Author Topic: Help for people buying the "12-48 Volt 1800/2500 Watt ZVS induction Heater"  (Read 61239 times)

Offline rikkitikkitavi

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How about buffering the server with a beefy set of caps that takes the brunt of the ripple? In a post LC filter style.

You would probably need inductors(L) between the supply and these cap banks (C) or otherwise it might either be difficult to start the supply due to the charging current trips overcurrent protection, or the reduced ESR might cause instability problems due to regulation loop going haywire.


A man can not have too many variacs

Offline hightemp1

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A 10% voltage boost should give a 21% power boost.  Voltage is 1.1x.  Current will follow, so be 1.1x.  1.1 * 1.1 = 1.21x (power is current * voltage).

If you stay at 40kHz the existing inductors might suffice.  They appear to work for the 3kW units sold on EBay, which look like this 2.5kW unit with large fans added.  If you add caps to reduce frequency, you will almost certainly need larger inductors.

A bit of explanation on the inductors - please ignore if it doesn't make sense:  When current increases, iron-core inductors saturate, so inductance drops.  At high current, inductance can drop to a tiny fraction of what you measure with a meter.  The low inductance causes high current ripple.  High ripple current can cause two problems.  First, it may cause your DC supply to shut down due to over-current spikes.  Even if the supply doesn't shut down, high ripple current is heating the supply's output capacitors, which may lead to eventual failure of the supply.  (The supply's intended server use doesn't draw significant ripple current from the supply.)  The other issue which may show up first is added FET current.  The high ripple current comes from the supply and is conducted through the FETs.  Even with the better FETs I suggested, if ripple current gets high enough, the FETs forward voltage drop will be too high to keep the opposite FETs off.  The result will be fried FETs.

Unfortunately, there is no simple way to design inductors.  Measuring with your meter gives inductance at low (almost zero) current.  Saturation can make the inductance drop by an order of magnitude or more at high current.  High-current inductors are usually custom-made for specific applications.  I don't know of any good source for pre-made 50A inductors.

Thats' good stuff!!  Pete, do you know if your PS's voltage can be tweeked - seems like 10% is a safe overclock, if you have the POTs? 

David, wondering if you watched the 3kw heater build on page 17 by Schematix-"the dreamer" ?  He has a riduculously huge work coil for a 3kw heater and more caps than we do.  When he cranks up the volts to 50 he experiences exactly what you are referencing I think (at 15 minutes, 15 seconds into the video  - ferrite coils were getting very hot.  Most importantly though is his solution for expensive bigger ferrite coils (doubling or paralleling two smaller sized coils).  Seams like the way to go for bigger coils, no? His design is a little different but the ganged coils did the trick of both cooling em down and smoothing out wave forms on his scope.   

Just dawned on me that longer and wider work coils decreases inductance, not the other way (doh!) I keep mixing em up - but bigger is great for getting closer to target frequency.   

So far here are the proposed mods:  Crank up volts 10%, doubling up fan-cooled caps to underside of board, ganging pairs of ferrite inductors to increase inductance, plus one longer and one bigger work coil.  Now, at last, 500 more watts will be available to work coils with more conducive frequencies for melting metal, and the full power of the PS will be utilized! Thank you Peter & David!!!!

Addendum: Adding two more mosfets is still on the table but a little more complicated, at least for me.  I get how replacing all existing FETs with better quality ones allows for more stability (good for long metal melts) and marginaly more efficient system, but not sure what adding two more mosfets does?

Another dumb question.  Pete, I noticed you have a DC switch to power on ZVS after PS is powered on (now china copied you and includes them).  Looks like you also now have a SSR relay.  Wondering if I could ommit buying the DC switch and just use the relay to power on ZVS?  I like the relay idea as a future temperature controller, but wondering if it can also replace the DC switch.
https://www.ebay.com/itm/173467987699?chn=ps&mkevt=1&mkcid=28&var=472165317799

« Last Edit: March 06, 2021, 04:49:59 AM by hightemp1 »

Online davekni

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Yes, I saw the video.  BTW, the inductor cores are powdered metal (iron alloy), not ferrite.  Using two identical cores with the same number of winding turns will double inductance, but leave current rating the same.  Using two cores with 71% of the turns (sqrt(0.5)) will give the same inductance as original with 1.41x current capability (sqrt(2)).  90% of the original turn count might be about right for your plans - 11% more current capability and 1.62x original inductance.  He is running 38kHz per the scope capture.  If you plan to lower frequency below ~30kHz, then you may need yet more inductance.

