T4 turns the coil off by grounding the gates of both switching FETs through D3 and D4.
D4, D3 and D7 clamp the FET gate voltage to the voltage from the discrete regulator + 1.2V
D1, D2, Z1, R1, T1, C1-3 and C5 perform some sort of clamping on the MOSFET drain voltage, or?
The main power stage is a push-pull stage, and gate drive is provided from secondary base current through TR1.
R2, R3, D5, D6, D10-14 and C6 are there to bias the gates, right?
C4 and L4 form a parallel resonant circuit that helps the gate drive (?). The resonant frequency of this LC network has to be tuned to the Fres of the secondary.
Feel free to correct me and/or add to this theory.
Anders M.
Wolfram, Fri Jun 15 2007, 08:13PM
I'm trying to understand the circuit now (MiniTesla 2). This is what I have come up with so far:
The 555 acts as an interrupter, along with R5, R6, R7, C8 and P1.
R8, R10, C10, Z2, T5 and T6 seem to be some sort of discrete voltage regulator. What does T5 do?
T4 turns the coil off by grounding the gates of both switching FETs through D3 and D4.
D4, D3 and D7 clamp the FET gate voltage to the voltage from the discrete regulator + 1.2V
D1, D2, Z1, R1, T1, C1-3 and C5 perform some sort of clamping on the MOSFET drain voltage, or?
The main power stage is a push-pull stage, and gate drive is provided from secondary base current through TR1.
R2, R3, D5, D6, D10-14 and C6 are there to bias the gates, right?
C4 and L4 form a parallel resonant circuit that helps the gate drive (?). The resonant frequency of this LC network has to be tuned to the Fres of the secondary.
Feel free to correct me and/or add to this theory.
Anders M.
Re: Interesting SSTC circuit
Ken M., Fri Jun 15 2007, 09:24PM
I think T5 acts like a frequency or interuptor circuit, c10 charges then discharges through t5 and 6, charging c9.
Ken M., Fri Jun 15 2007, 09:24PM
I think T5 acts like a frequency or interuptor circuit, c10 charges then discharges through t5 and 6, charging c9.
Re: Interesting SSTC circuit
Coronafix, Fri Jun 15 2007, 10:35PM
Isn't it using a feedback coil to get the resonant frequency?
That's at first glance.
Coronafix, Fri Jun 15 2007, 10:35PM
Isn't it using a feedback coil to get the resonant frequency?
That's at first glance.
Re: Interesting SSTC circuit
Ken M., Sat Jun 16 2007, 02:08AM
Actually...yes I think its got maybe a current transformer that reads the secondaries frequency and feeds it straight into the 2 fets, this is of course through some kind of transformer, and then its fed to some to some other circuitry, at least thats the way it looks.
Ken M., Sat Jun 16 2007, 02:08AM
Actually...yes I think its got maybe a current transformer that reads the secondaries frequency and feeds it straight into the 2 fets, this is of course through some kind of transformer, and then its fed to some to some other circuitry, at least thats the way it looks.
Re: Interesting SSTC circuit
Coronafix, Sat Jun 16 2007, 02:47AM
I think the 555 serves to start the circuit and once it's running via it's own feedback in
push-pull operation, T5 and T6 hold the 555 off somehow.
C4 & L4 look like a grid leak tank.
I don't know a lot about electronics so forgive me if I'm way off.
Coronafix, Sat Jun 16 2007, 02:47AM
I think the 555 serves to start the circuit and once it's running via it's own feedback in
push-pull operation, T5 and T6 hold the 555 off somehow.
C4 & L4 look like a grid leak tank.
I don't know a lot about electronics so forgive me if I'm way off.
Re: Interesting SSTC circuit
Bennem, Sat Jun 16 2007, 06:07AM
Hi Anders M,
It was good to meet you at this years Nottingham Teslathon!
Yes...i too came across this guys web site a few months ago,
and i think you are correct in your circuit description.
I was going to try and make his 24 volt version,
but have not got around to it yet.
To make it operate off 24 v i was just going to put
a 7812 regulater instead of the zener and transistor he used.
But....his 12-24volt coils sparks are impressive for such low operating
input voltage....
Bennem, Sat Jun 16 2007, 06:07AM
Hi Anders M,
It was good to meet you at this years Nottingham Teslathon!
Yes...i too came across this guys web site a few months ago,
and i think you are correct in your circuit description.
I was going to try and make his 24 volt version,
but have not got around to it yet.
To make it operate off 24 v i was just going to put
a 7812 regulater instead of the zener and transistor he used.
But....his 12-24volt coils sparks are impressive for such low operating
input voltage....
Re: Interesting SSTC circuit
Coronafix, Sat Jun 16 2007, 11:09AM
I've become fascinated with this circuit, thanks for sharing Anders M.
The sparks he is getting are soooo impressive.
