Author Topic: Odd MOSFET Driver Behavior  (Read 2748 times)

Offline KrisPringle

  • High Voltage Enthusiast
  • *
  • Posts: 12
  • Karma: +0/-0
    • View Profile
Odd MOSFET Driver Behavior
« on: September 12, 2023, 03:32:01 AM »
I've been testing my driver for my first SSTC and am having some very weird problems with my MOSFET drivers. I've looked through the forum and never seen anything like it. It seems like each driver has a little extra blip of on-time after the actual on-time.

I attached some images of relevant scope traces and the schematics I'm using (Profdc9's). For the unloaded case, I'm scoping the low and high side of the GDT driver outputs with no transformer on the outputs. For the loaded case, I'm scoping the outputs with the gate drive connected to the full bridge.

I have no idea what would be causing this. Any clues? The MOSFET drivers get pretty warm after a few minutes of running the driver (CW mode, 15V).
« Last Edit: September 12, 2023, 03:40:50 AM by KrisPringle »

Offline davekni

  • Executive Board Member
  • *******
  • Posts: 2820
  • Karma: +134/-1
  • Physicist, engineer (electronic), and hobbiest
    • View Profile
Re: Odd MOSFET Driver Behavior
« Reply #1 on: September 12, 2023, 06:22:52 AM »
Quote
I have no idea what would be causing this. Any clues?
I might have time to make a better answer in a day or two.  Most likely your issue is with physical circuit construction.  Too much wire inductance in driver ground and supply connections, bypass caps not close enough, etc.

Quote
The MOSFET drivers get pretty warm after a few minutes of running the driver (CW mode, 15V).
CW mode often stresses drivers, so warm isn't unusual for CW operation.
« Last Edit: September 12, 2023, 06:29:17 AM by davekni »
David Knierim

Offline KrisPringle

  • High Voltage Enthusiast
  • *
  • Posts: 12
  • Karma: +0/-0
    • View Profile
Re: Odd MOSFET Driver Behavior
« Reply #2 on: September 12, 2023, 02:16:45 PM »
I might have time to make a better answer in a day or two.  Most likely your issue is with physical circuit construction.  Too much wire inductance in driver ground and supply connections, bypass caps not close enough, etc.

Not saying this definitely couldn't be true, but others seem to have had success using the same PCB layout. https://highvoltageforum.net/index.php?topic=1898.0

Is there anything I could scope that would confirm or reject your hypothesis?

I've attached a picture of the board as well as the board layout.

« Last Edit: September 12, 2023, 02:29:01 PM by KrisPringle »

Offline davekni

  • Executive Board Member
  • *******
  • Posts: 2820
  • Karma: +134/-1
  • Physicist, engineer (electronic), and hobbiest
    • View Profile
Re: Odd MOSFET Driver Behavior
« Reply #3 on: September 14, 2023, 05:37:20 AM »
Quote
I've attached a picture of the board as well as the board layout.
Layout looks good.  I'd been guessing you were using a hand wired breadboard for my previous comment.
However, this circuit design looks quite sensitive to noise.  TC4420 input traces are slow, especially falling edge, where voltage must fall to ~1.5V for output to switch.  With only 0.3V hysteresis, it doesn't take much noise (such as ground bounce inside TC4420) to make the extra output edges you see.  Notice that these noise pulses are all on falling edges.
40106 is slow and 4.7k series resistors will slow output further by the time it reaches TC4420.
One option is to add ~1k to 1.5k resistors from TC4420 inputs to ground.  That will attenuate signals to be roughly symmetric around TC4420 input threshold.
Sockets contribute to ground bounce inside chips.  Convenient for chip replacement, but have a significant down side.

Good luck with debug!  Thank you for posting details.
David Knierim

Offline KrisPringle

  • High Voltage Enthusiast
  • *
  • Posts: 12
  • Karma: +0/-0
    • View Profile
Re: Odd MOSFET Driver Behavior
« Reply #4 on: September 14, 2023, 03:07:24 PM »
Thanks for the help!

