Author Topic: My completed 14-stage Cockroft-Walton voltage multiplier  (Read 10216 times)

Offline MRMILSTAR

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My completed 14-stage Cockroft-Walton voltage multiplier
« on: April 13, 2021, 09:35:51 PM »
After 6 months of work I have finally finished my Cockroft-Walton voltage multiplier. It is a half-wave design with 14-stages. The specifications are:

* 14-stages, half-wave, positive output, oil immersion
* 28 TDK doorknob capacitors, each with 1.7 nf rated for 30 KV
* Each diode string consists of 3 fast-recovery (100 ns) diodes in series, with each diode being rated for 20 KV and 30 ma
* HV power supply consists of 2 AC flyback transformers, inputs in parallel, outputs in parallel, driven by a ZVS circuit
* HV power supply output voltage is 15 KV peak AC with 30 volt, 10 amp LV DC power supply as input
* HV power supply charging frequency is 28 Khz
* LV DC power supply is a SMPS capable of 30 volts at 10 amps
* Designed output voltage for 750 microamp load is 387 KV to 415 KV
* Output streamer is approximately 32 cm in length with toroids
* Load resistance consists of 24 Ohmite resistors in series-parallel with each resistor rated for 2.5M ohms, 50 KV, 12.5 watts
* Composite load resistance spec is 6.8M ohms, 400 KV, 300 watts

There is a front panel DC voltmeter to ensure that the input voltage is between 15 and 30 volts before switching on the multiplier. This is to prevent the ZVS driver transistors from being damaged due to insufficient input voltage. There is a remote on-off switch so that you don't have to be too close when you switch it on.

The entire multiplier stack is housed in a 4" ID clear PVC tube filled with mineral oil. The load resistance and discharge tower operate in air. Everything was designed to be easily serviceable. I have already had to remove the multiplier stack from the tube for modification. Even with oil it wasn't that bad.

The peak AC input voltage to the multiplier stack was measured with a custom-made HV full-wave bridge rectifier that I made just for this purpose. A 2 nf smoothing capacitor is connected to the output of the rectifier. I then use a commercial HV DC probe with built-in voltmeter to measure the DC output voltage of the rectifier. This then is the peak voltage of the AC waveform. With this rectifier, which is removed after the measurement, I determined that a 30 volt DC input yields a 15 KV peak AC output from the flyback transformers.

I had to modify the ZVS driver slightly by adding an additional 0.66 uf of capacitance to the existing capacitance. Two extra 0.33 uf MKP capacitors identical to the six capacitors on the circuit board were used to do this. This was done without having to modify the circuit card by merely connecting the the two extra capacitors across the output terminals. The extra capacitors can be seen in the attached pictures as a small outboard auxiliary circuit card. Adding this extra capacitance increased the streamer length by amount 9 cm so it was a substantial improvement. This addition set the charging frequency at 28 Khz. This is similar to tuning a Tesla coil.

I must say that its sort of creepy to operate if you are within 4 feet of it. The HV DC charges everything that is close by. It makes all of the hair on your body try to stand up and it feels like your skin is crawling. Its like a Van De Graaff generator on steroids. I have to constantly discharge my body to avoid a big charge build-up. Maybe I need to start wearing a ground strap.

Another interesting observation involves optics. The capacitors and diodes are mounted on an acrylic carrier. Apparently, mineral oil and acrylic have an almost identical index of refraction. This causes the acrylic carrier to be almost invisible when immersed in oil. It appears as if the capacitors and diodes are suspended in the oil without support which looks interesting. The tubular shape of the clear PVC tube also acts as a sort of lens which magnifies and distorts the appearance of the capacitors and diodes.

Here are 2 links to Youtube videos from my Youtube channel. The first video is an overview. The second video shows it in operation.

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« Last Edit: March 25, 2022, 09:18:04 PM by MRMILSTAR »
Steve White
Cedar Rapids, Iowa
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Re: My 14-stage Cockroft-Walton voltage multiplier
« Reply #1 on: April 13, 2021, 09:47:39 PM »
Nice craftsmanship!  Looks like you are set for a museum display.
David Knierim

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Re: My 14-stage Cockroft-Walton voltage multiplier
« Reply #2 on: April 13, 2021, 10:17:24 PM »
Nice craftsmanship!  Looks like you are set for a museum display.