As I've said, I don't know a lot of electronics, everything I know I've taught myself over
the years, so if anyone (both Steve's?) can clarify what is going on here it would be much appreciated.
Is it just me or is that a novel way of using a bridge rectifier?
I have been looking to build my first SSTC for a while and had gathered
together some information as to what I can build, as in Australia we have 240V mains
and a distinct lack of the parts that you Yanks have, well we call them differently anyway.
This circuit though seems ultra simple in parts, I've got some FETs from an old UPS that will
work for this application out in the shed. No need for FET drivers or PLL chips or comparators.
Do you think this could be scaled to run at mains rectified voltage?
I have to be honest though that I haven't got my head around zeners yet, and their function. I have a feeling that Z2 plays a major part in switching off the 555 once the feedback kicks in. Is this correct?
Coronafix, Sat Jun 16 2007, 11:09AM
I've become fascinated with this circuit, thanks for sharing Anders M.
The sparks he is getting are soooo impressive.
As I've said, I don't know a lot of electronics, everything I know I've taught myself over
the years, so if anyone (both Steve's?) can clarify what is going on here it would be much appreciated.
Is it just me or is that a novel way of using a bridge rectifier?
I have been looking to build my first SSTC for a while and had gathered
together some information as to what I can build, as in Australia we have 240V mains
and a distinct lack of the parts that you Yanks have, well we call them differently anyway.
This circuit though seems ultra simple in parts, I've got some FETs from an old UPS that will
work for this application out in the shed. No need for FET drivers or PLL chips or comparators.
Do you think this could be scaled to run at mains rectified voltage?
I have to be honest though that I haven't got my head around zeners yet, and their function. I have a feeling that Z2 plays a major part in switching off the 555 once the feedback kicks in. Is this correct?
Re: Interesting SSTC circuit
Ken M., Sat Jun 16 2007, 01:35PM
Yes indeed, considering most of us who have built SSTC's only get the little corona haze or make a class E with 50v in or so, and yet this guy can run it as low as 18v and STILL get SG\DRSSTC arcs off the topload, I too will one day try this design but for now its off to finishing the big boy, considering I have all the drive electronics tested, the GDT running fine (I think and Hope).
Ken M., Sat Jun 16 2007, 01:35PM
Yes indeed, considering most of us who have built SSTC's only get the little corona haze or make a class E with 50v in or so, and yet this guy can run it as low as 18v and STILL get SG\DRSSTC arcs off the topload, I too will one day try this design but for now its off to finishing the big boy, considering I have all the drive electronics tested, the GDT running fine (I think and Hope).
Re: Interesting SSTC circuit
Steve Conner, Sat Jun 16 2007, 03:21PM
OK, here goes:
The 555 is just an interrupter, which shorts out the gate drive via T3.
R1 and R2 are what get the circuit started by turning one of the FETs on slightly, at which point it cranks itself up by positive feedback.
The MOSFET gates are driven directly off the current transformer. The huge mass of diodes 1, 2, 3, 4, 5, 8, 9, 10, 11, 12 serve to take the current transformer signal and clamp it to a safe value. D1, 2, 3 clamps it to a few diode drops above 13.5V and the remaining ones clamp it to 6 diode drops below ground. (Why he chose 6 diode drops, I have no idea. Maybe he got both MOSFETs turning on at once otherwise.) Anyway, it follows that if you want to use a higher supply voltage, you have to make sure the cathode of D3 still connects to 12V, so as not to lose the gate drive clamping action.
Since it uses the push-pull centre tapped circuit, he had to use a sizeable snubber, which in this case is made of D6, D7, C8, R6, R7.
As regards scaling up the voltage, Vladimiro Mazzilli made a similar circuit a while back, but using 1200V IGBTs and running off rectified 220V mains. It also was current-fed with a tuned primary, so the old pi*Vin thing applied. FETs from a UPS would probably be rated at no more than 60V.
Steve Conner, Sat Jun 16 2007, 03:21PM
OK, here goes:
The 555 is just an interrupter, which shorts out the gate drive via T3.
R1 and R2 are what get the circuit started by turning one of the FETs on slightly, at which point it cranks itself up by positive feedback.
The MOSFET gates are driven directly off the current transformer. The huge mass of diodes 1, 2, 3, 4, 5, 8, 9, 10, 11, 12 serve to take the current transformer signal and clamp it to a safe value. D1, 2, 3 clamps it to a few diode drops above 13.5V and the remaining ones clamp it to 6 diode drops below ground. (Why he chose 6 diode drops, I have no idea. Maybe he got both MOSFETs turning on at once otherwise.) Anyway, it follows that if you want to use a higher supply voltage, you have to make sure the cathode of D3 still connects to 12V, so as not to lose the gate drive clamping action.
Since it uses the push-pull centre tapped circuit, he had to use a sizeable snubber, which in this case is made of D6, D7, C8, R6, R7.
