Author Topic: Small DRSSTC Questions  (Read 1595 times)

Offline Mike

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Small DRSSTC Questions
« on: May 20, 2022, 12:43:36 PM »
Hi all,

I recently built my first DRSSTC to moderate success, I'm able to get just over 0.5m streamers with a 32us pulse width. What I'm finding confusing however is that when I increase the pulse width beyond about 40us the streamer length suddenly reduces to about 0.2m and stays constant as I increase the pulse width all the way to the current maximum of 64us. I'm using a UD2.7 driver and JavaTC output has been checked against measurements of secondary inductance & resistance and primary & secondary resonant frequencies, all appear in good agreement (full text output from JavaTC is below).

I've so far tried increasing the amount of film capacitance right on the bridge, and running in burst mode both working on the assumption that there might be too much impedance between my bulk cap and the bridge, but to no avail. Scoping the coil is a little tricky as I only have a 2 channel scope,  and don't currently have any ferrites to make a second CT, though as I'm not currently hitting over current protection, I could probably repurpose that...

Not sure if it's relevant at all, but when I lift the coil further from the ground the output steamers are about the same size but are more likely to hiss and crackle, vs when the coil sits on the ground it is a much purer tone coming from the coil. I assume this is due to the reduced secondary capacitance pulling the secondary out of tune.

If anyone has any ideas for things I could try or has heard of a similar issue before I'd really appreciate your feedback. Thanks!

J A V A T C version 13.6 - CONSOLIDATED OUTPUT
20/05/2022, 10:32:43 pm

Units = Centimeters
Ambient Temp = 20ºC

----------------------------------------------------
Surrounding Inputs:
----------------------------------------------------
200 = Ground Plane Radius
200 = Wall Radius
200 = Ceiling Height

----------------------------------------------------
Secondary Coil Inputs:
----------------------------------------------------
Current Profile = G.PROFILE_LOADED
4 = Radius 1
4 = Radius 2
15 = Height 1
50 = Height 2
1500 = Turns
0.02 = Wire Diameter

----------------------------------------------------
Primary Coil Inputs:
----------------------------------------------------
Round Primary Conductor
5.5 = Radius 1
18 = Radius 2
16 = Height 1
16 = Height 2
6.5 = Turns
0.6 = Wire Diameter
0 = Ribbon Width
0 = Ribbon Thickness
0.067 = Primary Cap (uF)
0 = Total Lead Length
0 = Lead Diameter

----------------------------------------------------
Secondary Coil Outputs:
----------------------------------------------------
211.12 [kHz] = Secondary Resonant Frequency
90 [deg °] = Angle of Secondary
35 [cm] = Length of Winding
42.86 [cm] = Turns Per Unit
0.03333 [mm] = Space Between Turns (edge to edge)
376.99 [m] = Length of Wire
4.38 [:1] = H/D Aspect Ratio
205.2 [Ohms] = DC Resistance
47547 [Ohms] = Reactance at Resonance
0.105 [ kg] = Weight of Wire
35.844 [mH] = Les-Effective Series Inductance
37.814 [mH] = Lee-Equivalent Energy Inductance
37.041 [mH] = Ldc-Low Frequency Inductance
15.855 [pF] = Ces-Effective Shunt Capacitance
15.029 [pF] = Cee-Equivalent Energy Capacitance
25.403 [pF] = Cdc-Low Frequency Capacitance
0.165 [mm] = Skin Depth
12.848 [pF] = Topload Effective Capacitance
273.0364 [Ohms] = Effective AC Resistance
174 [Q] = Quality Factor

----------------------------------------------------
Primary Coil Outputs:
----------------------------------------------------
196.11 [kHz] = Primary Resonant Frequency
7.11 [% high] = Percent Detuned
0 [deg °] = Angle of Primary
479.88 [cm] = Length of Wire
2.93 [mOhms] = DC Resistance
1.323 [cm] = Average spacing between turns (edge to edge)
1.19 [ cm] = Proximity between coils
0 [cm] = Recommended minimum proximity between coils
9.83 [µH] = Ldc-Low Frequency Inductance
0.05781 [µF] = Cap size needed with Primary L (reference)
0 [µH] = Lead Length Inductance
91.947 [µH] = Lm-Mutual Inductance
0.152 [k] = Coupling Coefficient
0.126 [k] = Recommended Coupling Coefficient
6.58 [half cycles] = Number of half cycles for energy transfer at K
16.53 [µs] = Time for total energy transfer