Thanks Dave! Half the fun of building these projects for me is making them to a high standard of craftsmanship so it takes me a long time to complete these things.
« Last Edit: April 13, 2021, 10:47:34 PM by MRMILSTAR »
Steve White
Cedar Rapids, Iowa
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Re: My 14-stage Cockroft-Walton voltage multiplier
« Reply #3 on: April 14, 2021, 10:03:39 AM »
Hi Steve,

Great work you have done. I really like the construction techniques you have done here 👍.
And I can understand the amount of time this takes. Very cool 😎.
I watched these 2 videos of this great fella. Looked to see what else you possibly had also, and watched all the videos of other great stuff also, that were recently uploaded too.
👍 Up again...

Kinda of related, to good construction techniques, fairly recently, I have finally decided and have been planning and starting on finalizing my 304er VTTC. Only been, oh I think about 3-4 years now of "heavy" changing around and experimenting with it... decided it is time...I still remember quite a while ago, you mentioning about possibly doing a final setup of it.
Going to take a bit here, just about have everything I need.
Will get around to doing some posts on it.

Again... great job here... 🤓

Chris Reeland
Ladd Illinois USA
Chris Reeland
Ladd Illinois USA
Former Printer

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Re: My 14-stage Cockroft-Walton voltage multiplier
« Reply #4 on: April 14, 2021, 10:31:23 AM »

I must say that its sort of creepy to operate if you are within 4 feet of it. The HV DC charges everything that is close by. It makes all of the hair on your body try to stand up and it feels like your skin is crawling. Its like a Van De Graaf generator on steroids. I have to constantly discharge my body to avoid a big charge build-up. Maybe I need to start wearing a ground strap.


Hi Steve again,

I think I can relate to this experience some... being a former printer on old large newspaper printing presses...on dry air days during the winter time...the press in certain areas would charge up. You could feel this in your whole body in this charge field. Quite the strange feeling. Some areas of the press would also discharge arcs at times 3-4 foot long! Quite scary up close! Glad I never got hit!
We also at times..."goofed off" a little with these charge fields...we would "touch" a co-worker. Did not really touch for real...a arc would jump that was typically 3-4 inches long...once near enough. This hurt like hell for the both of us. So in actuality...we did not goof too much...since the mischievous person got it too...

Chris Reeland
Ladd Illinois USA
Chris Reeland
Ladd Illinois USA
Former Printer

Offline MRMILSTAR

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Re: My 14-stage Cockroft-Walton voltage multiplier
« Reply #5 on: April 14, 2021, 03:51:36 PM »
Chris, thanks for the kind words! Here are a few detailed in-progress construction pictures of the voltage multiplier which I didn't originally post because I thought they were too detailed. These pictures show how the multiplier stack makes electrical contact with the HV AC power supply. I wrestled with this problem for a long time. The main problem was that the multiplier stack was to be immersed in oil. So how to make a good electrical contact without oil leaking out and also allowing the multiplier stack to be easily removed for service? I hope that these pictures clarify that.

There are two copper contact plates at the bottom of the tube which are fixed and attached to a GP03 carrier (red material). Each contact is connected to a through-hole screw terminal like you see on commercial power supplies. Each through-hole terminal is screwed into a tapped threaded hole in the bottom of the PVC base. The bottom of the multiplier stack has two spring-loaded electrodes. When the stack is lowered into position the spring electrodes make contact with the copper contact plates mounted on the base. There is a horizontal slot that I machined into the GP03 carrier between the two copper contact plates. There is a matching acrylic bar at the bottom of the multiplier stack. The slot-and-bar arrangement acts as a lock-and-key which allows positive alignment to be made between the spring-loaded electrodes and the fixed copper plates. The slot-and-bar arrangement also allows me to do this blindly by feel since I can't see to the bottom of the multiplier stack tube when I'm lowering the stack into the tube. The slot and bar also lock into place and prevents the electrodes from rotating out of alignment. The acrylic bar on the bottom of the multiplier stack also limits the compression depth of the springs so that they are not crushed by the weight of the multiplier stack.

