Author Topic: MMC capacitor crash  (Read 2329 times)

Offline JCF

  • High Voltage Experimenter
  • **
  • Posts: 75
  • Karma: +1/-0
    • View Profile
MMC capacitor crash
« on: August 27, 2022, 12:11:53 PM »
Hello everyone, I experienced 2 crashes of my MMC this year with Cornell-Dubilier 940C 47nF 3kV dc ±10% Thin Film Capacitor

First crash capacitor exploded
second opening crash and black leak on the IC
The operating voltage was 200Vdc.
The MMC is a combination of 3 x 3 capacitor.

What append ? 200Vdc is low, Is this a problem with the pulse width being too large? A failure of a capacitor (always at the beginning of one of the rows of the MMC
What is the maximum pulse width not to exceed, frequency around 20Hz

For the design of the tesla coil see https://highvoltageforum.net/index.php?topic=1695.msg13172#msg13172





Offline Mike

  • High Voltage Enthusiast
  • *
  • Posts: 41
  • Karma: +3/-0
    • View Profile
Re: MMC capacitor crash
« Reply #1 on: August 27, 2022, 12:59:42 PM »
From the datasheet we can see that your individual caps are rated for 68A pk and 5.7A rms. Your 3x3 MMC is rated for 3 times that so 204A pk and 17.1A rms. If your frequency is 20Hz and you're under the peak current rating, that makes the maximum pulse width about 420us.

You also need to check the maximum voltage you're exposing your capacitor to. This is found by calculating the capacitors impedance at your resonant frequency (Xc = 1 / (2πfC)) and multiplying that by your peak resonant current. If your peak voltage is less than the rated DC voltage you're probably ok.
« Last Edit: August 27, 2022, 01:02:42 PM by Mike »

Offline Mads Barnkob

  • Administrator
  • Executive Board Member
  • *****
  • Posts: 2046
  • Karma: +55/-0
  • Denmark
    • View Profile
    • Kaizer Power Electronics
Re: MMC capacitor crash
« Reply #2 on: August 27, 2022, 01:08:42 PM »
What does the backside of that MMC look like? Since you say its always the first row, sounds like you have a load imbalance or capacitance imbalance, which would result in a load imbalance...

You can check your MMC design fast with the MMC calculator: https://kaizerpowerelectronics.dk/calculators/mmc-calculator/

As Mike notes, 420us maximum pulse width is lower than the 750us you said you were running it at, which means you cooked them from excessive heat dissipation.
https://kaizerpowerelectronics.dk - Tesla coils, high voltage, pulse power, audio and general electronics
https://www.youtube.com/KaizerPowerElectronicsDk60/join - Please consider supporting the forum, websites and youtube channel!

Offline JCF

  • High Voltage Experimenter
  • **
  • Posts: 75
  • Karma: +1/-0
    • View Profile
Re: MMC capacitor crash
« Reply #3 on: August 27, 2022, 04:15:18 PM »
the rear wiring is essentially made with the tails of the capacitors and resistors. it's not massive at all. if it takes a piece of copper of 2mm diameter I will do something more consistent.

for the connection with the bridge and the primary, it is a large multi-strand copper wire 6 mm2 top left and bottom right

résonance frequency of coil is 130khz

the wiring is really very badly made ....!



* Spec Capacitor.pdf

« Last Edit: August 27, 2022, 04:40:11 PM by JCF »

Offline klugesmith

  • High Voltage Senior
  • *****
  • Posts: 557
  • Karma: +18/-0
    • View Profile
Re: MMC capacitor crash
« Reply #4 on: August 27, 2022, 05:08:30 PM »
>> if it takes a piece of copper of 2mm diameter I will do something more consistent.

Mads warned of un-balanced currents in the MMC.
In your case, the partition of current between three branches is affected by inductance much more than wire resistance.
Adding copper without moving the capacitors and changing loop areas won't make much of a difference. 