As regards scaling up the voltage, Vladimiro Mazzilli made a similar circuit a while back, but using 1200V IGBTs and running off rectified 220V mains. It also was current-fed with a tuned primary, so the old pi*Vin thing applied. FETs from a UPS would probably be rated at no more than 60V.
Re: Interesting SSTC circuit
Coronafix, Sat Jun 16 2007, 08:48PM
Thanks Steve, I was looking at the second link, his Skori Mini Tesla II.
He uses 60V 100A FETs, the UPS FETs I have are 55V 60A, so I figured they would do fine. I wasn't talking
about using them in a scaled up version, I'd have to start simple first.
Coronafix, Sat Jun 16 2007, 08:48PM
Thanks Steve, I was looking at the second link, his Skori Mini Tesla II.
He uses 60V 100A FETs, the UPS FETs I have are 55V 60A, so I figured they would do fine. I wasn't talking
about using them in a scaled up version, I'd have to start simple first.
Re: Interesting SSTC circuit
Mike, Sun Jun 17 2007, 09:48PM
really cool find. I spent a while talking with a hungarian person and translating the parts list. Here it is!
Resistors:
R1 330 ohm 1/2 watt metal layer resistor
R2 38 kohm 1/4 watt metal layer resistor
R3 80 kohm 1/4 watt metal layer resistor
R4 2.2 kohm 1/2 watt metal layer resistor
R5 22 kohm 1/2 watt metal layer resistor
R6 168 kohm 1/4 watt metal layer resistor
R7 168 kohm 1/4 watt metal layer resistor
R8 10 ohm 1/2 watt metal layer resistor
R9 5 ohm 2 watt metal layer resistor or wire
R10 2.2 kohm 1/2 watt metal layer resistor
P1 100 kohm linear potentiometer
Capacitors:
C1 2200uF 25V capacitor, low esr preferred
C2 2200uF 25V capacitor, low esr preferred
C3 6.8uF 63V Capacitor that tolerates impulses (MKS)
C4 7-15nF non-ceramic capacitor, value has to be determined experimentally
C5 100nF 100V Capacitor that tolerates impulses (MKS)
C6 100nF 63V Capacitor, not ceramic, pulse tolerant (MKS) preferred
C7 100nF 63V Capacitor, not ceramic, pulse tolerant (MKS) preferred
C8 22nF 63V Capacitor not ceramic
C9 1000uF 16V Capacitor
C10 22uF 16V Tantalum Capacitor
C11 2200uF 25V Capacitor, low esr preferred
Transformers:
TR1 30/15 windings (30 windings towards L3) cca. AL2000 iron core without air space | small ring-shaped iron core is recommended
Coils:
L1, L2: 1 winding? on 110mm diameter, thick coated wire, the wire of the two coils are twisted together or made of multi filar wire or an ?IDE cable? where every 2nd "circuit" is connected paralelly
L3: 1000-1800 winding? made of 0.1-0.2mm CuZ wire, rolled on a plastik tube with diameter=63mm
L4: 30-50uH 2A, value has to be determined in an experimental way, L4 C4 "resonating circuit?" has to resonate where L3 does (Tesla secunder)
Semiconductors:
T6 BUZZ11 or similar ( cheap) fet but one with much less current is enough (atleast 1A)
T1,T5 BD242c 3A 100v PNP or simmilar transistor (both on heatsink)
T2,T3 IRF3205 100A 55v N low channel mosfet or similar, but one with smaller current is not suitable
T4 BUZ11 50v 29A N channel mosfet or similar (IRFxxx etc) one under 20A is not practical because rds needs to be small/low
Z1 ZP51 51V- Zener Diode
Z2 ZPY15 15V-os zener Diode
D10-D14 1n4007 1A average Diode
D3-D7 1n5819 40V 1A schottkey Diode
D1,D2 SF18 600v 1a 35ns side by side
IC NE55 or compatible, the well known cheap 555 timer, but the cmos version (7555) is not suitable
Mike, Sun Jun 17 2007, 09:48PM
really cool find. I spent a while talking with a hungarian person and translating the parts list. Here it is!
