Author Topic: QCW questions  (Read 15571 times)

Offline Rafft

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Re: QCW questions
« Reply #140 on: January 06, 2023, 04:37:40 AM »
On my current setup, hi side lead length is already short, so id probably add a few, to have the additional turns on bead. Whats the reason though for adding a 1T series after the mentioned 3-4T?

Issue to solve: still a bit of overshoot(bridge output). Undershoot was solved with the R+D on discharge.

Im unsure what material I used on the hi side bead. IIRC these came from inside a printer. From paper feeder motor leads(?) .
« Last Edit: January 06, 2023, 04:45:13 AM by Rafft »
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Online davekni

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Re: QCW questions
« Reply #141 on: January 06, 2023, 05:26:50 AM »
Quote
On my current setup, hi side lead length is already short, so id probably add a few, to have the additional turns on bead.
Then I'd probably leave as is.  No reason to add lead length.

Quote
Whats the reason though for adding a 1T series after the mentioned 3-4T?
The 1T bead increases common-mode impedance at very high frequencies where capacitance may shunt the 3-4T.  As I said, this is the perfectionist version.  I probably didn't need either of the common-mode chokes, and especially not the extra bead.

Quote
Issue to solve: still a bit of overshoot(bridge output). Undershoot was solved with the R+D on discharge.
Common mode chokes on gate drive are not likely to fix output overshoot.  Is it bad enough to need fixing?  If so, it is likely related to one of the following:
1) Too little (or too much) phase lead.
2) Too little (or perhaps too much) dead time.
3) High parasitic inductance in H-Bridge construction.  Probably not this issue.  Image shows nice short IGBT leads.  Presuming ECB behind IGBTs has overlapped parallel planes as I've discussed elsewhere, that's about as good as is practical.

Quote
Im unsure what material I used on the hi side bead. IIRC these came from inside a printer. From paper feeder motor leads(?) .
Most likely an MnZn material.  Those are more common.  If you have more of these cores, you can test by holding one (with an insulating handle) in any form of spark (from spark coil or flyback or etc.).  I you can make arc jump to one corner of bead and exit other corner, it is MnZn.  If arc goes around bead (along bead surface), then it is NiZn.
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Offline Rafft

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Re: QCW questions
« Reply #142 on: January 06, 2023, 05:47:07 AM »
My most likely answer to what might be my problem is on your 3rd qoute.

Im using a gapped EE core (for L= around 14uH) and 33R, from the stock UD phase lead(variable L, 51R). And BACK to using stock UD comparator circuit.

Things ive noticed:
*I can start my coil even w/o the initial 'wick'
*triple-transition is absent no matter how I tweak inductor value

I think too little phase lead I presume(?)

Regarding layout, its 2layer board. Low inductance layout as per your suggestion before.

Really cant seem to get rid of that distortion (Ipim) 1v=100Apk. Have also upgraded my bulk cap from 6600uF to 13200uF. My boost also to a max 327Vdc. Scope shots shown with only ~290vdc bus
« Last Edit: January 06, 2023, 06:04:13 AM by Rafft »
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Re: QCW questions
« Reply #143 on: January 06, 2023, 06:00:09 AM »
Quote
*triple-transition is absent no matter how I tweak inductor value
LoneOceans has a good DRSSTC design project page showing triple transitions and phase lead adjustment:
https://www.loneoceans.com/labs/drsstc3/
He initially has excess dead time, making large long triple transitions.  After reducing dead time, triple transition shows up as just a small bump in H-bridge output, not full transitions.  As he says, this is ideal dead time.  If dead time is too short, there will be no hint of triple transition at any phase lead adjustment.  Or, if dead time is sufficient, then phase lead isn't being adjusted across the ideal point.  Either all too little or all too much phase lead (less likely).
David Knierim

Offline Rafft

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Re: QCW questions
« Reply #144 on: January 06, 2023, 06:13:16 AM »
Yes Ive been reading that exact artice as well

But what is the reason why lowering the resistor value from 51R to 33R made the coil more 'sensitive' and easier to start(even w/o wick)? Even with 45Vdc on bus, it can start

Going back to using 51R, it has erratic operation(needing wick) but even at 150vdc bus, it still has erratic operation. Turning OFF my boost ckt(discharging the bulk caps) and it will work *just fine* until bus voltage gets too low..
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Re: QCW questions
« Reply #145 on: January 06, 2023, 08:36:59 PM »
David

I did the 3T+1T bead for the hi-sw. All gate res are equal(hi lo)

It must have done something because now coil again needs 'wick' to operate.