Offline Mads Barnkob

  • Administrator
  • Executive Board Member
  • *****
  • Posts: 2046
  • Karma: +55/-0
  • Denmark
    • View Profile
    • Kaizer Power Electronics
Re: MMC capacitor crash
« Reply #5 on: August 27, 2022, 07:32:02 PM »
It is the results with your primary coil inductance for the MMC calculator that is interesting, not the first part you screenshotted :) The bottom results of what the MMC specifications are and what they actually see at load.

Please take out the MMC for a proper picture of the backside, its impossible to evaluate the wiring from that picture. It looks like you did connect in opposite corners, but did you put everything in parallel / series like a matrice? It should just be parallel strings, not connections between the strings in the middle of them.
https://kaizerpowerelectronics.dk - Tesla coils, high voltage, pulse power, audio and general electronics
https://www.youtube.com/KaizerPowerElectronicsDk60/join - Please consider supporting the forum, websites and youtube channel!

Offline JCF

  • High Voltage Experimenter
  • **
  • Posts: 75
  • Karma: +1/-0
    • View Profile
Re: MMC capacitor crash
« Reply #6 on: August 28, 2022, 10:55:18 AM »
thank for help
MMC is 3 lines of 3 capacitors in serie with // resistors, each line connected at right and left in paralell.

« Last Edit: August 28, 2022, 04:27:33 PM by JCF »

Offline davekni

  • High Voltage Expert
  • ******
  • Posts: 1899
  • Karma: +95/-1
  • Physicist, engineer (electronic), and hobbiest
    • View Profile
Re: MMC capacitor crash
« Reply #7 on: August 28, 2022, 09:01:47 PM »
Quote
thank for help
MMC is 3 lines of 3 capacitors in serie with // resistors, each line connected at right and left in paralell.
Three possible causes of failure come to mind:
1) Perhaps there's a wiring mistake and it's not as intended (not as attached diagram in last post).
2) MMC wiring is spaced so close that arcs form between wires.
3) Higher RMS current than capacitors can handle.
My first guess would be (3).  Have you checked capacitor temperature immediately after a run?  What duty-cycle are you running (burst length as a fraction of period from one burst to the next) and what primary current?

Film capacitors such as these usually fail somewhat gradually before final rupture.  Capacitance drops first, then leakage current goes up, then failure.  I'd suggest measuring each capacitor to see if you have others that are on their way toward failure.  Within MMC array, measured value for any individual capacitor will include some contribution from remainder of MMC, so will measure ~28% high in your case.  Still useful in comparing readings of all 9 capacitors.
« Last Edit: August 28, 2022, 09:24:08 PM by davekni »
David Knierim

Offline Hydron

  • Administrator
  • High Voltage Engineer
  • *****
  • Posts: 451
  • Karma: +19/-0
    • View Profile
Re: MMC capacitor crash
« Reply #8 on: August 29, 2022, 09:40:10 AM »
It is the results with your primary coil inductance for the MMC calculator that is interesting, not the first part you screenshotted :) The bottom results of what the MMC specifications are and what they actually see at load.

Please take out the MMC for a proper picture of the backside, its impossible to evaluate the wiring from that picture. It looks like you did connect in opposite corners, but did you put everything in parallel / series like a matrice? It should just be parallel strings, not connections between the strings in the middle of them.
I would run the impedance numbers at the operating frequency before worrying about the layout too much - I suspect that you'd find that the wiring between parallel strings of caps would need to be seriously inductive (a big coil or something) to make a noticeable difference in current sharing.
Remember that at the resonant frequency the primary coil impedance is the same as the MMC impedance, so a little bit of extra wire will make very little difference compared to the impedance of the cap string. This is not like trying to share current between parallel connector pins or something (where the contact impedance is probably the biggest and most variable impedance) - the capacitor strings each have their own, large (compared to the inductance of the bus-bar) impedance, which will force current sharing.
« Last Edit: August 29, 2022, 09:42:10 AM by Hydron »

Offline JCF

  • High Voltage Experimenter
  • **
  • Posts: 75
  • Karma: +1/-0
    • View Profile
Re: MMC capacitor crash
« Reply #9 on: August 30, 2022, 04:40:33 PM »
Hello,
here are the photos of the MMC on the wiring side, and the lower part and cable of the coil.
I removed the small piece of solder on the body of one of the resistors, this is not a defect.