Resistors:
R1 330 ohm 1/2 watt metal layer resistor
R2 38 kohm 1/4 watt metal layer resistor
R3 80 kohm 1/4 watt metal layer resistor
R4 2.2 kohm 1/2 watt metal layer resistor
R5 22 kohm 1/2 watt metal layer resistor
R6 168 kohm 1/4 watt metal layer resistor
R7 168 kohm 1/4 watt metal layer resistor
R8 10 ohm 1/2 watt metal layer resistor
R9 5 ohm 2 watt metal layer resistor or wire
R10 2.2 kohm 1/2 watt metal layer resistor
P1 100 kohm linear potentiometer
Capacitors:
C1 2200uF 25V capacitor, low esr preferred
C2 2200uF 25V capacitor, low esr preferred
C3 6.8uF 63V Capacitor that tolerates impulses (MKS)
C4 7-15nF non-ceramic capacitor, value has to be determined experimentally
C5 100nF 100V Capacitor that tolerates impulses (MKS)
C6 100nF 63V Capacitor, not ceramic, pulse tolerant (MKS) preferred
C7 100nF 63V Capacitor, not ceramic, pulse tolerant (MKS) preferred
C8 22nF 63V Capacitor not ceramic
C9 1000uF 16V Capacitor
C10 22uF 16V Tantalum Capacitor
C11 2200uF 25V Capacitor, low esr preferred
Transformers:
TR1 30/15 windings (30 windings towards L3) cca. AL2000 iron core without air space | small ring-shaped iron core is recommended
Coils:
L1, L2: 1 winding? on 110mm diameter, thick coated wire, the wire of the two coils are twisted together or made of multi filar wire or an ?IDE cable? where every 2nd "circuit" is connected paralelly
L3: 1000-1800 winding? made of 0.1-0.2mm CuZ wire, rolled on a plastik tube with diameter=63mm
L4: 30-50uH 2A, value has to be determined in an experimental way, L4 C4 "resonating circuit?" has to resonate where L3 does (Tesla secunder)
Semiconductors:
T6 BUZZ11 or similar ( cheap) fet but one with much less current is enough (atleast 1A)
T1,T5 BD242c 3A 100v PNP or simmilar transistor (both on heatsink)
T2,T3 IRF3205 100A 55v N low channel mosfet or similar, but one with smaller current is not suitable
T4 BUZ11 50v 29A N channel mosfet or similar (IRFxxx etc) one under 20A is not practical because rds needs to be small/low
Z1 ZP51 51V- Zener Diode
Z2 ZPY15 15V-os zener Diode
D10-D14 1n4007 1A average Diode
D3-D7 1n5819 40V 1A schottkey Diode
D1,D2 SF18 600v 1a 35ns side by side
IC NE55 or compatible, the well known cheap 555 timer, but the cmos version (7555) is not suitable
Re: Interesting SSTC circuit
Andrew L., Sun Jun 17 2007, 09:53PM
Wow that's great Mike
thanks.
Andrew L., Sun Jun 17 2007, 09:53PM
Wow that's great Mike
thanks.Re: Interesting SSTC circuit
Coronafix, Mon Jun 18 2007, 01:10AM
Thanks Mike, I spent a while myself with a Hungarian dictionary translating it.
Looking forward to building this.
Spent some time yesterday redrawing it in AutoCad as I couldn't print it from the web page.
Coronafix, Mon Jun 18 2007, 01:10AM
Thanks Mike, I spent a while myself with a Hungarian dictionary translating it.
Looking forward to building this.
Spent some time yesterday redrawing it in AutoCad as I couldn't print it from the web page.
Re: Interesting SSTC circuit
Coronafix, Mon Jun 18 2007, 10:10AM
Oops, here's the drawing.
] 1182161436_160_FT26972_skori_mini_tesla_ii_model_1 .pdf[/file]
Coronafix, Mon Jun 18 2007, 10:10AM
Oops, here's the drawing.
] 1182161436_160_FT26972_skori_mini_tesla_ii_model_1 .pdf[/file]
Re: Interesting SSTC circuit
Mike, Mon Jun 18 2007, 04:45PM
Very nice thanks goldsphere. Looks like we now have everything in english and able to print out to create it :D
Thanks
Mike, Mon Jun 18 2007, 04:45PM
Very nice thanks goldsphere. Looks like we now have everything in english and able to print out to create it :D
Thanks
Re: Interesting SSTC circuit
teravolt, Tue Jun 19 2007, 04:39AM
helo everybody I found this mosfet at digi-key IRFB3077PBF. 75v 210A what do you think
teravolt, Tue Jun 19 2007, 04:39AM
helo everybody I found this mosfet at digi-key IRFB3077PBF. 75v 210A what do you think
Re: Interesting SSTC circuit
teslaguy, Sat Jun 23 2007, 10:08PM
would this be a good coil for a beginner to build? I found most of the parts at digitkey and its in my price range.
teslaguy, Sat Jun 23 2007, 10:08PM
would this be a good coil for a beginner to build? I found most of the parts at digitkey and its in my price range.
Re: Interesting SSTC circuit
Part Scavenger, Sun Jun 24 2007, 03:11AM
HM2004:
I would go with this one here:
That is an extremely popular and tried SSTC design, Tons of people have built it and it's easy to put together and understand. Need any help, just post a thread, PM me or whomever/whatever. This is a good place to be for that sort of thing.
PS, 4HV's nice to noobies, but there's kinda a *thing* about hijacking threads...
