Teslathon DRSSTC (6) First Light!!
Reaching, Wed Jun 07 2006, 08:52PMwithin the next few weeks i want to build a nice powerful drsstc for the first ctc-labs teslathon in germany. i want it to be special and powerful for demonstrations etc.
within 3 days i made the primary and the case out of 8mm acrylic glas.
the primary coil consists out of 7 turns 6mm copper tubing.
for the mmc i have 36 wima mkp10 0,22yf 1600volt lying around, and a fullbridge of 40n60´s already finished.
driver with overcurrent protection, overvoltage protection, etc, primary current feedback .(not finished, i need some time for the pcb)
i thought about a secondary with ca 11cm in diameter and 50cm in height, wound with 0,2mm or so for a fres of around 100khz
here are two pics
the drsstc has to be finished and working until 28.07.06 , thats a possible goal
Update 12.06.06
i finished breadboarding the driver and the overcurrent protection and made 2 nice pcbs which are nearly finished.
the mmc is finished and consists out of 25 wima mkp10 0,22yf 1600 volts for a total of 220nF 8kV dc, 3,2kv AC.
Update!__________________-
first Light on 18.06.06
i finished the whole coil and the electronics and did some testruns today, with realy good results.
heres the finished coil without toroid, i have to make a nice one
and heres a pic of the first testrun on resonant frequency or almost in tune, . the sat antenna is 1,1m away, not bad for the first testrun.
Re: Teslathon DRSSTC (6) First Light!!
Reaching, Sat Jun 17 2006, 08:11AM
some new infos. the last two days i was working excessively on my coil to get it to work and yesterday i made the first tests with a other secondary to try the primary current feedback out. first i had trouble with a way too high frequency but i solved the problem by reversing the wire direction on the 1:140 feedback CT. but this thing will not work properly on primary current, dont know why, so i made the first light tests with secondary bottom feedback which worked fine. the overcurrent protection does not work properly but i think with a bit of time i will get it to work.
the whole acrylic base is full of electronics
heres a pic of the electronics
updates will come soon, today i want to debug the overcurrent protection to make it work, then i´ll try to get the primary current to work properly. the driver begins to oscillate at around 10volt but i get nearly no output when running on primary current feedback, maybe reversing the primary will help?
Reaching, Sat Jun 17 2006, 08:11AM
some new infos. the last two days i was working excessively on my coil to get it to work and yesterday i made the first tests with a other secondary to try the primary current feedback out. first i had trouble with a way too high frequency but i solved the problem by reversing the wire direction on the 1:140 feedback CT. but this thing will not work properly on primary current, dont know why, so i made the first light tests with secondary bottom feedback which worked fine. the overcurrent protection does not work properly but i think with a bit of time i will get it to work.
the whole acrylic base is full of electronics
heres a pic of the electronics
updates will come soon, today i want to debug the overcurrent protection to make it work, then i´ll try to get the primary current to work properly. the driver begins to oscillate at around 10volt but i get nearly no output when running on primary current feedback, maybe reversing the primary will help?
Re: Teslathon DRSSTC (6) First Light!!
Steve Ward, Sat Jun 17 2006, 08:25AM
Tuning is much more critical with primary feedback. Unlike secondary feedback, if its not pretty close to in tune, it wont do a whole lot but ring up the primary current really high.
Also, if its oscillating in the right frequency range (and not way too high) then the phasing is correct. reversing the primary connections does not alter the phasing with primary feedback. You are really sensing the current from the inverter, so you need to either swap the CT wires, or feed the CT primary through the other way, or invert your gate drive signal... If you dont see a distinct difference in oscillation behavior when you seemed to have switch the phasing, then you really didnt do anything (this got me once, when i tried swapping the TC primary connections with no change... i then realized why).
Steve Ward, Sat Jun 17 2006, 08:25AM
the driver begins to oscillate at around 10volt but i get nearly no output when running on primary current feedback, maybe reversing the primary will help?