----------------------------------------------------
Top Load Inputs:
----------------------------------------------------
Toroid #1: minor=8, major=30, height=52, topload
« Last Edit: August 11, 2022, 05:39:31 AM by Mike »

Offline AstRii

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Re: DRSSTC streamers shrink with increasing pulse width
« Reply #1 on: May 20, 2022, 05:05:40 PM »
Check your secondary if it does not flash over on the inner side. Maybe after you increase ontime, the streamers break through the inner side of the secondary, that would explain lower output while increasing input power.
Marek Novotny
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Offline davekni

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Re: DRSSTC streamers shrink with increasing pulse width
« Reply #2 on: May 20, 2022, 08:23:46 PM »
Quote
Scoping the coil is a little tricky as I only have a 2 channel scope,  and don't currently have any ferrites to make a second CT, though as I'm not currently hitting over current protection, I could probably repurpose that...
Scoping would be useful and not that hard.  No need for a second CT.  Scope across R1 of UD2.7 (51 ohm feedback current sense burden resistor).  Presuming phase-lead is enabled (SV1 pins 2 and 3 are connected), SV1 pin 1 is a good place to scope, as it is connected to R1.  Initially, I'd use current (R1 voltage) for one channel and one output pin of UD2.7 (GDT input) for the other channel.

As a second run, move the second probe to one side of H-bridge output.  Unless you have an isolation transformer feeding your coil, use a small capacitor (1-10nF) of sufficient voltage rating between scope probe ground clip and VBus.  Or, leave ground clip disconnected for this second probe.  Even though there will be line-frequency added to H-bridge output, the much higher frequency bridge switching events will be visible.

BTW, my first guess is that you need a little more detuning (reduced primary frequency).  However, that is just a wild guess without scope traces.  What enable repeat frequency are you using for these tests?  Also, what is your bus voltage and over-current setpoint?

Good luck!
« Last Edit: May 20, 2022, 08:27:14 PM by davekni »
David Knierim

Offline Mike

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Re: DRSSTC streamers shrink with increasing pulse width
« Reply #3 on: May 20, 2022, 11:23:19 PM »
Check your secondary if it does not flash over on the inner side. Maybe after you increase ontime, the streamers break through the inner side of the secondary, that would explain lower output while increasing input power.

This was a good theory, but I can confirm there is no internal flash over. The coil former is sealed and I monitored joint between the PVC and HDPE top cap and there's no arcing present anywhere near it .

Scoping would be useful and not that hard.  No need for a second CT.  Scope across R1 of UD2.7 (51 ohm feedback current sense burden resistor).  Presuming phase-lead is enabled (SV1 pins 2 and 3 are connected), SV1 pin 1 is a good place to scope, as it is connected to R1.  Initially, I'd use current (R1 voltage) for one channel and one output pin of UD2.7 (GDT input) for the other channel.

You're right, for some reason I had it stuck in my head that the driver was mains referenced, but of course it's isolated. I'll try and get those measurements in the next day or two, see what they show, thanks. I hadn't encountered the cap on earth lead trick before, clever.

Currently running a repeat rate of between 500 and 2000Hz. Lower gives significantly smaller streamers. Bus voltage is 325VDC and over current set point is set to 200A.

*Fixed auto correct errors, typing on mobile still sucks.
« Last Edit: May 20, 2022, 11:49:21 PM by miket6000 »

Offline davekni

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Re: DRSSTC streamers shrink with increasing pulse width
« Reply #4 on: May 21, 2022, 12:31:45 AM »
Quote
Currently running a repeat rate of between 500 and 2000Hz. Lower gives significantly smaller streamers.
I'd guess that you want lower rates and more detuning.  High repeat rates (high BPS) can lead to continuous-arc behavior (ionized air path remains from one pulse to the next), which typically makes shorter thicker arcs.  Especially at 2kHz.