Part Scavenger, Sun Jun 24 2007, 03:11AM
HM2004:
I would go with this one here:
That is an extremely popular and tried SSTC design, Tons of people have built it and it's easy to put together and understand. Need any help, just post a thread, PM me or whomever/whatever. This is a good place to be for that sort of thing.
PS, 4HV's nice to noobies, but there's kinda a *thing* about hijacking threads...
Re: Interesting SSTC circuit
Coronafix, Sun Jun 24 2007, 08:57AM
I actually think this one is better for a first SSTC beacause it doesn't need mains power
and the parts are simpler. As far as tried and tested, Steves mini is the way to go.
I'll let you know how it works once I've built it, if someone doesn't build it first.
Coronafix, Sun Jun 24 2007, 08:57AM
I actually think this one is better for a first SSTC beacause it doesn't need mains power
and the parts are simpler. As far as tried and tested, Steves mini is the way to go.
I'll let you know how it works once I've built it, if someone doesn't build it first.
Re: Interesting SSTC circuit
teravolt, Sun Jun 24 2007, 04:43PM
I have built the board and am wateing for FETs. It is a lot of work to go through for a measly 5" inches worth of spark so I am going to dubble up on the FETs IRFB3077PBF and input voltage in an efort to increase spark length. NB
teravolt, Sun Jun 24 2007, 04:43PM
I have built the board and am wateing for FETs. It is a lot of work to go through for a measly 5" inches worth of spark so I am going to dubble up on the FETs IRFB3077PBF and input voltage in an efort to increase spark length. NB
Re: Interesting SSTC circuit
Coronafix, Mon Jun 25 2007, 01:38AM
I had a look at those FETs teravolt, and they look good, cheaper than the suggested ones too.
I will also go with those ones, when I have time to build it. Kids suck time like you wouldn't believe!
Coronafix, Mon Jun 25 2007, 01:38AM
I had a look at those FETs teravolt, and they look good, cheaper than the suggested ones too.
I will also go with those ones, when I have time to build it. Kids suck time like you wouldn't believe!
Re: Interesting SSTC circuit
Ken M., Sun Sept 09 2007, 02:14PM
Just wondering, Does anyone or can any tell\guess what those batteries that he is using are rated for current wise? I pulled up the palma battery website but the have about 50 batteries on their 12v line and they range anywhere from .7ah to 230ah.
Ken M., Sun Sept 09 2007, 02:14PM
Just wondering, Does anyone or can any tell\guess what those batteries that he is using are rated for current wise? I pulled up the palma battery website but the have about 50 batteries on their 12v line and they range anywhere from .7ah to 230ah.
Re: Interesting SSTC circuit
uzzors2k, Sun Sept 09 2007, 05:58PM
The fets are rated for 55A, to give you a ballpark figure. I would just use an ATX PSU myself though.
uzzors2k, Sun Sept 09 2007, 05:58PM
The fets are rated for 55A, to give you a ballpark figure. I would just use an ATX PSU myself though.
Re: Interesting SSTC circuit
Ken M., Sun Sept 09 2007, 06:55PM
Thanks for the input Uzzors. Looking over some of this plus Mikes post with the parts, I noticed while watching the vid on WMP L1 and L2 is just a single layer of IDe cable and every other wire is connected in parallel, I guess to increase coupling or something.
Ken M., Sun Sept 09 2007, 06:55PM
Thanks for the input Uzzors. Looking over some of this plus Mikes post with the parts, I noticed while watching the vid on WMP L1 and L2 is just a single layer of IDe cable and every other wire is connected in parallel, I guess to increase coupling or something.
Re: Interesting SSTC circuit
Ken M., Thu Sept 20 2007, 04:10PM
Well folks I managed to build the skori, And its pretty interesting (no photos yet). Suliman the zener, fet, and Bjt makes an interesting voltage regulator, if you run the coil at 12v it gives the 555 part of the circuit a 8.56v supply and it stays at about 3.5v difference, untill about 15v input then the circuit taps out at 11.25v even when the input hits the 30v which was the max voltage my borrowed power supply could put out. As for who ever if anyone, wanted to know how he got good arcs for 12-24v its cuz its using the massive current capable puma battery's, the power supply I was using could only pump out about 2A at 24v, and I could only get maybe 1-2 thin arcs drawn to a nail I had in my hand and it was over currenting the supply, it was even weak enough, I could draw the arc to my fingers and it just felt like a fly was walking on my finger, although...My resonant L4,C4 circuit was based on a calculated value. All in all even with the current limitations I noticed that the circuit at 24V 2A could produce a visible corona around the primary.