I will try removing the sockets. Also, the BOM called for 10k on those resistors but the schematic says 4.7k. I think I’ll also try replacing those 10k’s with 4.7k’s.

I will report back with results.

Offline davekni

  • Executive Board Member
  • *******
  • Posts: 2820
  • Karma: +134/-1
  • Physicist, engineer (electronic), and hobbiest
    • View Profile
Re: Odd MOSFET Driver Behavior
« Reply #5 on: September 14, 2023, 09:53:57 PM »
Quote
I will try removing the sockets.
It's the driver (TC4420) sockets that are of particular concern.  The other low-power chips are much less likely to have any issues due to sockets.

Quote
Also, the BOM called for 10k on those resistors but the schematic says 4.7k. I think I’ll also try replacing those 10k’s with 4.7k’s.
You could try even lower than 4.7k.  Also you may want to try pull-down resistors after 4.7k.  Driver chip input signal could be even better with a combination of pull-down resistors after 4.7k and small caps across 4.7k resistors to peak high frequencies, something in the range of 33pF to 100pF.  See what makes driver chip inputs look best (sharp rise and fall transitions, especially in region around 1.5V which is driver input threshold voltage).
David Knierim

Offline KrisPringle

  • High Voltage Enthusiast
  • *
  • Posts: 12
  • Karma: +0/-0
    • View Profile
Re: Odd MOSFET Driver Behavior
« Reply #6 on: September 16, 2023, 02:29:05 AM »
In an effort to not have to "jankify" the PCB, I tried just removing the MOSFET driver sockets and lowering the resistance to 4.7k. This didn't help, and the issue was still occurring. I wonder what is different about my board compared to others who have had success.

I tried using a 4.7k pull down resistor, and the GDT output looked good unloaded, but loaded, something was still wrong. (I think still the same issue as my original post, just to a lesser degree? I'm not sure through what mechanism the solution identified in the next paragraph works if it isn't the same issue.)

Unfortunately, I am not into much for hobby electronics outside this project, so I don't have a bunch of random capacitors lying around. I found a single 4700nf capacitor to throw across one of the 4.7ks, and voila! The rising edge of the waveform looks pretty good! Maybe a little over damped? The high frequency ringing before the output goes high: is that a problem? I don't have another capacitor to check if that's a symptom of the other driver not having the capacitor across it's resistor yet.


Offline davekni

  • Executive Board Member
  • *******
  • Posts: 2820
  • Karma: +134/-1
  • Physicist, engineer (electronic), and hobbiest
    • View Profile
Re: Odd MOSFET Driver Behavior
« Reply #7 on: September 16, 2023, 06:25:04 AM »
Quote
I tried using a 4.7k pull down resistor, and the GDT output looked good unloaded, but loaded, something was still wrong. (I think still the same issue as my original post, just to a lesser degree? I'm not sure through what mechanism the solution identified in the next paragraph works if it isn't the same issue.)
I'd guess that the 4.7k pull down resistors are working fine.  Loaded waveform is likely due to IGBT miller capacitance loading driver chip outputs.  However, it could be that 4.7k isn't enough pull-down.  Any ~2k resistors around?  Or enough 4.7k resistors to parallel 2 or 3 for each pull-down?

Quote
I found a single 4700nf capacitor to throw across one of the 4.7ks, and voila!
Did you mean 4700pF?  Even if so, that is still large.  Probably OK when used without a pull-down resistor.  I was suggesting a much smaller capacitor combined with a pull-down resistor.  However, combining the two does require getting capacitance correct to avoid driver chip inputs glitching too far below ground.

Quote
The rising edge of the waveform looks pretty good! Maybe a little over damped?
Once the input is clean enough to not glitch due to driver chip ground bounce, any remaining characteristics of driver outputs are due to driver output impedance and load impedance (GDT and IGBT gates).

Quote
The high frequency ringing before the output goes high: is that a problem?
Probably not an issue.  For such relatively small ringing, it is difficult to know if it is real or magnetic pickup in loop from scope probe ground lead to probe tip.