I poured slow-cure (24 hours) 2-part epoxy resin, which flows easily, into the bottom of the base mount up to the level of the bottom of the machined slot between the fixed copper plates. The resin flowed all around the threads and holes of the through-hole screw terminals thus sealing these holes against any oil leakage to the outside. I haven't observed any sign of oil leakage. As an unplanned test I've had to pull the multiplier stack out of the oil-filled tube once for modifications and indeed this system worked well. Service was easy and I was able to lower the stack blindly back into the tube by feel into proper alignment.

There's also some custom PVC supports shown here. I hope that this description made sense.
« Last Edit: May 01, 2021, 04:44:52 PM by MRMILSTAR »
Steve White
Cedar Rapids, Iowa
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Re: My 14-stage Cockroft-Walton voltage multiplier
« Reply #6 on: April 14, 2021, 07:34:33 PM »
Quote
We also at times..."goofed off" a little with these charge fields...we would "touch" a co-worker. Did not really touch for real...a arc would jump that was typically 3-4 inches long...once near enough. This hurt like hell for the both of us. So in actuality...we did not goof too much...since the mischievous person got it too...

At least for smaller static sparks, if you reach out towards someone with a metal object (piece of foil, key, ...) in your hand, then you will feel little of the shock.  The metal object spreads out the current across a much larger area of skin.  I make use of this regularly when stepping out of my car on dry days.  A firm grip on the inside door handle (metal) while stepping out avoids me feeling any of the shock.
David Knierim

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Re: My 14-stage Cockroft-Walton voltage multiplier
« Reply #7 on: April 14, 2021, 07:42:50 PM »
Hi Steve,

Thanks for some more details and pictures of the electrical connections. Like this a lot.

I have just downloaded all 21 pictures, so I can study them further, closely examing all I can see. I enjoy studying all kinds of details of great construction.

Chris
Chris Reeland
Ladd Illinois USA
Former Printer

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Re: My 14-stage Cockroft-Walton voltage multiplier
« Reply #8 on: April 14, 2021, 07:54:38 PM »
Hi David,

I will have to keep that in mind if ever in this situation ever again 😁.

But unfortunately 🤕, I am no longer a Printer anymore...not by choice...they are all gone, the presses, in a very large area...just big city presses left. All smaller newspapers have given up on presses. It is farmed out. Even some fairly large newspapers and newspaper groups, have given up on their own presses. Changing world...

So after 25-30 years...I had to change careers.
I will always have some ink in my blood though...

Chris

Chris Reeland
Ladd Illinois USA
Former Printer

Offline MRMILSTAR

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Re: My 14-stage Cockroft-Walton voltage multiplier
« Reply #9 on: April 14, 2021, 09:34:11 PM »
Hi Steve,

Thanks for some more details and pictures of the electrical connections. Like this a lot.

I have just downloaded all 21 pictures, so I can study them further, closely examing all I can see. I enjoy studying all kinds of details of great construction.

Chris

I attached 2 more pictures at the end of the original post if you want them.
Steve White
Cedar Rapids, Iowa
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Re: My 14-stage Cockroft-Walton voltage multiplier
« Reply #10 on: April 14, 2021, 10:56:15 PM »
Here's the full-wave bridge rectifier that I built to measure the output of the two AC flyback transformers. Each leg consist of two fast 20 KV diodes in series. The smoothing capacitor is 2 nf rated for 30 KV. The voltmeter is a commercial HV DC unit rated for 40 KV. The measurement is the peak AC voltage output of the flybacks minus a small amount of voltage droop.
« Last Edit: November 06, 2021, 10:14:32 PM by MRMILSTAR »
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Re: My 14-stage Cockroft-Walton voltage multiplier
« Reply #11 on: April 30, 2021, 04:55:18 PM »
A beautiful project! Looks very professional and neatly finished. Thank you very much for sharing!

Best regards
kilovolt  ;)
All information on my part without guarantee! I reject any liability for personal and/or material damage. Everyone is responsible for his own safety.

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Re: My 14-stage Cockroft-Walton voltage multiplier
« Reply #12 on: April 30, 2021, 11:36:20 PM »
Thanks kilovolt!
Steve White
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Re: My 14-stage Cockroft-Walton voltage multiplier
« Reply #13 on: May 17, 2021, 08:50:26 PM »
Very impressive build , looks really good ^^ .