Ken M., Thu Sept 20 2007, 04:10PM
Well folks I managed to build the skori, And its pretty interesting (no photos yet). Suliman the zener, fet, and Bjt makes an interesting voltage regulator, if you run the coil at 12v it gives the 555 part of the circuit a 8.56v supply and it stays at about 3.5v difference, untill about 15v input then the circuit taps out at 11.25v even when the input hits the 30v which was the max voltage my borrowed power supply could put out. As for who ever if anyone, wanted to know how he got good arcs for 12-24v its cuz its using the massive current capable puma battery's, the power supply I was using could only pump out about 2A at 24v, and I could only get maybe 1-2 thin arcs drawn to a nail I had in my hand and it was over currenting the supply, it was even weak enough, I could draw the arc to my fingers and it just felt like a fly was walking on my finger, although...My resonant L4,C4 circuit was based on a calculated value. All in all even with the current limitations I noticed that the circuit at 24V 2A could produce a visible corona around the primary.
Re: Interesting SSTC circuit
Tom540, Thu Sept 20 2007, 07:17PM
I wonder how hot those FETS get using those uber current capable batteries.
Tom540, Thu Sept 20 2007, 07:17PM
I wonder how hot those FETS get using those uber current capable batteries.
Re: Interesting SSTC circuit
uzzors2k, Fri Sept 21 2007, 02:18PM
Woops, the fets were 110A 55V. Which of the circuits did you use, WhiteArc? ATX PSUs can supply from 12 - 30A on the 12V line, don't have any lying around?
uzzors2k, Fri Sept 21 2007, 02:18PM
Woops, the fets were 110A 55V. Which of the circuits did you use, WhiteArc? ATX PSUs can supply from 12 - 30A on the 12V line, don't have any lying around?
Re: Interesting SSTC circuit
Ken M., Fri Sept 21 2007, 05:33PM
Nope, the ONLY working Atx aside from the ones in working pcs is the the 12v source for my larger coils 12v and 5v electronics. I used Mini coil 2 Also I did take 2 vids of the low current arcs.
(Hopefully the links work.)
Ken M., Fri Sept 21 2007, 05:33PM
Nope, the ONLY working Atx aside from the ones in working pcs is the the 12v source for my larger coils 12v and 5v electronics. I used Mini coil 2
Also I did take 2 vids of the low current arcs. (Hopefully the links work.)
Re: Interesting SSTC circuit
Ken M., Sun Sept 23 2007, 02:50AM
Well I was working on some stuff with the coil..and noticed that my positive wire was getting warm, so I disconnected all the gator wires, and connected the larger wire and now I've doubled the arc length, although now the heatsink for the fets gets hot fast. Got some pics and a vid.
Pics.
Ken M., Sun Sept 23 2007, 02:50AM
Well I was working on some stuff with the coil..and noticed that my positive wire was getting warm, so I disconnected all the gator wires, and connected the larger wire and now I've doubled the arc length, although now the heatsink for the fets gets hot fast. Got some pics and a vid.
Pics.
Re: Interesting SSTC circuit
a.gutzeit, Thu Nov 01 2007, 03:31PM
Hi,
I have decided to repeat Skory Mini Tesla Coil.
It is a really wonderful design.I have used Mini Tesla Coil v.3
schematics from
I have put separate DC power supplies for controlelectronics (15V from 12V/1.1A transformer) and
32V from 24V/5A transformer) for Primaries (through R2 resistor and
L1+L2 end).
My secondary is 75x200mm with 0.18mm wire. HV end of secondary is
connected with 5x100mm bronze sharp-pointed rod (screw).
(I have also tested 75x250x0.23 and 110x300x0.23 coils).
Primary (L1,L2) is 110mm diameter.
For TR1 I have used toroid 3E25 25x15x10mm with AL=5620()
(12x24 turns of 1.1mm enamel wire).
This Tesla transformer is easy produce 8-10cm (about 4")
sword-like streamers to air and 15-20cm arcs to ground (1hr working
time is not a problem)
Oscilloscope measurements, pictures and movies will be published in a
few days.
This coil is using only about 0.4-1.9A from 32V power supply depending of
interrupter frequency
Sincerely,
a.gutzeit
a.gutzeit, Thu Nov 01 2007, 03:31PM
Hi,
I have decided to repeat Skory Mini Tesla Coil.
It is a really wonderful design.I have used Mini Tesla Coil v.3
schematics from
I have put separate DC power supplies for controlelectronics (15V from 12V/1.1A transformer) and
32V from 24V/5A transformer) for Primaries (through R2 resistor and
L1+L2 end).
My secondary is 75x200mm with 0.18mm wire. HV end of secondary is
connected with 5x100mm bronze sharp-pointed rod (screw).
(I have also tested 75x250x0.23 and 110x300x0.23 coils).
Primary (L1,L2) is 110mm diameter.
For TR1 I have used toroid 3E25 25x15x10mm with AL=5620(
)(12x24 turns of 1.1mm enamel wire).
This Tesla transformer is easy produce 8-10cm (about 4")
sword-like streamers to air and 15-20cm arcs to ground (1hr working
time is not a problem)
Oscilloscope measurements, pictures and movies will be published in a
few days.