I will take measurements soon (primary current, Max spike at output bridge : IGBTCM200DU-12F (600V 200A).

the capacitors all have approximately the same capacitance value.


« Last Edit: August 30, 2022, 05:01:58 PM by JCF »

Offline davekni

  • High Voltage Expert
  • ******
  • Posts: 1899
  • Karma: +95/-1
  • Physicist, engineer (electronic), and hobbiest
    • View Profile
Re: MMC capacitor crash
« Reply #10 on: August 31, 2022, 03:44:57 AM »
Quote
here are the photos of the MMC on the wiring side, and the lower part and cable of the coil.
Don't see any issues in MMC wiring.  I'd guess just too-high duty cycle making RMS current high, overheating capacitors.  There will be hot-spots within capacitor.  Still, I'd expect overall case temperature to be fairly warm if RMS current is the issue.

Quote
the capacitors all have approximately the same capacitance value.
Roughly how much variation?  Can be difficult to detect issues without knowing initial capacitance.  The caps I've tested to destruction drop only 5-10% before failure.

Quote
I will take measurements soon (primary current, Max spike at output bridge : IGBTCM200DU-12F (600V 200A).
That will be useful.  Needs to include duty cycle information as well (repetition rate and duration of primary current within each burst).

Good luck with avoiding future failures!
David Knierim

Offline JCF

  • High Voltage Experimenter
  • **
  • Posts: 75
  • Karma: +1/-0
    • View Profile
Re: MMC capacitor crash
« Reply #11 on: September 01, 2022, 11:52:13 AM »
Thank you for your help which I appreciate
what brand of capacitors should be purchased to avoid overcharging problems? on eBay?

Offline Mads Barnkob

  • Administrator
  • Executive Board Member
  • *****
  • Posts: 2046
  • Karma: +55/-0
  • Denmark
    • View Profile
    • Kaizer Power Electronics
Re: MMC capacitor crash
« Reply #12 on: September 01, 2022, 11:15:05 PM »
Thank you for your help which I appreciate
what brand of capacitors should be purchased to avoid overcharging problems? on eBay?

It is your design or how hard you drive them, that has to change. You were already using CDE 940 series pulse capacitors, some of the best known/well proven Tesla coiling durable MMC capacitors.

If you want something that can withstand the abuse you gave to these, look for GTO snubber capacitor, DC bus snubbers or resonant capacitors. But these you can all kill from driving them hard outside of their thermal limits, like you did with the CDE 940s
https://kaizerpowerelectronics.dk - Tesla coils, high voltage, pulse power, audio and general electronics
https://www.youtube.com/KaizerPowerElectronicsDk60/join - Please consider supporting the forum, websites and youtube channel!

Offline JCF

  • High Voltage Experimenter
  • **
  • Posts: 75
  • Karma: +1/-0
    • View Profile
Re: MMC capacitor crash
« Reply #13 on: September 02, 2022, 11:53:33 AM »
Thanks for the warnings about the duty cycle
I will therefore do measurements + calculation to see what is happening at the level of the MMC

Offline JCF

  • High Voltage Experimenter
  • **
  • Posts: 75
  • Karma: +1/-0
    • View Profile
Re: MMC capacitor crash
« Reply #14 on: September 13, 2022, 06:00:00 PM »
Hello. I pulled out the material to make measure…. I do not understand what is happening with the appearance of the primary signal (with differential probe) ? ?
Vdc : 60/70V at full bridge. Current transformer 1/300 on 100 Ohms. No OCD connected
Too much coupling ?