Done some adjustments as well on the phase lead. Removed secondary, using only primary & mmc. This was done in regular DR mode. No ramp supply. Test with 45vdc bus. DR interruptor. Yellow(fullbr output) blue(Iprim)

Adjustments where done to get the cleanest Iprim waveform
While also noting the bridge output 'peaks'.

Here are the results. W/c of the 2 shots is better?

Edit
Added 3 more images. Iprim cleaned up a bit  :)
« Last Edit: January 07, 2023, 03:36:39 AM by Rafft »
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Re: QCW questions
« Reply #146 on: January 07, 2023, 03:59:02 AM »
Quote
It must have done something because now coil again needs 'wick' to operate.
UD2.7 startup at low Vbus is inherently marginal.  Depends on first half-cycle generating enough feedback to trigger second half-cycle.  Required feedback voltage depends on diode Vf of the back-to-back clamp diodes, which is temperature dependent.  You can improve startup by adding resistors across the two IGBTs that are off during the first half cycle of each burst.  That way MMC is charged to opposite state, making larger first-half-cycle signal.

Quote
Here are the results. W/c of the 2 shots is better?
Hard to say.  Both are likely OK.  Duty cycle looks close to 50%, but there must be enough difference to cause the significant difference between rising and falling edges of H-Bridge output.  Would be a bit easier to tell looking at each H-Bridge output separately rather than the difference between the two.  No way in these images to determine if the two outputs contribute equally to shape of transitions.  In an ideal world, H-Bridge outputs are identical (except for 180 degree phase shift) and rising edges look exactly like inverted falling edges.  Real world examples can come close, but often don't.
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Re: QCW questions
« Reply #147 on: January 07, 2023, 04:18:20 AM »
1st photo was using 56R(LR on input) for phase lead & triple transition present. 2nd photo was using 33R & just a hint of the triple transition. Both adjust to have minimum spikes.

I do recall I had a trimmer to adjust duty ratio for MAX913. Will go check on that

Thanks

Edit
Here are scope shots of Vce. 45vbus.DR mode.no secondary
Phase Lead adjusted to have minimum spike(fullbr output)

1 low
2 low
2 high
1 high
Output from comparator. Max913 pin#7(out) 50% duty. Inv_out is on pin#8(edit-sorry for that)
« Last Edit: January 16, 2023, 10:00:36 PM by Rafft »
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Re: QCW questions
« Reply #148 on: January 08, 2023, 06:13:32 AM »
Quote
Edit
Here are scope shots of Vce. 45vbus.DR mode.no secondary
Phase Lead adjusted to have minimum spike(fullbr output)

1 low
2 low
The two low Vce captures are all that is needed.  Avoids scope ground capacitance loading H-Bridge output.  Falling edge of low Vce should be identical to rising edge of high Vce.  Differences in your captures prove that scope ground loading is affecting measurements at least some.

There is still a significant difference between rising and falling edges.  Duty cycle seems close to 50%.  Slightly above 50% on Max913 pin#7(inv out) capture you show.  Not sure that is enough to explain differences in H-Bridge outputs.  I wonder if your four IGBTs aren't all the same inside.  Perhaps some have more gate capacitance or have slower turn-off times.  Looks like more dead time on 1 rising edges and a bit more on 2 falling edges, with less on 1 falling and 2 rising.  (I think you said that all gate resistors are identical, as is recommended.)

These all look good enough even though not quite symmetric.  I'd perhaps aim for slightly more phase lead to compensate for IGBTs slowing down when hot, even though spikes will be a bit higher initially.
David Knierim

Offline Rafft

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Re: QCW questions
« Reply #149 on: January 08, 2023, 06:20:22 AM »
Thanks for checking

Yes all IGBT are of same batch(on order). Yes all gate res to be the same.