Do you have a break-out point on top?  How long?  A breakout point allows more detuning while still starting an arc, which allows longer arcs before secondary frequency drops too far below primary frequency.
David Knierim

Offline Mike

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Re: DRSSTC streamers shrink with increasing pulse width
« Reply #5 on: May 21, 2022, 11:12:05 PM »
Ok, I managed to get into the garage and get the scope attached. It became painfully obvious that the current limit was preventing larger streamers. The point where the streamers shrunk is the same point where the current limit kicked in. I still don't know why the current limiter was resulting in smaller streamers than limiting the energy with the pulse width, however winding the current limit up resulted in larger streamers.

I haven't had a chance to play with the repetition rate yet but will look into that as well.

Scope traces are below. The current waveform is approximately 0.11V/A (462:1 CT and 51R burden resistor). The ground clip for the HV trace was left floating.

As to the other questions, yes there is a breakout point, it extends ~10cm beyond the edge of the top load.

« Last Edit: May 21, 2022, 11:14:53 PM by miket6000 »

Offline davekni

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Re: DRSSTC streamers shrink with increasing pulse width
« Reply #6 on: May 22, 2022, 12:09:21 AM »
Quote
Ok, I managed to get into the garage and get the scope attached. It became painfully obvious that the current limit was preventing larger streamers. The point where the streamers shrunk is the same point where the current limit kicked in.
Glad to hear of your success!

Quote
I still don't know why the current limiter was resulting in smaller streamers than limiting the energy with the pulse width, however winding the current limit up resulted in larger streamers.
I'm not thinking of any explanation either.  Perhaps someone else can offer possibilities.

Quote
Scope traces are below. The current waveform is approximately 0.11V/A (462:1 CT and 51R burden resistor). The ground clip for the HV trace was left floating.
Forgot to mention previously:  If no suitable Y-caps are available, connecting scope probe ground clips to safety ground of line power inside coil base box is better than leaving ground floating.  That provides some capacitance to line power and through rectifier diodes to Vbus.

Hopefully this is just an artifact of floating scope ground clip:  The bridge output trace shows some partial steps during primary current decay after enable ends.  If those are real, it would indicate IGBT gates are not held off sufficiently, which could lead to IGBT failure.  What circuit are you using between GDT outputs and gates?  Is it the standard resistor paralleled by diode?  Are the diodes fast-recovery or schottky?
David Knierim

Offline Mike

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Re: DRSSTC streamers shrink with increasing pulse width
« Reply #7 on: May 22, 2022, 01:30:18 AM »
Quote
What circuit are you using between GDT outputs and gates?  Is it the standard resistor paralleled by diode?  Are the diodes fast-recovery or schottky?
Yep, 10R resistors and a schottky for turn off.

After increasing the current limit to 300A and detuing the primary by a full turn (I was surprised it was this much) I'm now getting >0.6m streamers and ground strikes. I'll keep playing with further detuning to try and find the optimal operating point but I feel like I'm well on the way. I also modified the interrupter so I can drop the repetition rate down to 200Hz. I still find longer arcs up around 1kHz, beyond that they get thicker but not really longer.

Thank you very much for your help davekni, I feel I'm now well on the way and can just play with parameters. I'll set the scope up again at some stage to get a better view on whether those partial turn on's are real. If so I'll probably need a bridge redesign to improve the layout as I'm not sure there's much else that I could do to hold the gates off better.

Photo below shows >1m strike!
« Last Edit: May 22, 2022, 02:03:01 AM by miket6000 »

Offline davekni

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Re: DRSSTC streamers shrink with increasing pulse width
« Reply #8 on: May 22, 2022, 04:57:46 AM »
Quote
Photo below shows >1m strike!
Looks great!  Have fun playing with your new coil!
David Knierim

Offline Mike

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Re: DRSSTC streamers shrink with increasing pulse width
« Reply #9 on: May 25, 2022, 12:16:00 AM »
Looks great!  Have fun playing with your new coil!
I have been, now with video!

Offline Mike

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Re: Small DRSSTC Questions
« Reply #10 on: August 11, 2022, 06:12:48 AM »
Hi all, I have another question based on an observation playing with my coil.