I like how the multiplier joins as the base with the flat plates to provide the connection .

When you calculate the output resistance needed , is this simply the expected output voltage divided by the target current you need ?

Cheers

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Re: My 14-stage Cockroft-Walton voltage multiplier
« Reply #14 on: May 17, 2021, 10:29:06 PM »
Very impressive build , looks really good ^^ .

When you calculate the output resistance needed , is this simply the expected output voltage divided by the target current you need ?

Cheers

Thanks DashApple. You must have a load resistance or you will probably burn out the diodes. Its a combination of Ohms's law, what sort of HV power resistors that you can buy for a reasonable price, and the diode current rating. Its also a function of what you are trying to accomplish. I just wanted to generate streamers. Its a trade-off.

The design can supply 750 ua at about 400 KV. Using those specs yields a desired load resistance of about 500M ohms rated for about 300 watts and 400 KV. This would have yielded an uninterrupted streamer of about 30 cm. I couldn't find any resistors for a reasonable price that would yield that combination.

What I could find for a reasonable price is the resistor combination that I have. The 6.3M ohms loads down the generator more than 750 ua so the streamer is constantly interrupted and is re-established as the voltage drops below that needed to bridge the 30 cm. This causes the crackling sound even though it looks continuous. A continuous DC streamer would make very little noise. Moving the toroids closer together makes the streamer more continuous and quieter because a lower voltage is needed to bridge the toroids.

The 6.3M ohms load draws about 60 ma which is actually beyond the steady-state 30 ma rating of my diodes. They have a surge rating of 1 amp however. So far the diodes have held up. If I blow any I will replace them with fast 100 ma diodes.
« Last Edit: May 17, 2021, 10:37:06 PM by MRMILSTAR »
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Re: My completed 14-stage Cockroft-Walton voltage multiplier
« Reply #15 on: June 29, 2021, 09:51:13 PM »
So, dumb question alert.

With the AC flybacks putting out 15kV peak and 14 stages of multiplier how do you get 400kV?

Years ago I built a 40kV supply for a high speed flash and used a 7kV neon sign transformer. I used a four stage multiplier.
Minus some losses I got just what the math said 7*4*1.141= ~39kV.

Also I am curious what the final supply was intended for. It would make a great power supply for an electron accelerator...

Cheers.

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Re: My completed 14-stage Cockroft-Walton voltage multiplier
« Reply #16 on: June 29, 2021, 10:29:52 PM »
Determining a CW VM output is always a challenge. On a  lossless idealized basis with 14 capacitors you arrive at

15,000 volts * 14 capacitor pairs * 2 = 420 KV at rated current (750 ua)

Of coarse there are losses. I used a design program which accounts for losses. It states that the output due to ripple is 385 to 416 KV at the rated current of 750 ua. I take the average to be about 400 KV.

Now if your load resistance draws more current than the design current, then the voltage will continuously sag and re-establish many times per second depending on the charging frequency. My load resistance draws much more current than 750 ua. As a result, the streamers disappear as the voltage sags below the minimum necessary to draw a streamer across 32 cm of air. The capacitors then re-charge and re-establish the streamer. This dropping and re-establishing of the streamer many times per second causes the crackling sound even though the streamer looks continuous. If my load only drew a maximum of 750 ua, the streamer would be continuous and be almost silent.

Finally, we can use the streamer length to estimate the voltage. Large spheres or flat plates as electrodes require about 3000 volts/mm to bridge the gap. This would indicate an output voltage of 960 KV which is obviously not correct. Pointy electrodes require about 1000 volts/mm to bridge the gap. This would indicate an output voltage of 320 KV. My small toroids are somewhere between a pointy electrode and a large sphere. This places the range between 320 KV and 960 KV. This leads me to believe that the design program estimate of 385 KV to 416 KV is correct.

My only application for the multiplier is just to draw long streamers for physics demonstrations.

By the way, the math says that your output should have been about 78 KV. You forgot to multiply by 2. A NST is not a very good power supply for a VM because it only operates at 60 Hz. You would need huge capacitors to get any kind of output with decent ripple. Maybe you only estimated 39 KV because your voltage ripple was so high.
« Last Edit: July 26, 2021, 09:29:50 PM by MRMILSTAR »
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Re: My completed 14-stage Cockroft-Walton voltage multiplier
« Reply #17 on: June 29, 2021, 10:50:02 PM »
Thanks again. Making big sparks to demonstrate something is the point of nearly all tesla coils.