This coil is using only about 0.4-1.9A from 32V power supply depending of
interrupter frequency
Sincerely,
a.gutzeit
Re: Interesting SSTC circuit
Ken M., Fri Mar 28 2008, 10:44PM
I reaize that this topic is a bit dead but Incasesomeone was interested in doing this and was digging through the archives and found this topic, I figured I'd link a translated web page.
Ken M., Fri Mar 28 2008, 10:44PM
I reaize that this topic is a bit dead but Incasesomeone was interested in doing this and was digging through the archives and found this topic, I figured I'd link a translated web page.
Re: Interesting SSTC circuit
Ultra7, Sat Mar 29 2008, 04:10AM
thanks Ken, I was preening the forums, and this is what I was looking for.
Ultra7, Sat Mar 29 2008, 04:10AM
thanks Ken, I was preening the forums, and this is what I was looking for.
Re: Interesting SSTC circuit
Richardas, Thu Jan 07 2016, 05:21PM
I saw nothing about reviving dead posts in the forum rules, so here it is:
Few years ago I have studied the schematics of Skory ISSTC and a bit *improved it (*changed to my needs). Somehow I have lost the values of the components, but the schematic and video of operation is here .
The most interesting thing is that it started working from 12V and was consuming only 100mA, so it is quite efficient. Later by increasing supply voltage the length of the sparks increased until it reached 20V, by further increasing the supply voltage output sparks remained the same, but current consumption increased drastically well above 7A if interrupter was set to 80% duty cycle.
In the schematics I changed the snubber (R1, Z1, R8) to "softer" and simpler one, since the original one failed with smokes at 18V (because of low primary coil coupling), also added a pot to change duty cycle of interrupter and improvised better and cheaper power supply (voltage regulator) for 555 timer.
If anyone still gets interest in this ISSTC design let me know, I can add more info about my variation and explain more about the original circuit and its operation if anyone needs it.
Now I'm going to try to improve it further by making it more compact, increasing it's efficiency and lowering supply voltage even further. My goal is to make it run stable from 12V on constant (no interrupter) mode and staying under 2A with maximum possible output stremers, so that I could make it portable using 3 Li-Ion cells in series.
Further I'm going to make a proper digital interrupter controlled via PC terminal program or using a dedicated MCU to enable it play music in MIDI files or from standard 3.5 mm audio jack.
All my achievements and fails I'm going to post here if no one minds it.
Richardas, Thu Jan 07 2016, 05:21PM
I saw nothing about reviving dead posts in the forum rules, so here it is:
Few years ago I have studied the schematics of Skory ISSTC and a bit *improved it (*changed to my needs). Somehow I have lost the values of the components, but the schematic and video of operation is here
. The most interesting thing is that it started working from 12V and was consuming only 100mA, so it is quite efficient. Later by increasing supply voltage the length of the sparks increased until it reached 20V, by further increasing the supply voltage output sparks remained the same, but current consumption increased drastically well above 7A if interrupter was set to 80% duty cycle.
In the schematics I changed the snubber (R1, Z1, R8) to "softer" and simpler one, since the original one failed with smokes at 18V (because of low primary coil coupling), also added a pot to change duty cycle of interrupter and improvised better and cheaper power supply (voltage regulator) for 555 timer.
If anyone still gets interest in this ISSTC design let me know, I can add more info about my variation and explain more about the original circuit and its operation if anyone needs it.
Now I'm going to try to improve it further by making it more compact, increasing it's efficiency and lowering supply voltage even further. My goal is to make it run stable from 12V on constant (no interrupter) mode and staying under 2A with maximum possible output stremers, so that I could make it portable using 3 Li-Ion cells in series.
Further I'm going to make a proper digital interrupter controlled via PC terminal program or using a dedicated MCU to enable it play music in MIDI files or from standard 3.5 mm audio jack.
All my achievements and fails I'm going to post here if no one minds it.
Re: Interesting SSTC circuit
jdub1581hv, Thu Jan 07 2016, 06:34PM
Wouldn't it be easier to use LIPO's?
A couple 18v Cordless drill batteries in parallel..?
I'd think that would increase your sparks quite a bit..
jdub1581hv, Thu Jan 07 2016, 06:34PM
Wouldn't it be easier to use LIPO's?
A couple 18v Cordless drill batteries in parallel..?
I'd think that would increase your sparks quite a bit..
Re: Interesting SSTC circuit
Richardas, Fri Jan 08 2016, 09:31PM
Well, LiPos are better to handle more current, but I already have few LiIon batteries on hand and speaking about drill batteries – they are too big for what I'm going to make, since everything is going to be done using SMD parts. And the goal is to make it super stable and as efficient as possible, since last time it was good on 100mA, I see no need for massive batteries, but the sparks needs to be improved, while still using little power.