Quote
I don't have another capacitor to check if that's a symptom of the other driver not having the capacitor across it's resistor yet.
Probably best to have both channels modified to be the same.  There can be some advantage to a slight delay in one driver relative to the other.  However, any of these fixes (caps or pull-down resistors) will affect rising and falling delays differently.  If you have any lower-value resistors (ie. 2k), I'd guess that to be a more reliable fix than capacitors alone.  (If you have extra 4.7k resistors, two in parallel for each pull-down would be better than just one each.)  The pull-down resistor solution should move duty cycle closer to 50%.
« Last Edit: September 16, 2023, 06:26:36 AM by davekni »
David Knierim

Offline KrisPringle

  • High Voltage Enthusiast
  • *
  • Posts: 12
  • Karma: +0/-0
    • View Profile
Re: Odd MOSFET Driver Behavior
« Reply #8 on: September 16, 2023, 04:33:30 PM »
Quote
I'd guess that the 4.7k pull down resistors are working fine.  Loaded waveform is likely due to IGBT miller capacitance loading driver chip outputs.  However, it could be that 4.7k isn't enough pull-down.  Any ~2k resistors around?  Or enough 4.7k resistors to parallel 2 or 3 for each pull-down?

Gotcha, I have a resistor pack. The pulldown resistors are at 2k now, and unloaded output is good. No capacitors on it.

Loaded output still has a weird jump on one MOSFET driver. If this indeed from Miller Capacitance, that peak should reduce dramatically when the bridge is at mains voltage? Would you expect the traces to be asymmetric? The spikes are only on of the outputs.

Offline davekni

  • Executive Board Member
  • *******
  • Posts: 2820
  • Karma: +134/-1
  • Physicist, engineer (electronic), and hobbiest
    • View Profile
Re: Odd MOSFET Driver Behavior
« Reply #9 on: September 17, 2023, 05:19:47 AM »
Quote
Loaded output still has a weird jump on one MOSFET driver. If this indeed from Miller Capacitance, that peak should reduce dramatically when the bridge is at mains voltage? Would you expect the traces to be asymmetric? The spikes are only on of the outputs.
This capture does look less like Miller capacitance, more like driver chip ground bounce.  Loading may be adding just enough additional ground current spike to cause trouble.  Perhaps one chip has slightly higher inductance in ground path or has slightly faster output transition or more shoot-through current.  Previous loaded captures may have been ground bounce too.  They looked more like flat spots than spikes, which is typical of Miller capacitance.
David Knierim

Offline KrisPringle

  • High Voltage Enthusiast
  • *
  • Posts: 12
  • Karma: +0/-0
    • View Profile
Re: Odd MOSFET Driver Behavior
« Reply #10 on: March 25, 2024, 12:47:09 AM »
Picked my project back up, got everything ready for testing with the variac, and am running into more issues.

I believe my driver is working correctly, scoping at the full bridge shows some great looking square waves. However, something isn't working and I'm not sure what to even start looking for. These are symptoms I've seen, seems to be in line with IGBT shoot-through? The problem is if it's shoot through, I don't know how I can improve my GDT waveform any further.

  • The AC to DC bridge rectifier is getting obscenely hot at low voltage, like less than 10V. This has happened with 2 different bridge rectifiers (Mouser Part 78-GBU25H08-M3/P). The variac is also making a rather loud humming.
  • The IGBTs are also getting very hot at <10V to the bridge. All of them seem to be producing roughly equal amounts of heat.
  • When the driver is off, the bus capacitor holds its voltage and there's no short

Not an EE and not super experienced so I can't say for sure the IGBTs aren't broken, but I never saw the magic smoke, and testing resistances across the pins shows it's identical to a new IGBT. Is there anything else I can be looking for that can be causing this? For the low voltage testing I didn't have anything grounded, could that be causing this?

The driver and bridge design is the same as I've posted earlier in this thread from ProfDC9.