And having fun building them of course. I was kind of shocked to realize while building my first DRSSTC
(my tenth or so coil) that I don't like running the damn things, just building them.

I am unfamiliar with the factor of two. I also measured the output of the supply with one of those
Fluke 40kV DC probes. It all added up like I described.

I now own an AC Tek 40kV probe so maybe I will go back and see about the ripple. But maybe I'll let inertia win.

My current requirements were pretty minimal so I charged he capacitor on my flash through a
300Mohm resistor. Since the cap was only 40nF the charging  time was slow but I was only firing
the flash every few minutes.

Cheers.

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Re: My completed 14-stage Cockroft-Walton voltage multiplier
« Reply #18 on: June 29, 2021, 10:52:28 PM »
I also get a lot more fun out of building the HV projects than operating them. I usually only fire them up by request.

I suspect that your voltage ripple was so high that your Fluke DC probe and meter was only showing you something like an average between the DC maximum and minimum. That's why higher charging frequencies are better. Load the parameters for your VM into this design tool and see what it tells you.

https://www.extremeelectronics.co.uk/calculators/cw-voltage-calculator/
« Last Edit: June 29, 2021, 10:59:12 PM by MRMILSTAR »
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Re: My completed 14-stage Cockroft-Walton voltage multiplier
« Reply #19 on: November 24, 2021, 10:00:47 PM »
I added a very useful little circuit to my Cockroft-Walton voltage multiplier. Its a wireless remote switch. I was using a hard-wired remote switch to switch it on and off. With this wireless remote switch I only have to push the button on a FOB. This keeps me at a safe distance from the voltage multiplier when switching it on and off.

It consists of a buck converter and a 350 mhz RF switch. The buck converter reduces the 15 to 30 volts DC input for the voltage multiplier down to the 12 volts required by the wireless switch circuitry.

I was concerned that the intense electric field might damage the circuitry or affect its operation but everything operates as expected. I still have the option of using the hard-wired remote switch.

Here are some pictures.
« Last Edit: November 29, 2021, 09:05:19 PM by MRMILSTAR »
Steve White
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Re: My completed 14-stage Cockroft-Walton voltage multiplier
« Reply #19 on: November 24, 2021, 10:00:47 PM »

 