Btw how should lo Vce look like? Almost/no spike?

Should I just remove 3T +1T? And just make it 1T?

'Aim for more phase lead' ,is it literally like more R or more L value at feedback input?

« Last Edit: January 08, 2023, 06:26:30 AM by Rafft »
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Re: QCW questions
« Reply #150 on: January 08, 2023, 06:49:14 AM »
Quote
es all IGBT are of same batch(on order).
I was just wondering.  If the batch are counterfeit, perhaps they aren't all identical inside even if from same "batch".  I'm just struggling to explain why there's differences between the two H-Bridge outputs.  Differences between rising and falling could be the slight duty cycle deviation from 50%, but even that seems questionable.  Or, perhaps there is enough difference in GDT + leads leakage inductance between the four outputs to make a difference.

Quote
Btw how should lo Vce look like? Almost/no spike?
Ideally, as you adjust phase lead, there will be a point where there is a small triple-transition.  As phase lead is adjusted slightly higher, that triple transition will fade to just a bump.  There is likely to be a small spike after each edge as opposite IGBT diode turns on.  No large spikes.

Quote
Should I just remove 3T +1T? And just make it 1T?
If 3T is adding significantly to GDT lead length, then it might be an issue.  However, if leads are twisted pair through 3T ferrite, length isn't likely to add enough inductance to be significant.

Quote
'Aim for more phase lead' ,is it literally like more R or more L value at feedback input?
Phase lead is determined by L/R.  More lead is either more L or less R.
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Offline Rafft

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Re: QCW questions
« Reply #151 on: January 08, 2023, 06:58:59 AM »
Thanks again David

My gdt leads are as short as can be possible.

I was thinking maybe add more gate res... Because D+R certainly fixxed the undershoot(bridge output)

Regarding phase lead, I will user a higher inductor value and keep the 33R(or I might try 22R if my junkparts have)

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Re: QCW questions
« Reply #152 on: January 08, 2023, 07:58:29 AM »
David

/>
1 lo Vce
2 lo Vce (why so high spike?)
3 bridge output(yellow) and blue(Iprim)

Is this ok now? Or should I add more phase lead? Iprim looks clean enough
« Last Edit: January 08, 2023, 08:08:11 AM by Rafft »
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Re: QCW questions
« Reply #153 on: January 08, 2023, 07:28:44 PM »
Quote
2 lo Vce (why so high spike?)
Might be just IGBT package inductance.  Even with perfect H-bridge construction, TO247 packages have about 13nH lead inductance.  Internal IGBT anti-parallel diode forward recovery time may be contributing.  This ~30V spike will likely grow some with higher current.  Even if it grows to 100V, you have sufficient margin between Vbus and 600V IGBT rating.

Quote
Is this ok now? Or should I add more phase lead? Iprim looks clean enough
Yes, I think it is good enough.  No need to obsess with elusive perfection.

Video nicely shows the normal Vbus ring as interrupter turns off.  Also shows how residual H-bridge output voltages changes, which is one factor in why startup sometimes works and sometimes doesn't at low Vbus voltage.
David Knierim

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Re: QCW questions
« Reply #154 on: January 11, 2023, 04:58:18 PM »
Few component tweaks & phase lead re-adjust did give me a small performance increase. 12mF bus cap. 150Apk@300vdc bus. That bigass topload really makes the spark look tiny .... And those tiny twigs ruin the sword. Wonder if high k has something to do with it

Module next to coil (& inverter) is my boost-buck.

Thanks again David  :)

 


 
« Last Edit: January 11, 2023, 05:30:24 PM by Rafft »
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Re: QCW questions
« Reply #155 on: January 12, 2023, 03:13:07 AM »
Great performance!  Always nice to see success.

Quote
Wonder if high k has something to do with it
I don't think so.  I think most QCW coils have high coupling, certainly much higher than conventional DRSSTCs.  In general, I think higher is better for QCW.  However, my only real QCW experience is with my failed low-frequency experiment.  I believe its issues were due to 100kHz (and eventually due to insulation failure), not due to its 0.9 coupling factor.