Offline davekni

  • Executive Board Member
  • *******
  • Posts: 2820
  • Karma: +134/-1
  • Physicist, engineer (electronic), and hobbiest
    • View Profile
Re: Odd MOSFET Driver Behavior
« Reply #11 on: March 25, 2024, 02:39:40 AM »
Most likely issue is GDT secondaries being mis-wired, causing the two IGBTs of a half-bridge to be on simultaneously.
David Knierim

Offline KrisPringle

  • High Voltage Enthusiast
  • *
  • Posts: 12
  • Karma: +0/-0
    • View Profile
Re: Odd MOSFET Driver Behavior
« Reply #12 on: March 25, 2024, 04:43:25 AM »
I have verified that I have labeled my GDT phases correctly, however I took a look at the PCB, and I'm wondering if I'm just missing something obvious. Is the phase labeling on the PCB incorrect/meaningless? I've been matching all the phases on my GDT to the PCB, but looks to me like that might not be right.

See the attached image, both GDT terminals labeled "+" go to the gate pin.

EDIT:
Good call on the phasing, fixed it to be properly phased and it seems to be working well. Only pushed it up to 50 volts but the dummy load was singing with my interrupter! Waiting for my top load then I should be in business.
« Last Edit: March 26, 2024, 02:32:36 AM by KrisPringle »

Offline KrisPringle

  • High Voltage Enthusiast
  • *
  • Posts: 12
  • Karma: +0/-0
    • View Profile
Re: Odd MOSFET Driver Behavior
« Reply #13 on: March 30, 2024, 01:33:25 AM »
Topload came in and I begun testing, ran into some issues.

I couldn't get any streamers to come out of the top-load, and a light bulb sitting on the topload didn't even light up. There's a section of my coil that was experiencing some secondary racing sparks, and I made some gnarly Lichtenberg figures on the inside of the PVC pipe (I think because my ground lead of the secondary coil was curled back up a few inches into the coil).

I transported my secondary before sealing it, and unfortunately it resulted in a less than perfect secondary with some crossing over. A few questions:

  • I can see how that would cause the racing sparks, but before I go ahead and make another secondary, is this indicative of a larger problem? Is a lack of streamers expected with a sub-par secondary experiencing racing sparks? I think I could stand to reduce the coupling or change the primary design, but I would figure that the current state would actually help create streamers at a higher risk of racing sparks. I had a breakout point on the toroid.
  • Are the racing sparks at least an indicator the inverter and antennae feedback are functioning properly? I was getting them by about 40V on the bridge. The top of the secondary also got warm
« Last Edit: March 30, 2024, 01:37:25 AM by KrisPringle »

Offline davekni

  • Executive Board Member
  • *******
  • Posts: 2820
  • Karma: +134/-1
  • Physicist, engineer (electronic), and hobbiest
    • View Profile
Re: Odd MOSFET Driver Behavior
« Reply #14 on: March 30, 2024, 07:22:03 PM »
Quote
Are the racing sparks at least an indicator the inverter and antennae feedback are functioning properly? I was getting them by about 40V on the bridge. The top of the secondary also got warm
Not necessarily.  One issue I've seen here with antenna feedback is antenna picking up signal more from part-way up secondary than from top.  Results in oscillation at a higher frequency mode of secondary.  No way to tell for sure given your damaged secondary.  Likely shorted turns at places.

Looking at your JavaTC results:
Most SSTCs have higher coupling, closer to 0.3.  Many have primary wound around section of plastic pipe or other insulating material that fits over secondary.  That increases coupling while reducing chance of secondary-to-primary arcs.
Also, a gap between top of secondary and top load is helpful, on the order of secondary radius.  Allows space for magnetic field lines to return.
David Knierim

High Voltage Forum

Re: Odd MOSFET Driver Behavior
« Reply #14 on: March 30, 2024, 07:22:03 PM »

 