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[Voltage Multipliers]
Alberto
March 24, 2024, 07:27:24 PM
post Re: capacitor and diodes. Voltage values for a CW
[Voltage Multipliers]
MRMILSTAR
March 24, 2024, 04:25:23 AM
post Re: capacitor and diodes. Voltage values for a CW
[Voltage Multipliers]
Alberto
March 23, 2024, 10:47:35 PM
post Re: capacitor and diodes. Voltage values for a CW
[Voltage Multipliers]
MRMILSTAR
March 23, 2024, 09:30:21 PM
post Re: capacitor and diodes. Voltage values for a CW
[Voltage Multipliers]
Alberto
March 23, 2024, 04:34:31 PM
post Re: capacitor and diodes. Voltage values for a CW
[Voltage Multipliers]
MRMILSTAR
March 23, 2024, 03:04:25 PM
post Re: capacitor and diodes. Voltage values for a CW
[Voltage Multipliers]
Alberto
March 23, 2024, 01:38:34 PM
post Re: capacitor and diodes. Voltage values for a CW
[Voltage Multipliers]
MRMILSTAR
March 23, 2024, 04:20:03 AM
post Re: Welcome new members, come say hello and tell a little about yourself :)
[General Chat]
davekni
March 23, 2024, 12:54:30 AM
post Re: Smoke Screen Machine Protect 950 XP - Teardown of a Smoke Cannon!
[Electronic Circuits]
davekni
March 23, 2024, 12:05:57 AM
post capacitor and diodes. Voltage values for a CW
[Voltage Multipliers]
Alberto
March 22, 2024, 11:45:03 PM
post Re: Welcome new members, come say hello and tell a little about yourself :)
[General Chat]
OmGigaTron
March 22, 2024, 11:30:09 PM
post Smoke Screen Machine Protect 950 XP - Teardown of a Smoke Cannon!
[Electronic Circuits]
Mads Barnkob
March 22, 2024, 10:20:35 PM
post Re: Where's all this voltage coming from?
[Spark Gap Tesla Coils (SGTC)]
Benbmw
March 22, 2024, 09:21:13 PM
post Re: What actually kills MOSFETs?
[Beginners]
AstRii
March 22, 2024, 03:37:11 PM
post What actually kills MOSFETs?
[Beginners]
FPS
March 22, 2024, 05:09:20 AM
post Re: Benjamin's DRSSTC 2 in progress
[Dual Resonant Solid State Tesla coils (DRSSTC)]
Benjamin Lockhart
March 22, 2024, 03:57:54 AM
post Re: Benjamin's DRSSTC 2 in progress
[Dual Resonant Solid State Tesla coils (DRSSTC)]
davekni
March 22, 2024, 02:59:25 AM
post Re: Benjamin's DRSSTC 2 in progress
[Dual Resonant Solid State Tesla coils (DRSSTC)]
Benjamin Lockhart
March 21, 2024, 06:31:42 PM
post Re: 2x Panasonic Inverter Microwaves - what to salvage, dangers?
[General Chat]
rikkitikkitavi
March 21, 2024, 03:08:01 PM
post Re: [WTS] IGBT, Ferrite, Capacitors, Tools, PSU, Industrial components and parts
[Sell / Buy / Trade]
Mads Barnkob
March 21, 2024, 01:37:32 PM
post Re: Difference between these transformers
[Transformer (Ferrite Core)]
Alberto
March 21, 2024, 11:42:07 AM
post Re: Phase Lead Questions
[Dual Resonant Solid State Tesla coils (DRSSTC)]
davekni
March 21, 2024, 04:09:14 AM
post Re: Benjamin's DRSSTC 2 in progress
[Dual Resonant Solid State Tesla coils (DRSSTC)]
Benjamin Lockhart
March 21, 2024, 02:15:31 AM
post My Homemade Structural Analysis X-Ray Machine
[X-ray]
Luca c.
March 21, 2024, 01:35:40 AM
post Re: Phase Lead Questions
[Dual Resonant Solid State Tesla coils (DRSSTC)]
Saattvik24
March 20, 2024, 10:40:00 PM
post Re: Difference between these transformers
[Transformer (Ferrite Core)]
Mads Barnkob
March 20, 2024, 08:03:41 PM
post Re: 2x Panasonic Inverter Microwaves - what to salvage, dangers?
[General Chat]
Mads Barnkob
March 20, 2024, 07:51:57 PM
post Re: Benjamin's DRSSTC 2 in progress
[Dual Resonant Solid State Tesla coils (DRSSTC)]
Mads Barnkob
March 20, 2024, 10:39:47 AM
post Re: Phase Lead Questions
[Dual Resonant Solid State Tesla coils (DRSSTC)]
davekni
March 20, 2024, 04:09:59 AM
post Re: 160mm DRSSTC II project | Questions
[Dual Resonant Solid State Tesla coils (DRSSTC)]
Benjamin Lockhart
March 20, 2024, 01:13:23 AM
post Re: Phase Lead Questions
[Dual Resonant Solid State Tesla coils (DRSSTC)]