At lower input voltages I see a current waveform exactly as expected, the current ramps up initially then drops down after a streamer forms and reduces the Q of the system (first image). At higher voltages however there's a "double bounce" in current where the current starts to ramp down (presumably because a streamer has started) but then ramps back up again (second image). The issue I have with this is that the second ramp up is hitting my maximum current limit (500A) and terminating the pulse. Mostly I'm just curious if anyone has any theories as to why the current would be larger in the second ramp up that it was in the first and what the cause could be.


Low Voltage (100VDC)


High Voltage (325VDC)

My best theory so far is that the streamer loading initially reduced the primary current until it brings the secondary into tune with the primary causing an increase in the energy being transferred and a corresponding increase in primary current. I'll attempt to adjust the tuning of the primary to see if this is the case in which case I might be able to balance the two effects and avoid hitting the current limit.

As a small aside I still notice the effect where setting the pulse width to the point where it disables at about the same time as the current limit is hit I see slightly larger streamers than if I increase the pulse width beyond that point and let the current limiter terminate the pulse 100% of the time. It's also clear that the primary impedance of my coil is a little on the low side for my bridge, just a small decrease in capacitance would make all the above a non-issue, but again, I'll need to wait for new caps. I think I'll do this anyway as the current 2p3s of 940C20P1K-F is already at its limit (the 500A limit already puts 6.6kV across a 6kV DC rated cap, though only briefly).

Cheers,
Mike.


 


Offline davekni

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Re: Small DRSSTC Questions
« Reply #11 on: August 11, 2022, 11:51:42 PM »
Quote
My best theory so far is that the streamer loading initially reduced the primary current until it brings the secondary into tune with the primary causing an increase in the energy being transferred and a corresponding increase in primary current. I'll attempt to adjust the tuning of the primary to see if this is the case in which case I might be able to balance the two effects and avoid hitting the current limit.
I see the same primary waveform shape.  At least two different phenomenon can cause similar waveforms.  First one is classic dual-resonant system behavior.  If the arc doesn't drain sufficient secondary energy, remaining secondary energy transfers back to primary.  Higher energy shows up as higher current and voltage.
Second phenomenon is close to your theory above.  However, the second primary current increase is after arc loading lowers secondary frequency to the point where energy transfer is hampered.  Primary current increases without a way to dissipate.  I'd guess this is what you are experiencing.

I see both in my DRSSTC.  More detuning will help (lower primary frequency) with the second cause.  However, that raises amplitude of first current peak before arc starts.  You may want to detune until the first peak barely doesn't trip OCD.  Of course, as you mentioned, a slightly higher primary impedance will likely help.

Quote
As a small aside I still notice the effect where setting the pulse width to the point where it disables at about the same time as the current limit is hit I see slightly larger streamers than if I increase the pulse width beyond that point and let the current limiter terminate the pulse 100% of the time.
Any chance D3 is missing or reversed in your UD2.7 driver?  (Presuming that's the driver you are using.)  That's a diode in the OCD circuit from comparitor to FF.  That could make OCD events keep driver disabled for longer than just to the next interrupt enable cycle.
David Knierim

Offline Mike

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Re: Small DRSSTC Questions
« Reply #12 on: August 12, 2022, 01:27:14 AM »
Thanks Dave,

I lowered the primary frequency further and once I could achieve breakout by increasing the pulse repetition rate to ~1kHz (which I assume allows the breakout point to heat sufficiently and ionises the air near the breakout point to enable initial breakout) I hit much better performance with streamers growing more than 20% beyond my previous max. Unfortunately this was too much for the MMC which promptly failed short circuit. Even more unfortunately I wasn't monitoring the current at the time because it requires removing the UD2.7 housing which I was suspicious could be contributing to some of the weirdness I was seeing (it wasn't).

Quote
Any chance D3 is missing or reversed in your UD2.7 driver?  (Presuming that's the driver you are using.)  That's a diode in the OCD circuit from comparitor to FF.  That could make OCD events keep driver disabled for longer than just to the next interrupt enable cycle.