Edit:  Bit more thought leads me to the possibility that lower coupling could have one advantage.  More energy stored in primary could smooth over imperfections in buck converter ramp smoothness.  However, lower coupling will make energy transfer from primary to secondary change more as arc grows and changes secondary frequency.
« Last Edit: January 12, 2023, 03:22:30 AM by davekni »
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Re: QCW questions
« Reply #156 on: January 12, 2023, 09:59:42 AM »
Hi David

Sorry to be back again.. But.. Im here to learn  ;. More
Ive read on others posts, ZVS tuning..so I will try. Gifted with a proper scope & I should need to use it properly!

vbus 45vdc
Yellow(Vce lo sw)
Blue(Vge lo sw)

This is a problem, right?  Thats why the spike. Looks like igbt needs to switch off earlier? Or is this something else? Gate drive looks non-symetrical(?) Or I should probably accept the fact im using counterfk igbts  ;D

Last image; higher rep rate drsstc int
Yellow(Vce) blue(Vge) cyan(Iprim)

Last last 2 images. I removed the big bead 3T. And removed the extra wires going to HI sw.but installed a teeny tiny bead instead. 1T. Your right, almost no difference w beads. 2nd photo is w bridge output and Iprim

Regarding gate resistors, with UD2.7(output) , is 1/4watt enough?

EDIT:
Quote
Bit more thought leads me to the possibility that lower coupling could have one advantage.  More energy stored in primary could smooth over imperfections in buck converter ramp smoothness.  However, lower coupling will make energy transfer from primary to secondary change more as arc grows and changes secondary frequency.

by how much lower? like .1 or .2? last time I checked mine was around .6. lower coupling WILL increase Iprim(maybe >200Apk) if trying to get same output. everything is in a balance.

everything from coupling k/lower-upper poles/size of torroid/ratio (of primary L and MMC C, big or small values). regarding the buck converter ramp smoothness, I havent touched anything on the resonator part, just the gate res/L in hi side phase lead/phase lead adjustment. thats why my previous was I could get it to ramp-up from zero, to the recent ramp w 'blip' on the start.

Ive made mine to achieve long sparks with minimum primary current I could give it. my OCD though is setup for 200Apk

btw hows your HF(?) QCW coming along?
« Last Edit: January 12, 2023, 02:07:35 PM by Rafft »
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Offline Rafft

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Re: QCW questions
« Reply #157 on: January 12, 2023, 06:36:35 PM »
I will just continue here  :)

Now I understood more

**Initial scoping
**Replaced gate resistor values(lower R), faster turn-on perhaps(?)
**Replaced phaselead resistor(lesser phaselead)worst ringing Vce(yellow) Vge(cyan) Iprim(magenta). Also noting the earlier ON of Vge
**Replaced again higher gate resistor. Adding more phaselead. Now Vge can be seen turning on just in time before Vce switches off
**Iprim(magenta) bridge output(yellow)

I hope Im correct on what I see on scope


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Re: QCW questions
« Reply #158 on: January 13, 2023, 05:36:32 AM »
Nice detail in your scope captures!  I appreciate the zoomed-in shots being added (100ns/div), and the ones with current centered and scaled up to make zero-crossing points easier to see.  Takes me less time to analyze your scope images now.

Quote
This is a problem, right?  Thats why the spike. Looks like igbt needs to switch off earlier? Or is this something else? Gate drive looks non-symetrical(?) Or I should probably accept the fact im using counterfk igbts  ;D
Actually, I think these initial scope traces look quite good.  The positive spike on Vce is due to some combination of H-bridge wiring inductance (including or perhaps mostly IGBT package lead inductance) and internal IGBT antiparallel diode forward recovery time.  (Counterfeit IGBT parts may have slow diodes.)  Low-side IGBT is turning off before current reaches zero, exactly as it should.  Remaining current causes rising edge of Vce.  When Vce reaches Vbus (45V), diode of high-side IGBT clamps it to Vbus.  Delay in diode turn-on (forward recovery time) and/or inductance allows Vce to spike above Vbus for ~50ns.  I don't think that will cause any problems.  Following the spike, notice that there is another 60-70ns plateau then a small drop in Vce.  This is high-side IGBT diode forward drop changing to IGBT on-state Vce as current passes through zero and changes polarity.  This brief plateau and small drop demonstrates the desired ZVS turn-on condition.