* Recent Topics and Posts

post Re: Turning SSTC into DRSSTC
[Dual Resonant Solid State Tesla coils (DRSSTC)]
Simranjit
Today at 02:14:17 AM
post Re: Turning SSTC into DRSSTC
[Dual Resonant Solid State Tesla coils (DRSSTC)]
flyingperson23
June 12, 2024, 11:04:57 PM
post Turning SSTC into DRSSTC
[Dual Resonant Solid State Tesla coils (DRSSTC)]
Simranjit
June 12, 2024, 10:23:08 PM
post Re: UD2.7C constantly in OCP despite having signal
[Dual Resonant Solid State Tesla coils (DRSSTC)]
verliebt_in_neukölln17
June 12, 2024, 08:41:06 PM
post Re: UD2.7C constantly in OCP despite having signal
[Dual Resonant Solid State Tesla coils (DRSSTC)]
flyingperson23
June 12, 2024, 07:53:31 PM
post Re: Van de Graaf Voltage measurement with voltage sensor and voltage divider
[Static Electricity]
haversin
June 12, 2024, 06:57:13 PM
post UD2.7C constantly in OCP despite having signal
[Dual Resonant Solid State Tesla coils (DRSSTC)]
verliebt_in_neukölln17
June 12, 2024, 06:54:49 PM
post Re: Van de Graaf Voltage measurement with voltage sensor and voltage divider
[Static Electricity]
Mads Barnkob
June 12, 2024, 03:47:28 PM
post Van de Graaf Voltage measurement with voltage sensor and voltage divider
[Static Electricity]
vK
June 12, 2024, 03:42:18 AM
post Re: Bigger sparks?...
[Vacuum Tube Tesla Coils (VTTC)]
davekni
June 12, 2024, 03:32:22 AM
post Re: Bigger sparks?...
[Vacuum Tube Tesla Coils (VTTC)]
Teslaventje
June 11, 2024, 11:05:49 PM
post Re: Bigger sparks?...
[Vacuum Tube Tesla Coils (VTTC)]
MRMILSTAR
June 11, 2024, 05:36:46 AM
post Re: Sling Psychrometer
[Laboratories, Equipment and Tools]
Twospoons
June 11, 2024, 12:29:31 AM
post Bigger sparks?...
[Vacuum Tube Tesla Coils (VTTC)]
Teslaventje
June 10, 2024, 11:05:55 PM
post Re: Syntherrupter - A Feature-rich, Polyphonic Interrupter
[Computers, Microcontrollers, Programmable Logic, Interfaces and Displays]
Max
June 10, 2024, 10:57:51 PM
post Re: Benjamin's DRSSTC3
[Dual Resonant Solid State Tesla coils (DRSSTC)]
Benjamin Lockhart
June 10, 2024, 08:08:04 PM
post Re: Plasma Torid - Class E Self Resonant Dual/Stereo - Plasma Torid Build
[Dual Resonant Solid State Tesla coils (DRSSTC)]
Hi-Deff
June 10, 2024, 06:04:09 PM
post Sling Psychrometer
[Laboratories, Equipment and Tools]
klugesmith
June 10, 2024, 04:43:59 PM
post Re: Benjamin's DRSSTC3
[Dual Resonant Solid State Tesla coils (DRSSTC)]
flyingperson23
June 10, 2024, 03:35:28 PM
post Re: Benjamin's DRSSTC3
[Dual Resonant Solid State Tesla coils (DRSSTC)]
Jj
June 10, 2024, 01:36:41 PM
post Re: Is a 60UF 800VDC Dawncap good for an induction heater?
[General Chat]
Anders Mikkelsen
June 09, 2024, 05:44:29 PM
post Is a 60UF 800VDC Dawncap good for an induction heater?
[General Chat]
yourboi
June 09, 2024, 03:31:30 PM
post Re: Steve Ward's DRSSTC Interrupter stops working when adjusting pulse width
[Electronic Circuits]
NyaaX_X
June 09, 2024, 01:34:49 PM
post Steve Ward's DRSSTC Interrupter stops working when adjusting pulse width