third pict is what I had several months ago before the crash of the MMC (repair I change two capacitors)




« Last Edit: September 15, 2022, 04:22:13 PM by JCF »

Offline JCF

  • High Voltage Experimenter
  • **
  • Posts: 75
  • Karma: +1/-0
    • View Profile
Re: MMC capacitor crash
« Reply #15 on: September 14, 2022, 03:43:03 PM »
Hi measurements of the day with a generator on the feedback
the frequency of the generator is marked in the filename.
what deduce the frequency of the primary is too close ?


« Last Edit: September 14, 2022, 03:50:14 PM by JCF »

Offline davekni

  • High Voltage Expert
  • ******
  • Posts: 1899
  • Karma: +95/-1
  • Physicist, engineer (electronic), and hobbiest
    • View Profile
Re: MMC capacitor crash
« Reply #16 on: September 15, 2022, 05:54:55 AM »
All of your new scope captures appear to show little energy transfer to secondary.  Current rises higher for a given bus voltage with no obvious cyclic nature of current growth (beat frequency between primary and secondary) as shows up in the one old scope capture image.  I'd guess either far-mismatched primary and secondary frequencies or little coupling.  Mismatched frequencies could be due to a missing top load or secondary ground, anything that changes secondary resonant frequency.

A couple other observations:
1) A couple of the latest images show clipping (over-voltage) of your differential probe.  Change to 500x mode.
2) Differential probe connection and/or H-bridge has significant inductance, adding LdV/dt to H-bridge output signal.  If you can, run differential probe wires from H-bridge the opposite direction as connections to MMC and primary coil.  Twist or otherwise pair together probe leads.
3) Dead-time looks good.  Shows up in triple-transitions on SDS00155k25_02.png image.
David Knierim

Offline JCF

  • High Voltage Experimenter
  • **
  • Posts: 75
  • Karma: +1/-0
    • View Profile
Re: MMC capacitor crash
« Reply #17 on: September 15, 2022, 04:15:12 PM »
thanks very much Dave. I did not understand very well.
do I have to understand that the first oscillogram was good ?  SDS00004.png (with feed back secondary connected). I thought I saw a square signal and is no the case



"If you can, run differential probe wires from H-bridge the opposite direction as connections to MMC and primary coil...."  is reverse differential probe ? currently I am on the output of the bridge.
 
« Last Edit: September 15, 2022, 05:17:51 PM by JCF »

Offline davekni

  • High Voltage Expert
  • ******
  • Posts: 1899
  • Karma: +95/-1
  • Physicist, engineer (electronic), and hobbiest
    • View Profile
Re: MMC capacitor crash
« Reply #18 on: September 16, 2022, 05:40:05 AM »
Quote
do I have to understand that the first oscillogram was good ?  SDS00004.png (with feed back secondary connected). I thought I saw a square signal and is no the case
Am I correct that SDS00012.png is the a capture from before MMC crash?  That capture looks good with one exception: H-bridge voltage phase is lagging current rather than slightly leading as is preferred.  SDS00012.png shows periodic increases in primary current as would be expected for coupled resonators.  SDS00004.png shows primary current ramping continuously to about 3x the current shown in SDS00012.png.  Both the higher current and lack of periodicity in increase indicate energy is not transferring to secondary.  BTW, at least the zoomed-in capture SDS00003.png shows sufficient phase lead.