D3 is correctly installed, so that's one culprit removed.

I'm now stuck waiting for new caps to arrive. I've elected to use the same 2p3s configuration of 100n caps, but upgraded from 940C20's to 942C20's. Hopefully the increased peak current rating helps. I might also scale the peak current back down to 450A to mitigate the over voltage issue until I get some new 4s3p boards made up.


Offline Mike

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Re: My Small DRSSTC
« Reply #13 on: December 27, 2022, 11:14:28 AM »
Hi all,

I've updated my coil to use the new UDFreewheeling controller detailed here: https://highvoltageforum.net/index.php?topic=2054.20. I thought I'd post the results here and when I get some proper scope captures do a proper update on the progress on the other thread (I need to improve my scope shielding to prevent ground strikes causing potential damage).

The first video shows a cold breakout point and "low" BPS which causes spontaneous breakout from the toroid. I stop quickly to increase the BPS and you can see once the breakout heats up the streamer can start early enough that there's insufficient voltage to breakout on the toroid (at least that's my theory so far). The second is taken with the target a little further away and the lights off.

The new controller has increased the maximum streamer length from approximately 1.2m to more than 1.5m which I'm pretty happy with so far. It achieves this while reducing the peak current from 600A down to 150A. Of course in my case I've been running the coil very out of tune so the initial matching is poor and prone to very high initial currents. I've barely started experimenting with the new controller so it will be interesting to see what it's capable of.



Offline davekni

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Re: Small DRSSTC Questions
« Reply #14 on: December 27, 2022, 07:20:55 PM »
Quote
I've updated my coil to use the new UDFreewheeling controller detailed here: https://highvoltageforum.net/index.php?topic=2054.20.
Nice performance!  I'd been wondering how your freewheeling project was going.

Quote
The first video shows a cold breakout point and "low" BPS which causes spontaneous breakout from the toroid. I stop quickly to increase the BPS and you can see once the breakout heats up the streamer can start early enough that there's insufficient voltage to breakout on the toroid (at least that's my theory so far).
Probably some combination of breakout heating and air above it heating.
David Knierim

Online Mads Barnkob

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Re: Small DRSSTC Questions
« Reply #15 on: December 27, 2022, 07:46:49 PM »
Quote
The first video shows a cold breakout point and "low" BPS which causes spontaneous breakout from the toroid. I stop quickly to increase the BPS and you can see once the breakout heats up the streamer can start early enough that there's insufficient voltage to breakout on the toroid (at least that's my theory so far).
Probably some combination of breakout heating and air above it heating.

I think this has more to do with just the low BPS. My DRSSTCs does not like low BPS at all. It will give me racing sparks on the secondary and very unstable spark output. I am not quite sure why low BPS is a bigger problem than single shot. Maybe its some kind of timing/residual charge problem with the UD2.1 driver that is misbehaving.
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Offline AstRii

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Re: Small DRSSTC Questions
« Reply #16 on: December 27, 2022, 11:43:34 PM »
Isn't that just because at low BPS the bus caps reach their full voltage while at high BPS they might not charge quick enough? Even 1V drop on the input of the inverter can mean multiple kV difference at the output of a DR coil and at higher voltage it's easier to break out from toroid.
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Offline Mike

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Re: Small DRSSTC Questions
« Reply #17 on: January 09, 2023, 12:31:24 AM »
Quote
Isn't that just because at low BPS the bus caps reach their full voltage while at high BPS they might not charge quick enough?

I don't think so, if I quickly turn the coil output off and on again using the interrupter that should allow the bus cap to fully charge and result in the initial breakout from the toroid, but this isn't what I see. Also in the first video you can see that when I observed the breakout from the toroid to the strike ring I turned off the coil (by reducing the pulse width to zero) then increased the BPS and turned the pulse width back up. Initially there were still toroid breakouts, but these stopped after a couple of seconds. During this time I wasn't adjusting any parameters. If it was a voltage effect I would have expected that to have either persisted or at least vanished very quickly (i.e. within a few ms).

I am wondering about the effects of an externally heated electrode, not that I'd want to bother with that normally, but as a means of better understanding the effect. This could be a small nichrome breakout powered by a battery, or possibly even just a tea candle.