Tuning is much more critical with primary feedback. Unlike secondary feedback, if its not pretty close to in tune, it wont do a whole lot but ring up the primary current really high.
Also, if its oscillating in the right frequency range (and not way too high) then the phasing is correct. reversing the primary connections does not alter the phasing with primary feedback. You are really sensing the current from the inverter, so you need to either swap the CT wires, or feed the CT primary through the other way, or invert your gate drive signal... If you dont see a distinct difference in oscillation behavior when you seemed to have switch the phasing, then you really didnt do anything (this got me once, when i tried swapping the TC primary connections with no change... i then realized why).
Re: Teslathon DRSSTC (6) First Light!!
Reaching, Sat Jun 17 2006, 08:57AM
mhh, okay, then it seems its all right, i get the right frequency, around 100 to 120khz with my primary circuit, 0,22yf 8kv cap and a 7 turn primary with an diamter of 24cm.
i changed back to primary current feedback and added a 1k resistor to the input of the 74hc00, now it seems to start oscillating at around 6 volt on the bridge. i made a scopeshot, looks like its fine but this is my first coil with primary current feedback so maybe someone tell me different.
heres the pic
measured without secondary in place, only primary circuit,. probes on primary, bridge voltage 6volt.
div 20v/cm 20yS/cm
current draw was 1A off time 0,35mS on time 140yS (i set the off time so high, otherwise i cant make a good scopeshot, its not the newest oscilloscope)
if i vary the on time by watching the scope the frequency locks perfectly in so i think it only switches on zero current, .
okay, measured the primary current with an calibrated 1/1000 CT
same settings as above ,6volt bridge voltage, div 50yS/cm 0,2v/cm
so what do you think, am i fine or not.
Reaching, Sat Jun 17 2006, 08:57AM
mhh, okay, then it seems its all right, i get the right frequency, around 100 to 120khz with my primary circuit, 0,22yf 8kv cap and a 7 turn primary with an diamter of 24cm.
i changed back to primary current feedback and added a 1k resistor to the input of the 74hc00, now it seems to start oscillating at around 6 volt on the bridge. i made a scopeshot, looks like its fine but this is my first coil with primary current feedback so maybe someone tell me different.
heres the pic
measured without secondary in place, only primary circuit,. probes on primary, bridge voltage 6volt.
div 20v/cm 20yS/cm
current draw was 1A off time 0,35mS on time 140yS (i set the off time so high, otherwise i cant make a good scopeshot, its not the newest oscilloscope)
if i vary the on time by watching the scope the frequency locks perfectly in so i think it only switches on zero current, .
okay, measured the primary current with an calibrated 1/1000 CT
same settings as above ,6volt bridge voltage, div 50yS/cm 0,2v/cm
so what do you think, am i fine or not.
Re: Teslathon DRSSTC (6) First Light!!
Steve Ward, Sat Jun 17 2006, 05:08PM
Can you zoom in on the scope to show only 1-2 cycles of the CT output? Id like to see where the switching noise is. Zoom in on some of the last few cycles. It looks fine so far as i can tell (though your scope is pretty out of focus!).
Steve Ward, Sat Jun 17 2006, 05:08PM
Can you zoom in on the scope to show only 1-2 cycles of the CT output? Id like to see where the switching noise is. Zoom in on some of the last few cycles. It looks fine so far as i can tell (though your scope is pretty out of focus!).
Re: Teslathon DRSSTC (6) First Light!!