Quote
"If you can, run differential probe wires from H-bridge the opposite direction as connections to MMC and primary coil...."  is reverse differential probe ? currently I am on the output of the bridge.
Connecting to H-bridge output is correct.    I'm suggesting only that the probe wires be routed a different direction and connected to the output as close to IGBTs as is reasonable.  How were scope wires routed for your old SDS00012.png capture?  That capture shows less of the sine-wave current signal added to H-bridge output.  Newer captures all show large sine-wave current signal added to H-bridge voltage.  That makes interpreting the traces more difficult.  That sine-wave current signal is not likely real at the IGBTs.  It gets added by either common inductance (scope leads connected to H-bridge output farther away from IGBTs, closer to MMC or primary coil) or by mutual inductance (scope probe wires not paired close to each other with magnetic field from primary coil or leads passing between scope probe wires).
David Knierim

Offline JCF

  • High Voltage Experimenter
  • **
  • Posts: 75
  • Karma: +1/-0
    • View Profile
Re: MMC capacitor crash
« Reply #19 on: September 16, 2022, 04:17:31 PM »
Thanks David
I realize that I did very little measurement around the resonance frequency
here generator input feedback f = 153khz
fiber optic input 10 Hz 200µS.
Vdc bus 60Vdc



on 3 captures I see more or less long traces for the primary
the sound of the spark is more or less loud.
why this change in length ? instability ? vbus too low,

what to do ? it's normal ?

the first and last trace shows a frequency very close to 152.60 with a different length for primary signal ?




« Last Edit: September 16, 2022, 04:40:23 PM by JCF »

High Voltage Forum

Re: MMC capacitor crash
« Reply #19 on: September 16, 2022, 04:17:31 PM »

 