Quote
Regarding gate resistors, with UD2.7(output) , is 1/4watt enough?
Probably not enough power.  However, many small details can affect power.  Not easy to calculate with any simple formula.  One way to estimate is to measure UD2.7 driver FET power (current times voltage) consumption (or perhaps total +24V power if hard to separate).  Worst-case half of that power will end up in gate resistors, so 1/8th per resistor.  More likely less than that, perhaps 1/16th of UD2.7 output FET power per gate resistor.

Quote
by how much lower? like .1 or .2? last time I checked mine was around .6. lower coupling WILL increase Iprim(maybe >200Apk) if trying to get same output. everything is in a balance.
Wow, is your coil coupling really 0.6?  That high is difficult to achieve without secondary-to-primary arcing.  Other QCW coils I've seen on the forum range from 0.35 to 0.55.  0.55 coil required ferrite core to get that high.  I wouldn't go below 0.35 minimum.

Quote
btw hows your HF(?) QCW coming along?
Slowly as always.  Some work last October and November, then a break for Christmas etc.  Hard to host family when my dining room table is filled with project material.  Hope to have it operational by summer.

Quote
**Replaced gate resistor values(lower R), faster turn-on perhaps(?)
Yes, faster turn-on, which reduces dead-time given same turn-off time (which isn't quite accurate due to higher loading on UD2.7 and GDT).  Rising edge still has sufficient phase lead for clean transition.  Falling edge doesn't complete Vce transition before low-side IGBT turns on.  That causes the noise on falling edges.

Quote
**Replaced phaselead resistor(lesser phaselead)worst ringing Vce(yellow) Vge(cyan) Iprim(magenta). Also noting the earlier ON of Vge
Yes, made falling edge even worse.  Vce barely starts to fall before low-side IGBT turns on.  Current is so close to 0 by the time high-side IGBT turns off that it can't effectively cause low-side Vce to drop (high-side Vce to increase).

Quote
**Replaced again higher gate resistor. Adding more phaselead. Now Vge can be seen turning on just in time before Vce switches off
This is best adjustment yet.  At least best under these conditions.  Conditions in your first post have a bit more spike due to a bit more phase lead, so current is a bit farther before zero at turn-off.  That margin might be helpful if IGBTs slow down significantly as they get hot (normal behavior for IGBTs and most silicon devices).  On the other hand, higher bus voltage reduces IGBT capacitance.  Lower capacitance might add just enough margin for slowdown due to heat.  Difficult to know exactly where perfection is.  Either this state or the one of your first post of this pair is probably just fine.  Seems that you are learning a lot with this drive for perfection.  That part is good.  Don't get obsessed with perfection as I too-often do.
David Knierim

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Re: QCW questions
« Reply #159 on: January 16, 2023, 01:43:48 PM »
David

I know this is probably fine by now but.. When phase lead tuning, whats 'best' to watch out for? Get minimum 'spike' (yellow,Vce) or the ringing(of Vce) when Vge(cyan) turns ON?

Or just disregard that ringing of Vce(Vge turn-on) b/c its insignificant already(?)

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Re: QCW questions
« Reply #159 on: January 16, 2023, 01:43:48 PM »

 


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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
post Re: QCW questions
[Dual Resonant Solid State Tesla coils (DRSSTC)]
davekni
January 17, 2023, 04:35:36 AM
post Re: 8 kW Induction Cooktop Teardown and Reverse engineering
[Electronic Circuits]
Avenger
January 17, 2023, 04:24:24 AM
post Re: QCW questions
[Dual Resonant Solid State Tesla coils (DRSSTC)]
Rafft
January 17, 2023, 04:13:11 AM

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