Reaching, Sat Jun 17 2006, 06:04PM
hehe, yeah youre right, my scope is 22years old and has several bad contacts inside i think, expecially on the focus and trigger pots.though its hard to calibrate and to make pics from it, but from time to time it works ,
heres a pic of the last few cycles, 20v/div 20yS/div , bridge voltage 12 volt
i can show some pics of the current waveforms on the ct when my overcurrent protection pcb is finished, hope its all right,
and steve, its not your circuit so you cant compare it with your settings, the basics are the same, 74hc14,74hc109, but i use a 74hc00 for the set and reset of the 74hc109
Reaching, Sat Jun 17 2006, 06:04PM
hehe, yeah youre right, my scope is 22years old and has several bad contacts inside i think, expecially on the focus and trigger pots.though its hard to calibrate and to make pics from it, but from time to time it works ,
heres a pic of the last few cycles, 20v/div 20yS/div , bridge voltage 12 volt
i can show some pics of the current waveforms on the ct when my overcurrent protection pcb is finished, hope its all right,
and steve, its not your circuit so you cant compare it with your settings, the basics are the same, 74hc14,74hc109, but i use a 74hc00 for the set and reset of the 74hc109
Re: Teslathon DRSSTC (6) First Light!!
Steve Ward, Sat Jun 17 2006, 07:36PM
Ok, so what is that waveform you just posted? Was it from a CT? Or was it some voltage somewhere?
If its from the CT, them im mighty confused, because the switching noise seen would suggest that you are switching *before* the zero crossing, which would mean that somehow your driver can predict when the zero crossing would occur (though, its not very good at it).
Steve Ward, Sat Jun 17 2006, 07:36PM
Ok, so what is that waveform you just posted? Was it from a CT? Or was it some voltage somewhere?
If its from the CT, them im mighty confused, because the switching noise seen would suggest that you are switching *before* the zero crossing, which would mean that somehow your driver can predict when the zero crossing would occur (though, its not very good at it).
Re: Teslathon DRSSTC (6) First Light!!
Reaching, Sat Jun 17 2006, 08:56PM
the waveform is meaured at the primary with a bridge supply voltage of 12volts. i have to finish the overcurrent protection circuit, then i can make a few signal pics of the 1/1000 current CT and the 1/140 current transformer.give me a few hours
mhh, okay, it was the best i could do, my scope is to old to trigger properly so i had to trigger by hand, measured on the 1/1000 current transformer with 10R burden resistor in place. 0,1v/div 50yS/div
Reaching, Sat Jun 17 2006, 08:56PM
the waveform is meaured at the primary with a bridge supply voltage of 12volts. i have to finish the overcurrent protection circuit, then i can make a few signal pics of the 1/1000 current CT and the 1/140 current transformer.give me a few hours
mhh, okay, it was the best i could do, my scope is to old to trigger properly so i had to trigger by hand, measured on the 1/1000 current transformer with 10R burden resistor in place. 0,1v/div 50yS/div
Re: Teslathon DRSSTC (6) First Light!!
Hazmatt_(The Underdog), Sat Jun 17 2006, 09:33PM
Teach yourself how to flame polish the plexi and hearts will stop when they see it!
I do it with a small flame from my prop/oxy rig..but CR does it with a propane torch I think.
Hazmatt_(The Underdog), Sat Jun 17 2006, 09:33PM
Teach yourself how to flame polish the plexi and hearts will stop when they see it!
I do it with a small flame from my prop/oxy rig..but CR does it with a propane torch I think.
Re: Teslathon DRSSTC (6) First Light!!
Reaching, Sun Jun 18 2006, 01:28PM
hehe, good idea, i have some small pieces of the plexi liying around so i´ll try it.
new Update, finished the secondary,
looks nice and heavy
hrhr, first light today!!!!
i couldnt wait to test this monster and wired it together, the secondary is almost dry, lol,,. okay i set the on time to around 80ys , overcurrent protection for testing to 300A, looks good so far, around 70cm discharges in the wall, i have to build it upt in my testing room where i have more space for testing.. never thought that a primary feedback drsstc is so hard to adjust. i had to raise the secondary around 5cm to prevent racing arcs, maybe to high coupling or so.