* Recent Topics and Posts

post Re: Plasma Toroid
[Solid State Tesla Coils (SSTC)]
klugesmith
Today at 09:35:18 AM
post Re: Plasma Toroid
[Solid State Tesla Coils (SSTC)]
DashApple
Today at 07:37:22 AM
post Re: UD2.7 onwards - post-2014 changes published anywhere?
[Dual Resonant Solid State Tesla coils (DRSSTC)]
davekni
Today at 05:17:26 AM
post Re: Plasma Toroid
[Solid State Tesla Coils (SSTC)]
davekni
Today at 04:51:33 AM
post Re: Slayer exciter circuit - struggling with how it works
[Solid State Tesla Coils (SSTC)]
Twospoons
Today at 04:43:37 AM
post [WTB] IF D95T / IF D95OC optic receiver
[Sell / Buy / Trade]
RoamingD
November 29, 2022, 10:23:35 PM
post Re: UD2.7 onwards - post-2014 changes published anywhere?
[Dual Resonant Solid State Tesla coils (DRSSTC)]
Mads Barnkob
November 29, 2022, 09:14:10 PM
post UD2.7 onwards - post-2014 changes published anywhere?
[Dual Resonant Solid State Tesla coils (DRSSTC)]
AkashaStar
November 29, 2022, 07:32:37 PM
post 8000FPS Slow Motion Tesla Coil Spark Formation and Collapsing Hot Spots
[Solid State Tesla Coils (SSTC)]
Mads Barnkob
November 29, 2022, 05:21:49 PM
post Re: Plasma Toroid
[Solid State Tesla Coils (SSTC)]
alan sailer
November 29, 2022, 04:08:00 PM
post Re: Plasma Toroid
[Solid State Tesla Coils (SSTC)]
kurtrox
November 29, 2022, 05:51:59 AM
post Re: Induction cooker without electronics
[Electronic Circuits]
Solhi
November 29, 2022, 01:25:43 AM
post Re: Induction cooker without electronics
[Electronic Circuits]
Twospoons
November 28, 2022, 10:09:56 PM
post Re: Plasma Toroid
[Solid State Tesla Coils (SSTC)]
Uspring
November 28, 2022, 06:01:14 PM
post Slayer exciter circuit - struggling with how it works
[Solid State Tesla Coils (SSTC)]
Tatranka
November 28, 2022, 02:57:17 PM
post Re: Induction cooker without electronics
[Electronic Circuits]
Solhi
November 28, 2022, 11:38:26 AM
post Re: Induction cooker without electronics
[Electronic Circuits]
klugesmith
November 28, 2022, 11:22:51 AM
post Re: Induction cooker without electronics
[Electronic Circuits]
Solhi
November 28, 2022, 05:55:16 AM
post Re: Plasma Toroid
[Solid State Tesla Coils (SSTC)]
klugesmith
November 28, 2022, 05:21:37 AM
post Re: Plasma Toroid
[Solid State Tesla Coils (SSTC)]
davekni
November 28, 2022, 03:26:55 AM
post Re: Plasma Toroid
[Solid State Tesla Coils (SSTC)]
klugesmith
November 28, 2022, 02:09:06 AM
post Re: Plasma Toroid
[Solid State Tesla Coils (SSTC)]
alan sailer
November 28, 2022, 12:06:02 AM
post Re: Induction cooker without electronics
[Electronic Circuits]
klugesmith
November 27, 2022, 06:05:52 PM
post Re: Induction cooker without electronics
[Electronic Circuits]
Solhi
November 27, 2022, 01:24:05 PM
post Re: ZVS driver won't oscillate
[Electronic Circuits]
davekni
November 27, 2022, 06:21:04 AM
post Re: Induction cooker without electronics
[Electronic Circuits]
klugesmith
November 27, 2022, 01:13:28 AM
post Re: Oh Lawd, I got dem Op-Amp blues!
[General Chat]
AkashaStar
November 26, 2022, 06:49:16 PM
post Re: ZVS driver won't oscillate
[Electronic Circuits]
AstRii
November 26, 2022, 04:48:39 PM
post Re: IF D95T vs IF D95OC
[Dual Resonant Solid State Tesla coils (DRSSTC)]
RoamingD
November 26, 2022, 06:56:51 AM
post Re: IF D95T vs IF D95OC
[Dual Resonant Solid State Tesla coils (DRSSTC)]
alexhanyuan
November 25, 2022, 11:28:15 PM
post Re: Induction cooker without electronics
[Electronic Circuits]
Solhi
November 25, 2022, 12:05:50 PM
post Re: Induction cooker without electronics
[Electronic Circuits]
Solhi
November 25, 2022, 07:53:52 AM
post Re: Induction cooker without electronics
[Electronic Circuits]
Solhi
November 24, 2022, 08:08:48 AM
post Re: EEFL backlight circuits