Already ordered few super nice MOSFETs for my driver:
They are awesome, imagine 1450A pulsed current, technologies are going far! I think should work perfect with a nice thick primary, good capacitor bank and a high current traces. Though a bit worried about input capacitance, it's freaking 12nF... But if I maintain resonant frequency low enough it would be still good, I hope... And also going to improve the MOSFET driving part for more current and faster switching, to cope with high gate capacity of the FETS.
Richardas, Fri Jan 08 2016, 09:31PM
Well, LiPos are better to handle more current, but I already have few LiIon batteries on hand and speaking about drill batteries – they are too big for what I'm going to make, since everything is going to be done using SMD parts. And the goal is to make it super stable and as efficient as possible, since last time it was good on 100mA, I see no need for massive batteries, but the sparks needs to be improved, while still using little power.
Already ordered few super nice MOSFETs for my driver:
They are awesome, imagine 1450A pulsed current, technologies are going far! I think should work perfect with a nice thick primary, good capacitor bank and a high current traces. Though a bit worried about input capacitance, it's freaking 12nF... But if I maintain resonant frequency low enough it would be still good, I hope... And also going to improve the MOSFET driving part for more current and faster switching, to cope with high gate capacity of the FETS.
Re: Interesting SSTC circuit
Dédé!, Wed Jan 20 2016, 03:08PM
Could you use this schematic, but modify it a little bit so it uses an H-bridge of N-channel and P-channel mosfets which is driven directly by primary current feedback, which drives a single coil with a tank capacitor so you'll have like a drsstc variant of this circuit?
Dédé!, Wed Jan 20 2016, 03:08PM
Could you use this schematic, but modify it a little bit so it uses an H-bridge of N-channel and P-channel mosfets which is driven directly by primary current feedback, which drives a single coil with a tank capacitor so you'll have like a drsstc variant of this circuit?
Re: Interesting SSTC circuit
paralaxx, Wed Jan 20 2016, 03:57PM
Hello , also collected SSTC 2n2222 on the small size for the experiments , the circuit on the video .
I noticed an interesting effect , which is found by chance during experiments with the coil .
At presentation to the minus contact oscilloscope ( but not touching ) to the (+ ) power supply terminal SSTC, the latter will consume 10 times less consumption instead of 60 mA becomes 6mA .
Video of the sstc Video effect described here
paralaxx, Wed Jan 20 2016, 03:57PM
Hello , also collected SSTC 2n2222 on the small size for the experiments , the circuit on the video .
I noticed an interesting effect , which is found by chance during experiments with the coil .
At presentation to the minus contact oscilloscope ( but not touching ) to the (+ ) power supply terminal SSTC, the latter will consume 10 times less consumption instead of 60 mA becomes 6mA .
Video of the sstc
Video effect described here Re: Interesting SSTC circuit
Dédé!, Sat Jan 23 2016, 05:03PM
I'm trying to create a drsstc version of this circuit.
That's why here is a schematic I came up with to add zero current crossing detection to the interrupter without adding another transformer and with the ability to detect the zero crossing whether it's a falling edge or a rising edge.
The circuit is drawn a little bit messily and the resistorvalues are chosen fairly arbitrarily.
V3 represents the secondary of the current transformer.
V4 represents the signal generator part of the interrupter
V(n014) is the waveform that's achieved when the clipped voltage of the current transformer is processed by an opamp.
V(n010) is the output of my zero crossing detection circuit.
V(n007) is the original interrupter signal
V(n009) is the output interrupter signal, which is achieved by putting V(n010) on the enable input of a NAND D-Flipflop and V(n007) on the D input.
I was wondering why it is that the output signal changes just a tiny bit before V(n010) goes high.
Is this just an inaccuracy of LTSice or is something different happening?
I know a few other things about the circuit will have to change to create a DRSSTC like this, but it's got to be possible. OCD isn't gonna be in the (first itteration of) this circuit.
Dédé!, Sat Jan 23 2016, 05:03PM
I'm trying to create a drsstc version of this circuit.
That's why here is a schematic I came up with to add zero current crossing detection to the interrupter without adding another transformer and with the ability to detect the zero crossing whether it's a falling edge or a rising edge.
The circuit is drawn a little bit messily and the resistorvalues are chosen fairly arbitrarily.
V3 represents the secondary of the current transformer.
V4 represents the signal generator part of the interrupter
V(n014) is the waveform that's achieved when the clipped voltage of the current transformer is processed by an opamp.
V(n010) is the output of my zero crossing detection circuit.
V(n007) is the original interrupter signal
V(n009) is the output interrupter signal, which is achieved by putting V(n010) on the enable input of a NAND D-Flipflop and V(n007) on the D input.
I was wondering why it is that the output signal changes just a tiny bit before V(n010) goes high.
Is this just an inaccuracy of LTSice or is something different happening?
I know a few other things about the circuit will have to change to create a DRSSTC like this, but it's got to be possible. OCD isn't gonna be in the (first itteration of) this circuit.
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