[Electronic Circuits]
verliebt_in_neukölln17
June 09, 2024, 01:56:51 AM
post Re: Return of Electronics Flea Market in "Silicon Valley"
[Sell / Buy / Trade]
klugesmith
June 08, 2024, 06:06:25 AM
post Re: Coulometric hourmeters
[Laboratories, Equipment and Tools]
klugesmith
June 08, 2024, 05:38:14 AM
post Interrupter for SSTC
[Beginners]
Simranjit
June 08, 2024, 12:47:47 AM
post Re: Adding capacitor to primary in SSTC
[Solid State Tesla Coils (SSTC)]
Michelle_
June 07, 2024, 03:59:57 PM
post Re: Adding capacitor to primary in SSTC
[Solid State Tesla Coils (SSTC)]
davekni
June 07, 2024, 06:42:26 AM
post Re: Space-X Starship test this week
[Science, Research and News In Other Fields Than Electronics]
MRMILSTAR
June 07, 2024, 05:08:00 AM
post Re: Half bridge sstc different waveform on two mosfets
[Solid State Tesla Coils (SSTC)]
davekni
June 07, 2024, 03:16:31 AM
post Re: Space-X Starship test this week
[Science, Research and News In Other Fields Than Electronics]
klugesmith
June 06, 2024, 11:37:20 PM
post Adding capacitor to primary in SSTC
[Solid State Tesla Coils (SSTC)]
Simranjit
June 06, 2024, 11:20:23 PM
post Re: Plasma Torid - Class E Self Resonant Dual/Stereo - Plasma Torid Build
[Dual Resonant Solid State Tesla coils (DRSSTC)]
alan sailer
June 06, 2024, 10:54:48 PM
post Re: Half bridge sstc different waveform on two mosfets
[Solid State Tesla Coils (SSTC)]
ZakW
June 06, 2024, 05:17:02 AM
post Re: Half bridge sstc different waveform on two mosfets
[Solid State Tesla Coils (SSTC)]
Simranjit
June 06, 2024, 04:50:00 AM
post Re: Half bridge sstc different waveform on two mosfets
[Solid State Tesla Coils (SSTC)]
davekni
June 06, 2024, 04:00:52 AM
post Re: Half bridge sstc different waveform on two mosfets
[Solid State Tesla Coils (SSTC)]
ZakW
June 06, 2024, 01:43:41 AM
post Re: Half bridge sstc different waveform on two mosfets
[Solid State Tesla Coils (SSTC)]
Simranjit
June 05, 2024, 11:11:17 PM
post Re: Half bridge sstc different waveform on two mosfets
[Solid State Tesla Coils (SSTC)]
Michelle_
June 05, 2024, 10:18:57 PM
post Re: Half bridge sstc different waveform on two mosfets
[Solid State Tesla Coils (SSTC)]
Simranjit
June 05, 2024, 10:13:03 PM
post Re: Half bridge sstc different waveform on two mosfets
[Solid State Tesla Coils (SSTC)]
ZakW
June 05, 2024, 09:29:18 PM
post Half bridge sstc different waveform on two mosfets
[Solid State Tesla Coils (SSTC)]
Simranjit
June 05, 2024, 08:46:53 PM
post Re: Want to build HV HF oscilloscope probe.
[Electronic Circuits]
Twospoons
June 05, 2024, 07:04:45 AM
post Re: Want to build HV HF oscilloscope probe.
[Electronic Circuits]
Domo
June 05, 2024, 04:58:35 AM
post Re: Pearson current monitor model 1330 teardown (100kA)
[Laboratories, Equipment and Tools]
klugesmith
June 05, 2024, 01:42:04 AM
post Re: Coulometric hourmeters
[Laboratories, Equipment and Tools]
klugesmith
June 04, 2024, 10:31:58 PM
post Re: My completed 14-stage Cockroft-Walton voltage multiplier