[Light, Lasers and Optics]
klugesmith
November 24, 2022, 07:26:49 AM
post Re: Air cored inductors proximity to conductive objects
[General Chat]
davekni
November 24, 2022, 03:02:11 AM
post Re: Solid State “rheostat” that will withstand high electrostatic fields
[General Chat]
AkashaStar
November 24, 2022, 02:25:42 AM
post Re: Induction cooker without electronics
[Electronic Circuits]
Solhi
November 24, 2022, 01:45:33 AM
post Re: Air cored inductors proximity to conductive objects
[General Chat]
John123
November 23, 2022, 11:27:18 PM
post Stepper motor drive without switching
[Electronic Circuits]
klugesmith
November 23, 2022, 10:23:07 PM
post Re: Air cored inductors proximity to conductive objects
[General Chat]
Twospoons
November 23, 2022, 09:29:01 AM
post Re: Vacuum pump
[Laboratories, Equipment and Tools]
Alberto
November 23, 2022, 08:45:37 AM
post Re: Air cored inductors proximity to conductive objects
[General Chat]
davekni
November 23, 2022, 04:44:20 AM
post Air cored inductors proximity to conductive objects
[General Chat]
John123
November 23, 2022, 01:10:17 AM
post Re: Post-Soviet Tesla Coil Teardown and Test
[Solid State Tesla Coils (SSTC)]
Mads Barnkob
November 22, 2022, 08:40:19 PM
post Re: Ericsson RBS 6601 RRUS 12 analysis(kind of)
[Electronic Circuits]
Da_Stier
November 22, 2022, 08:22:09 PM
post Re: Ericsson RBS 6601 RRUS 12 analysis(kind of)
[Electronic Circuits]
Kirby4life
November 22, 2022, 08:45:06 AM
post Ericsson RBS 6601 RRUS 12 analysis(kind of)
[Electronic Circuits]
RickNitro
November 22, 2022, 08:36:11 AM
post Re: Vacuum pump
[Laboratories, Equipment and Tools]
davekni
November 22, 2022, 06:42:31 AM
post Re: Vacuum pump
[Laboratories, Equipment and Tools]
Twospoons
November 22, 2022, 06:40:32 AM
post Re: Vacuum pump
[Laboratories, Equipment and Tools]
klugesmith
November 22, 2022, 04:53:40 AM
post Re: Vacuum pump
[Laboratories, Equipment and Tools]
Twospoons
November 22, 2022, 02:17:08 AM
post Re: Vacuum pump
[Laboratories, Equipment and Tools]
klugesmith
November 21, 2022, 11:03:04 PM
post Re: Vacuum pump
[Laboratories, Equipment and Tools]
Alberto
November 21, 2022, 09:55:02 PM
post Re: Induction cooker without electronics
[Electronic Circuits]
Solhi
November 21, 2022, 03:09:26 PM
post Re: Post-Soviet Tesla Coil Teardown and Test
[Solid State Tesla Coils (SSTC)]
LoOdaK
November 21, 2022, 09:38:22 AM
post Re: Trichel pulses
[Electronic Circuits]
klugesmith
November 20, 2022, 10:05:15 PM
post Trichel pulses
[Electronic Circuits]
haversin
November 20, 2022, 09:48:37 PM
post Re: Induction cooker without electronics
[Electronic Circuits]
klugesmith
November 20, 2022, 07:17:36 PM
post Re: Some questions about my first drsstc.
[Dual Resonant Solid State Tesla coils (DRSSTC)]
mthome4
November 20, 2022, 02:28:22 PM
post Post-Soviet Tesla Coil Teardown and Test
[Solid State Tesla Coils (SSTC)]
Mads Barnkob
November 20, 2022, 02:03:49 PM
post Re: Induction cooker without electronics
[Electronic Circuits]
Solhi
November 20, 2022, 10:00:13 AM
post Re: TV flyback number of primary turns rule of thumb
[Transformer (Ferrite Core)]
davekni
November 20, 2022, 05:13:12 AM
post Re: Plasma Toroid
[Solid State Tesla Coils (SSTC)]
davekni
November 20, 2022, 05:08:31 AM
post Re: Plasma Toroid
[Solid State Tesla Coils (SSTC)]
alan sailer
November 20, 2022, 01:27:00 AM
post Re: Basic Gate driving doubts
[Solid State Tesla Coils (SSTC)]
davekni
November 19, 2022, 10:12:14 PM
post Re: TV flyback number of primary turns rule of thumb
[Transformer (Ferrite Core)]
John123
November 19, 2022, 09:57:35 PM
post Re: Basic Gate driving doubts
[Solid State Tesla Coils (SSTC)]
prabhatkumar
November 19, 2022, 09:50:23 PM