Unfortunately I've suffered another bridge failure while adjusting the tuning on the primary. The current limiting allows the coil to operate a long way out of tune initially and you can ride on the current limit while the streamer grows sufficiently to bring the coil back into tune. This places a lot of stress on the freewheeling diodes and results in rather long on times which my bridge wasn't really optimized for this so I've been suffering a number of failures.

Another little anecdote, the failures I used to suffer from pushing things too hard using the UD2.7 typically destroyed one half of the bridge, but left the other intact. With the freewheeling controller, the failures tend to be more complete and destroy the entire bridge. I'm also seeing more gate emitter shorts rather than just the collector emitter shorts from the UD2.7. I'm not sure at the moment if this is due to higher bridge temperatures, or something more fundamental to the way the freewheeling current limit works.




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Re: Small DRSSTC Questions
« Reply #17 on: January 09, 2023, 12:31:24 AM »

 


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[Dual Resonant Solid State Tesla coils (DRSSTC)]
vince1
January 27, 2023, 12:49:46 PM
post Re: Ramped SSTC - Power Supply Question + General Improvements
[Solid State Tesla Coils (SSTC)]
davekni
January 27, 2023, 06:07:49 AM
post Re: Phase lead problems on ud2.7c
[Dual Resonant Solid State Tesla coils (DRSSTC)]
davekni
January 27, 2023, 05:22:46 AM
post Re: Welding a MOT
[Transformer (Iron Core)]
davekni
January 27, 2023, 05:10:14 AM
post Re: First test of the SSTC
[Solid State Tesla Coils (SSTC)]
davekni
January 27, 2023, 05:05:40 AM
post Re: improving zvs driver
[General Chat]
davekni
January 27, 2023, 04:44:24 AM
post Phase lead problems on ud2.7c
[Dual Resonant Solid State Tesla coils (DRSSTC)]
vince1
January 27, 2023, 01:26:20 AM
post Re: improving zvs driver
[General Chat]
x-rayLamp
January 26, 2023, 08:13:24 PM
post Re: First test of the SSTC
[Solid State Tesla Coils (SSTC)]
LoOdaK
January 26, 2023, 12:02:14 PM
post Re: Welding a MOT
[Transformer (Iron Core)]
Alberto
January 26, 2023, 12:01:48 PM
post Re: Ramped SSTC - Power Supply Issues
[Solid State Tesla Coils (SSTC)]
ZakW
January 26, 2023, 05:35:32 AM
post Re: My completed 14-stage Cockroft-Walton voltage multiplier
[Voltage Multipliers]
MRMILSTAR
January 26, 2023, 04:55:24 AM
post Re: improving zvs driver
[General Chat]
davekni
January 26, 2023, 04:14:49 AM
post Re: My completed 14-stage Cockroft-Walton voltage multiplier
[Voltage Multipliers]
davekni
January 26, 2023, 03:57:19 AM
post Re: Welding a MOT
[Transformer (Iron Core)]
davekni
January 26, 2023, 03:42:01 AM
post Re: Welding a MOT
[Transformer (Iron Core)]
Da_Stier
January 25, 2023, 10:21:43 PM
post Welding a MOT
[Transformer (Iron Core)]
Alberto
January 25, 2023, 09:37:27 PM
post Re: My completed 14-stage Cockroft-Walton voltage multiplier
[Voltage Multipliers]
MRMILSTAR
January 25, 2023, 09:36:22 PM
post Re: improving zvs driver
[General Chat]
SteveN87
January 25, 2023, 08:35:49 PM
post improving zvs driver
[General Chat]
x-rayLamp
January 25, 2023, 04:32:37 PM
post Re: MidiStick V2.0: Next gen tesla coil interrupter