[Voltage Multipliers]
pete_dl
June 04, 2024, 08:08:28 PM
post Re: Want to build HV HF oscilloscope probe.
[Electronic Circuits]
Twospoons
June 03, 2024, 11:13:26 PM
post Re: First DRSSTC questions
[Dual Resonant Solid State Tesla coils (DRSSTC)]
Benjamin Lockhart
June 03, 2024, 10:35:57 PM
post Re: First DRSSTC questions
[Dual Resonant Solid State Tesla coils (DRSSTC)]
Hi-Deff
June 03, 2024, 05:51:05 PM
post Re: Want to build HV HF oscilloscope probe.
[Electronic Circuits]
Domo
June 03, 2024, 07:41:41 AM
post Re: First DRSSTC questions
[Dual Resonant Solid State Tesla coils (DRSSTC)]
flyingperson23
June 03, 2024, 05:28:44 AM
post Re: RDRSSTC - Project Build
[Dual Resonant Solid State Tesla coils (DRSSTC)]
davekni
June 03, 2024, 05:02:19 AM
post Re: First DRSSTC questions
[Dual Resonant Solid State Tesla coils (DRSSTC)]
Benjamin Lockhart
June 03, 2024, 03:47:33 AM
post Re: First DRSSTC questions
[Dual Resonant Solid State Tesla coils (DRSSTC)]
flyingperson23
June 03, 2024, 02:23:58 AM
post Re: First DRSSTC questions
[Dual Resonant Solid State Tesla coils (DRSSTC)]
Hi-Deff
June 03, 2024, 01:25:24 AM
post Re: RDRSSTC - Project Build
[Dual Resonant Solid State Tesla coils (DRSSTC)]
ZakW
June 03, 2024, 01:08:47 AM
post Re: RDRSSTC - Project Build
[Dual Resonant Solid State Tesla coils (DRSSTC)]
davekni
June 02, 2024, 10:29:02 PM
post Re: Steve Ward SSTC5 build
[Solid State Tesla Coils (SSTC)]
Michelle_
June 02, 2024, 10:02:45 PM
post Re: Racing sparks
[Spark Gap Tesla Coils (SGTC)]
davekni
June 02, 2024, 08:25:37 PM
post Re: Steve Ward SSTC5 build
[Solid State Tesla Coils (SSTC)]
Michelle_
June 02, 2024, 04:51:58 PM
post Re: RDRSSTC - Project Build
[Dual Resonant Solid State Tesla coils (DRSSTC)]
Michelle_
June 02, 2024, 04:44:30 PM
post Re: My completed 14-stage Cockroft-Walton voltage multiplier
[Voltage Multipliers]
MRMILSTAR
June 02, 2024, 03:25:11 PM
post APC Smart-UPS 1500VA Teardown
[Electronic Circuits]
Mads Barnkob
June 02, 2024, 01:36:11 PM
post Re: My completed 14-stage Cockroft-Walton voltage multiplier
[Voltage Multipliers]
pete_dl
June 02, 2024, 11:43:40 AM
post Re: RDRSSTC - Project Build
[Dual Resonant Solid State Tesla coils (DRSSTC)]
ZakW
June 02, 2024, 08:49:11 AM
post Re: RDRSSTC - Project Build
[Dual Resonant Solid State Tesla coils (DRSSTC)]
Benjamin Lockhart
June 02, 2024, 08:36:07 AM
post Re: RDRSSTC - Project Build
[Dual Resonant Solid State Tesla coils (DRSSTC)]
ZakW
June 02, 2024, 12:41:50 AM
post Re: Steve Ward SSTC5 build
[Solid State Tesla Coils (SSTC)]
Benjamin Lockhart
June 01, 2024, 08:24:35 PM
post Pearson current monitor model 1330 teardown (100kA)
[Laboratories, Equipment and Tools]
Mads Barnkob
June 01, 2024, 08:22:28 PM
post Re: Steve Ward SSTC5 build
[Solid State Tesla Coils (SSTC)]
Michelle_
June 01, 2024, 03:56:53 AM
post Re: Racing sparks
[Spark Gap Tesla Coils (SGTC)]
Terry
June 01, 2024, 12:03:50 AM
post Re: First DRSSTC questions