post Re: Basic Gate driving doubts
[Solid State Tesla Coils (SSTC)]
davekni
November 19, 2022, 08:26:45 PM
post Re: Vacuum pump
[Laboratories, Equipment and Tools]
davekni
November 19, 2022, 06:53:17 PM
post Re: Vacuum pump
[Laboratories, Equipment and Tools]
klugesmith
November 19, 2022, 06:05:47 PM
post Re: Vacuum pump
[Laboratories, Equipment and Tools]
Alberto
November 19, 2022, 05:34:46 PM
post Re: Induction cooker without electronics
[Electronic Circuits]
Solhi
November 19, 2022, 02:30:04 PM
post Re: Welcome new members, come say hello and tell a little about yourself :)
[General Chat]
AkashaStar
November 19, 2022, 01:56:10 PM
post Re: Buck converter question
[Dual Resonant Solid State Tesla coils (DRSSTC)]
dru
November 19, 2022, 08:03:56 AM
post Re: Induction cooker without electronics
[Electronic Circuits]
Solhi
November 19, 2022, 06:38:00 AM
post Basic Gate driving doubts
[Solid State Tesla Coils (SSTC)]
prabhatkumar
November 19, 2022, 05:37:09 AM
post Re: ZVS driver won't oscillate
[Electronic Circuits]
davekni
November 19, 2022, 03:59:56 AM
post Re: Non-laser pointer
[Light, Lasers and Optics]
klugesmith
November 19, 2022, 03:56:32 AM
post Re: Buck converter question
[Dual Resonant Solid State Tesla coils (DRSSTC)]
davekni
November 19, 2022, 03:36:20 AM
post Re: Vacuum pump
[Laboratories, Equipment and Tools]
davekni
November 19, 2022, 03:26:48 AM
post Re: Vacuum pump
[Laboratories, Equipment and Tools]
Alberto
November 19, 2022, 12:40:33 AM
post Re: ZVS driver won't oscillate
[Electronic Circuits]
AstRii
November 18, 2022, 09:32:33 PM
post Re: Induction cooker without electronics
[Electronic Circuits]
klugesmith
November 18, 2022, 05:48:00 PM
post Re: Audio Modulated CRT Flyback Transformer Loud Sparks
[Transformer (Ferrite Core)]
John123
November 18, 2022, 03:49:12 PM
post Re: TV flyback number of primary turns rule of thumb
[Transformer (Ferrite Core)]
John123
November 18, 2022, 02:56:49 PM
post IF D95T vs IF D95OC
[Dual Resonant Solid State Tesla coils (DRSSTC)]
RoamingD
November 18, 2022, 01:44:38 PM
post Re: Induction cooker without electronics
[Electronic Circuits]
Solhi
November 18, 2022, 11:38:44 AM
post Non-laser pointer
[Light, Lasers and Optics]
klugesmith
November 18, 2022, 10:05:29 AM
post Re: Induction cooker without electronics
[Electronic Circuits]
klugesmith
November 18, 2022, 06:54:55 AM
post Re: Induction cooker without electronics
[Electronic Circuits]
Twospoons
November 18, 2022, 06:29:23 AM
post Buck converter question
[Dual Resonant Solid State Tesla coils (DRSSTC)]
dru
November 18, 2022, 06:10:52 AM
post Re: TV flyback number of primary turns rule of thumb
[Transformer (Ferrite Core)]
davekni
November 18, 2022, 05:53:15 AM
post Re: Induction cooker without electronics
[Electronic Circuits]
Solhi
November 18, 2022, 05:21:52 AM
post Re: Vacuum pump
[Laboratories, Equipment and Tools]
davekni
November 18, 2022, 04:00:04 AM
post Re: Vacuum pump
[Laboratories, Equipment and Tools]
alan sailer
November 17, 2022, 10:24:35 PM
post Re: TV flyback number of primary turns rule of thumb
[Transformer (Ferrite Core)]
John123
November 17, 2022, 08:30:00 PM
post Re: TV flyback number of primary turns rule of thumb
[Transformer (Ferrite Core)]
klugesmith
November 17, 2022, 07:28:16 PM
post Re: TV flyback number of primary turns rule of thumb
[Transformer (Ferrite Core)]
John123
November 17, 2022, 03:38:00 PM
post Re: TV flyback number of primary turns rule of thumb
[Transformer (Ferrite Core)]
davekni
November 17, 2022, 04:03:51 AM
post Re: what type of diode is better for make high voltage diode?
[Voltage Multipliers]
davekni
November 17, 2022, 03:57:40 AM

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