Keybored
March 20, 2024, 12:45:16 AM
post Re: Benjamin's DRSSTC 2 in progress
[Dual Resonant Solid State Tesla coils (DRSSTC)]
flyingperson23
March 20, 2024, 12:30:30 AM
post Re: Benjamin's DRSSTC 2 in progress
[Dual Resonant Solid State Tesla coils (DRSSTC)]
Benjamin Lockhart
March 19, 2024, 11:12:24 PM
post Re: 160mm DRSSTC II project | Questions
[Dual Resonant Solid State Tesla coils (DRSSTC)]
Late
March 19, 2024, 09:47:49 PM
post Re: 160mm DRSSTC II project | Questions
[Dual Resonant Solid State Tesla coils (DRSSTC)]
Late
March 19, 2024, 09:44:19 PM
post Phase Lead Questions
[Dual Resonant Solid State Tesla coils (DRSSTC)]
Saattvik24
March 19, 2024, 06:52:09 PM
post Re: 160mm DRSSTC II project | Questions
[Dual Resonant Solid State Tesla coils (DRSSTC)]
flyingperson23
March 19, 2024, 05:02:44 PM
post Re: Welcome new members, come say hello and tell a little about yourself :)
[General Chat]
Mads Barnkob
March 19, 2024, 05:01:41 PM
post Re: Benjamin's DRSSTC 2 in progress
[Dual Resonant Solid State Tesla coils (DRSSTC)]
Mads Barnkob
March 19, 2024, 04:31:02 PM
post Re: 160mm DRSSTC II project | Questions
[Dual Resonant Solid State Tesla coils (DRSSTC)]
Mads Barnkob
March 19, 2024, 03:59:54 PM
post Re: Benjamin's DRSSTC 2 in progress
[Dual Resonant Solid State Tesla coils (DRSSTC)]
Benjamin Lockhart
March 19, 2024, 06:41:39 AM
post Re: Welcome new members, come say hello and tell a little about yourself :)
[General Chat]
davekni
March 19, 2024, 04:05:49 AM
post Re: Welcome new members, come say hello and tell a little about yourself :)
[General Chat]
OmGigaTron
March 18, 2024, 09:08:35 PM
post Re: Can I Trust This Super Cheap Site?
[General Chat]
2020-Man
March 18, 2024, 09:07:35 PM
post Re: Can I Trust This Super Cheap Site?
[General Chat]
Twospoons
March 18, 2024, 08:57:06 PM
post Re: Can I Trust This Super Cheap Site?
[General Chat]
MRMILSTAR
March 18, 2024, 03:51:33 PM
post Re: 160mm DRSSTC II project | Questions
[Dual Resonant Solid State Tesla coils (DRSSTC)]
Late
March 18, 2024, 02:59:46 PM
post Re: 160mm DRSSTC II project | Questions
[Dual Resonant Solid State Tesla coils (DRSSTC)]
Late
March 18, 2024, 02:33:25 PM
post Can I Trust This Super Cheap Site?
[General Chat]
2020-Man
March 18, 2024, 11:02:12 AM
post Re: Where's all this voltage coming from?
[Spark Gap Tesla Coils (SGTC)]
Twospoons
March 18, 2024, 02:36:11 AM
post Re: Best forum for vacuum tube amplifiers?
[General Chat]
Mads Barnkob
March 17, 2024, 07:42:55 PM
post Re: 2x Panasonic Inverter Microwaves - what to salvage, dangers?
[General Chat]
Michelle_
March 17, 2024, 04:15:14 PM
post Re: 2x Panasonic Inverter Microwaves - what to salvage, dangers?
[General Chat]
Michelle_
March 17, 2024, 05:05:04 AM
post Re: Where's all this voltage coming from?
[Spark Gap Tesla Coils (SGTC)]
davekni
March 17, 2024, 04:50:51 AM
post Re: 2x Panasonic Inverter Microwaves - what to salvage, dangers?
[General Chat]
Twospoons
March 17, 2024, 04:45:17 AM
post 2x Panasonic Inverter Microwaves - what to salvage, dangers?
[General Chat]
Michelle_
March 17, 2024, 04:17:51 AM
post Where's all this voltage coming from?
[Spark Gap Tesla Coils (SGTC)]
Terry
March 17, 2024, 01:29:32 AM
post Re: DRSSTC Questions
[Dual Resonant Solid State Tesla coils (DRSSTC)]
flyingperson23
March 17, 2024, 12:33:06 AM
post Re: DRSSTC Questions
[Dual Resonant Solid State Tesla coils (DRSSTC)]
Keybored
March 16, 2024, 08:46:20 PM
post Re: Bleeder resistor for MMC
[Dual Resonant Solid State Tesla coils (DRSSTC)]
Hydron
March 16, 2024, 08:39:24 PM
post Re: DRSSTC Questions
[Dual Resonant Solid State Tesla coils (DRSSTC)]
Hydron
March 16, 2024, 08:21:44 PM
post Best forum for vacuum tube amplifiers?
[General Chat]
yourboi
March 16, 2024, 08:20:13 PM

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