[Dual Resonant Solid State Tesla coils (DRSSTC)]
Hi-Deff
May 31, 2024, 11:46:20 PM
post Re: Steve Ward SSTC5 build
[Solid State Tesla Coils (SSTC)]
Michelle_
May 31, 2024, 06:13:59 PM
post Re: First DRSSTC questions
[Dual Resonant Solid State Tesla coils (DRSSTC)]
davekni
May 31, 2024, 01:55:22 AM
post Re: First DRSSTC questions
[Dual Resonant Solid State Tesla coils (DRSSTC)]
flyingperson23
May 30, 2024, 11:57:49 PM
post Re: First DRSSTC questions
[Dual Resonant Solid State Tesla coils (DRSSTC)]
Benjamin Lockhart
May 30, 2024, 11:50:06 PM
post First DRSSTC questions
[Dual Resonant Solid State Tesla coils (DRSSTC)]
Hi-Deff
May 30, 2024, 11:23:35 PM
post Re: Steve Ward SSTC5 build
[Solid State Tesla Coils (SSTC)]
davekni
May 30, 2024, 10:43:06 PM
post Re: Benjamin's DRSSTC3
[Dual Resonant Solid State Tesla coils (DRSSTC)]
davekni
May 30, 2024, 10:24:35 PM
post Re: SSTC tripping circuit breaker
[Solid State Tesla Coils (SSTC)]
NyaaX_X
May 30, 2024, 06:10:04 PM
post Re: SSTC tripping circuit breaker
[Solid State Tesla Coils (SSTC)]
Simranjit
May 30, 2024, 04:56:11 PM
post Re: SSTC tripping circuit breaker
[Solid State Tesla Coils (SSTC)]
Michelle_
May 30, 2024, 04:48:05 PM
post Re: Steve Ward SSTC5 build
[Solid State Tesla Coils (SSTC)]
Michelle_
May 30, 2024, 04:37:22 PM
post Re: SSTC tripping circuit breaker
[Solid State Tesla Coils (SSTC)]
klugesmith
May 30, 2024, 04:16:31 PM
post Re: SSTC tripping circuit breaker
[Solid State Tesla Coils (SSTC)]
NyaaX_X
May 30, 2024, 03:34:10 PM
post Re: SSTC tripping circuit breaker
[Solid State Tesla Coils (SSTC)]
Simranjit
May 30, 2024, 02:53:50 PM
post Re: SSTC tripping circuit breaker
[Solid State Tesla Coils (SSTC)]
NyaaX_X
May 30, 2024, 12:44:47 PM
post SSTC tripping circuit breaker
[Solid State Tesla Coils (SSTC)]
Simranjit
May 30, 2024, 07:52:56 AM
post Re: Steve Ward SSTC5 build
[Solid State Tesla Coils (SSTC)]
NyaaX_X
May 30, 2024, 07:07:53 AM
post Re: Benjamin's DRSSTC3
[Dual Resonant Solid State Tesla coils (DRSSTC)]
Benjamin Lockhart
May 30, 2024, 07:04:40 AM
post Re: Steve Ward SSTC5 build
[Solid State Tesla Coils (SSTC)]
Michelle_
May 30, 2024, 05:16:50 AM
post Re: Steve Ward SSTC5 build
[Solid State Tesla Coils (SSTC)]
Michelle_
May 30, 2024, 05:08:17 AM
post Re: Steve Ward SSTC5 build
[Solid State Tesla Coils (SSTC)]
davekni
May 30, 2024, 04:29:30 AM
post Re: Benjamin's DRSSTC3
[Dual Resonant Solid State Tesla coils (DRSSTC)]
davekni
May 30, 2024, 03:52:36 AM
post Re: Racing sparks
[Spark Gap Tesla Coils (SGTC)]
davekni
May 30, 2024, 03:47:12 AM
post Re: Steve Ward SSTC5 build
[Solid State Tesla Coils (SSTC)]
Benjamin Lockhart
May 30, 2024, 03:41:34 AM
post Re: Steve Ward SSTC5 build
[Solid State Tesla Coils (SSTC)]
Michelle_
May 30, 2024, 03:27:28 AM
post Re: Steve Ward SSTC5 build
[Solid State Tesla Coils (SSTC)]
Michelle_
May 29, 2024, 03:55:16 PM

Sitemap 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 
SimplePortal 2.3.6 © 2008-2014, SimplePortal