heres a video of the first test, sorry its in german i cant speak english that good
so i think everything is fine, needs a bit more tuning and more space for testing and a nicer toroid, *happy*
update__________________-
hrhr, forget the video, look at this pic,, the sat antenna is 1,1meter away , i played around with the coupling and the primary frequency until i got it, its not finetuned yet, maximum current setting is 350A , on time ca 100yS nothing more, thats a real monster
Reaching, Sun Jun 18 2006, 01:28PM
hehe, good idea, i have some small pieces of the plexi liying around so i´ll try it.
new Update, finished the secondary,
looks nice and heavy
hrhr, first light today!!!!
i couldnt wait to test this monster and wired it together, the secondary is almost dry, lol,,. okay i set the on time to around 80ys , overcurrent protection for testing to 300A, looks good so far, around 70cm discharges in the wall, i have to build it upt in my testing room where i have more space for testing.. never thought that a primary feedback drsstc is so hard to adjust. i had to raise the secondary around 5cm to prevent racing arcs, maybe to high coupling or so.
heres a video of the first test, sorry its in german i cant speak english that good
so i think everything is fine, needs a bit more tuning and more space for testing and a nicer toroid,
*happy*update__________________-
hrhr, forget the video, look at this pic,, the sat antenna is 1,1meter away , i played around with the coupling and the primary frequency until i got it, its not finetuned yet, maximum current setting is 350A , on time ca 100yS nothing more, thats a real monster
Re: Teslathon DRSSTC (6) First Light!!
Reaching, Tue Jun 20 2006, 06:22PM
okay, i played a bit with the tuning, but not too much cause i need a nicer toroid for the final version. today i made a few pics, i wonder that i get the best results with a on time of around 100ys,
distance in the first pic is 1 meter or 40",in the second pic 1,15meter or 46" not to bad
heres a pic of the whole thing
exposure time in all pics is 6 seconds with the short light on,off trick to lighten the background
Reaching, Tue Jun 20 2006, 06:22PM
okay, i played a bit with the tuning, but not too much cause i need a nicer toroid for the final version. today i made a few pics, i wonder that i get the best results with a on time of around 100ys,
distance in the first pic is 1 meter or 40",in the second pic 1,15meter or 46" not to bad
heres a pic of the whole thing
exposure time in all pics is 6 seconds with the short light on,off trick to lighten the background
Re: Teslathon DRSSTC (6) First Light!!
Reaching, Fri Jun 23 2006, 08:22PM
21.06.06
started building the toroid, i buyed some plywood, alu ducting pipe and some polyester kitt (to fill the nasty holes in the alu ducting pipe)
22.06.06
started sanding the surface
23.06.06
finish with aluminium tape, pics soon
the new toroid is 10x42cm
heres the nearly finished toroid
mhh, okay, now i have a problem, mh not a real problem, i get only about twice the discharge lenght of my secondary, but i know from my other drsstcs that i can get much more. the new toroid is finished and as i calculated i reduced the frequency to around 90khz i had to attach the primary to around 5,3 turns, . i tinkled with the on and off times and the funniest is that i get the longest streamers with a on time of around 80yS , more on time makes them shorter. mhh three weeks of building and now a dissapointing result?
mhh, heres a pic of the discharges at resonant frequency
Reaching, Fri Jun 23 2006, 08:22PM
21.06.06
started building the toroid, i buyed some plywood, alu ducting pipe and some polyester kitt (to fill the nasty holes in the alu ducting pipe)
22.06.06
started sanding the surface
23.06.06
finish with aluminium tape, pics soon
the new toroid is 10x42cm
heres the nearly finished toroid
mhh, okay, now i have a problem, mh not a real problem, i get only about twice the discharge lenght of my secondary, but i know from my other drsstcs that i can get much more. the new toroid is finished and as i calculated i reduced the frequency to around 90khz i had to attach the primary to around 5,3 turns, . i tinkled with the on and off times and the funniest is that i get the longest streamers with a on time of around 80yS , more on time makes them shorter. mhh three weeks of building and now a dissapointing result?
mhh, heres a pic of the discharges at resonant frequency
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