[Computers, Microcontrollers, Programmable Logic, Interfaces and Displays]
nzoomed
January 25, 2023, 08:27:01 AM
post Re: Ramped SSTC - Power Supply Issues
[Solid State Tesla Coils (SSTC)]
davekni
January 25, 2023, 04:08:42 AM
post Re: Ramped SSTC - Power Supply Issues
[Solid State Tesla Coils (SSTC)]
ZakW
January 24, 2023, 06:37:39 PM
post Re: Ramped SSTC - Power Supply Issues
[Solid State Tesla Coils (SSTC)]
davekni
January 24, 2023, 05:21:49 AM
post Re: 8 kW Induction Cooktop Teardown and Reverse engineering
[Electronic Circuits]
davekni
January 24, 2023, 04:41:01 AM
post Ramped SSTC - Power Supply Question + General Improvements
[Solid State Tesla Coils (SSTC)]
ZakW
January 23, 2023, 10:48:17 PM
post Re: 8 kW Induction Cooktop Teardown and Reverse engineering
[Electronic Circuits]
rikkitikkitavi
January 23, 2023, 10:23:54 PM
post Re: 160mm DRSSTC project
[Dual Resonant Solid State Tesla coils (DRSSTC)]
Mathieu thm
January 23, 2023, 07:21:10 PM
post Re: 160mm DRSSTC project
[Dual Resonant Solid State Tesla coils (DRSSTC)]
futurist
January 23, 2023, 06:21:07 PM
post Re: 8 kW Induction Cooktop Teardown and Reverse engineering
[Electronic Circuits]
Mads Barnkob
January 23, 2023, 01:23:41 PM
post Re: First test of the SSTC
[Solid State Tesla Coils (SSTC)]
davekni
January 22, 2023, 07:17:25 PM
post Re: First test of the SSTC
[Solid State Tesla Coils (SSTC)]
LoOdaK
January 22, 2023, 12:53:01 PM
post Re: First test of the SSTC
[Solid State Tesla Coils (SSTC)]
davekni
January 22, 2023, 06:21:40 AM
post Re: Creating arcs off my variac lol, popped my igbts
[Transformer (Iron Core)]
klugesmith
January 22, 2023, 04:45:46 AM
post Re: First test of the SSTC
[Solid State Tesla Coils (SSTC)]
LoOdaK
January 21, 2023, 11:47:55 PM
post [WTS] (free except shipping) 115V 3600RPM sync. motor
[Sell / Buy / Trade]
davekni
January 21, 2023, 08:50:05 PM
post Re: First test of the SSTC
[Solid State Tesla Coils (SSTC)]
davekni
January 21, 2023, 08:19:31 PM
post Re: First test of the SSTC
[Solid State Tesla Coils (SSTC)]
LoOdaK
January 21, 2023, 03:01:21 PM
post Re: First test of the SSTC
[Solid State Tesla Coils (SSTC)]
davekni
January 21, 2023, 05:44:15 AM
post Re: Creating arcs off my variac lol, popped my igbts
[Transformer (Iron Core)]
Avenger
January 21, 2023, 04:44:09 AM
post Re: First test of the SSTC
[Solid State Tesla Coils (SSTC)]
LoOdaK
January 20, 2023, 10:52:40 PM
post Re: QCW questions
[Dual Resonant Solid State Tesla coils (DRSSTC)]
davekni
January 20, 2023, 06:20:32 AM
post Re: QCW questions
[Dual Resonant Solid State Tesla coils (DRSSTC)]
Rafft
January 20, 2023, 06:03:20 AM
post Re: QCW questions
[Dual Resonant Solid State Tesla coils (DRSSTC)]
davekni
January 20, 2023, 04:49:50 AM
post Re: First test of the SSTC
[Solid State Tesla Coils (SSTC)]
davekni
January 20, 2023, 04:19:23 AM
post Re: First test of the SSTC
[Solid State Tesla Coils (SSTC)]
Rafft
January 20, 2023, 03:12:39 AM
post Re: MidiStick V2.0: Next gen tesla coil interrupter
[Computers, Microcontrollers, Programmable Logic, Interfaces and Displays]
TMaxElectronics
January 19, 2023, 11:39:37 PM
post Re: First test of the SSTC
[Solid State Tesla Coils (SSTC)]
LoOdaK
January 19, 2023, 10:54:51 PM
post Re: 160mm DRSSTC project
[Dual Resonant Solid State Tesla coils (DRSSTC)]
Mathieu thm
January 19, 2023, 09:19:19 PM
post Re: First test of the SSTC
[Solid State Tesla Coils (SSTC)]
Mads Barnkob
January 19, 2023, 08:33:18 PM
post Re: QCW questions
[Dual Resonant Solid State Tesla coils (DRSSTC)]
Rafft
January 19, 2023, 03:48:02 PM
post Re: First test of the SSTC
[Solid State Tesla Coils (SSTC)]
LoOdaK
January 19, 2023, 11:09:39 AM
post Re: QCW questions
[Dual Resonant Solid State Tesla coils (DRSSTC)]
davekni
January 19, 2023, 04:30:49 AM
post Re: 8 kW Induction Cooktop Teardown and Reverse engineering
[Electronic Circuits]
klugesmith
January 19, 2023, 03:10:56 AM
post Re: 8 kW Induction Cooktop Teardown and Reverse engineering
[Electronic Circuits]
Mads Barnkob
January 18, 2023, 08:23:57 PM
post Re: Creating arcs off my variac lol, popped my igbts
[Transformer (Iron Core)]
Mads Barnkob
January 18, 2023, 08:13:28 PM
post Re: 160mm DRSSTC project
[Dual Resonant Solid State Tesla coils (DRSSTC)]
dbach
January 18, 2023, 05:56:11 PM
post Creating arcs off my variac lol, popped my igbts
[Transformer (Iron Core)]
breezetix
January 18, 2023, 08:24:15 AM
post Re: QCW questions
[Dual Resonant Solid State Tesla coils (DRSSTC)]
Rafft
January 18, 2023, 06:40:30 AM
post Re: QCW questions
[Dual Resonant Solid State Tesla coils (DRSSTC)]
davekni
January 18, 2023, 06:29:45 AM
post Re: QCW questions
[Dual Resonant Solid State Tesla coils (DRSSTC)]
Rafft
January 18, 2023, 04:56:33 AM
post Re: QCW questions
[Dual Resonant Solid State Tesla coils (DRSSTC)]
davekni
January 18, 2023, 04:39:55 AM
post Re: 8 kW Induction Cooktop Teardown and Reverse engineering
[Electronic Circuits]
davekni
January 18, 2023, 04:27:49 AM
post Re: 160mm DRSSTC project
[Dual Resonant Solid State Tesla coils (DRSSTC)]
Mathieu thm
January 17, 2023, 11:16:00 PM
post Re: 8 kW Induction Cooktop Teardown and Reverse engineering
[Electronic Circuits]
rikkitikkitavi
January 17, 2023, 09:37:16 PM
post Re: 8 kW Induction Cooktop Teardown and Reverse engineering
[Electronic Circuits]
klugesmith
January 17, 2023, 05:38:24 PM
post Re: I need a review of my circuit. Polarities specifically
[Electronic Circuits]
RoamingD
January 17, 2023, 03:35:47 PM
post Re: 8 kW Induction Cooktop Teardown and Reverse engineering
[Electronic Circuits]
rikkitikkitavi
January 17, 2023, 12:43:26 PM
post Re: 8 kW Induction Cooktop Teardown and Reverse engineering
[Electronic Circuits]
klugesmith
January 17, 2023, 07:51:05 AM
post Re: QCW questions
[Dual Resonant Solid State Tesla coils (DRSSTC)]
Rafft
January 17, 2023, 07:02:37 AM
post Re: 8 kW Induction Cooktop Teardown and Reverse engineering
[Electronic Circuits]
Twospoons
January 17, 2023, 05:41:59 AM
post Re: QCW questions
[Dual Resonant Solid State Tesla coils (DRSSTC)]
davekni
January 17, 2023, 05:41:38 AM
post Re: QCW questions
[Dual Resonant Solid State Tesla coils (DRSSTC)]
Rafft
January 17, 2023, 05:06:24 AM
post Re: 8 kW Induction Cooktop Teardown and Reverse engineering
[Electronic Circuits]
davekni
January 17, 2023, 05:04:21 AM
post Re: 8 kW Induction Cooktop Teardown and Reverse engineering
[Electronic Circuits]
klugesmith
January 17, 2023, 04:41:26 AM

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