For a given work coil turn count, wider increases inductance, longer decreases inductance.  If you add turns to make it longer, then longer increases inductance due to the increased turn count.

Adding two more FETs is similar to replacing the existing ones, but requires additional 5W 470ohm resistors and diodes, and still doesn't switch as fast (more losses).  The replacements I suggested are closer to adding 4 more FETs.

Some SSRs can't handle inductive loads well.  You may need to add a diode across the ZVS DC power input to prevent voltage spiking at turn-off.  Of course, that diode needs to be in the direction to not conduct normally (cathode to + supply, anode to - supply of ZVS board).
David Knierim

Offline rikkitikkitavi

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Tip: You can rip out the filter inductor of old ATX power supplies for the 5V and 12V part, and possibly the PFC correction circuit. They are mostly powdered iron or material with similar properties (low AC ripple but high DC current)  and sized maybe somewhat in the right direction (1,5 inch and larger) so parallelling cores to allow for higher current might work if you have some large ones and perhaps not the largest IH.

Or if you are lucky and have some humungously large ferrite cores you can always gap them with paper to get the right inductance but they still saturate HARD at much lower flux densities than powdererd iron cores so you have got to know your core, and hard saturation would at best trip overcurrent in your power supply, at worst fry the lot.

Using a relay for on/off PWM regulation of the IH might pose some problems, as they have to be rated for a huge current. But with a low PWM frequency (after all time scale is in the seconds/minutes) wear and tear might be keept reasonable but still I expect relays to fail frequently.
« Last Edit: March 06, 2021, 08:53:05 PM by rikkitikkitavi »
A man can not have too many variacs

Offline hightemp1

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Yes, I saw the video.  BTW, the inductor cores are powdered metal (iron alloy), not ferrite.  Using two identical cores with the same number of winding turns will double inductance, but leave current rating the same.  Using two cores with 71% of the turns (sqrt(0.5)) will give the same inductance as original with 1.41x current capability (sqrt(2)).  90% of the original turn count might be about right for your plans - 11% more current capability and 1.62x original inductance.  He is running 38kHz per the scope capture.  If you plan to lower frequency below ~30kHz, then you may need yet more inductance.

For a given work coil turn count, wider increases inductance, longer decreases inductance.  If you add turns to make it longer, then longer increases inductance due to the increased turn count.

Adding two more FETs is similar to replacing the existing ones, but requires additional 5W 470ohm resistors and diodes, and still doesn't switch as fast (more losses).  The replacements I suggested are closer to adding 4 more FETs.

Some SSRs can't handle inductive loads well.  You may need to add a diode across the ZVS DC power input to prevent voltage spiking at turn-off.  Of course, that diode needs to be in the direction to not conduct normally (cathode to + supply, anode to - supply of ZVS board).
  Most excellent sirs - thanks again!

Drawing close to 60 amps could be an issue especially with longer runtimes so modding larger traces may be advised.  Going by Schematix's video the traces that need to be enlarged are the ferrite inductors, the caps and the middle mosfet pins to each cap.  Seems like the wire gauge used in Schematix video was overkill if fan cooling is used as well.  Assumption - board is rated for 52 amps @ 48 volts, if fan and water cooled.   Plan is to add 500W to work-load by tweeking/increasing POT's power supply by 5 volts, then a 5 amp boast will naturally follow with a ZVS circuit.  Wondering if 16 gauge stranded copper wire will be sufficient to handle extra 5 amps/volts and extra 500 Watts of power?? Many of the traces appear to be hidden either under the large caps or invisibly sandwiched between top/bottom of board?  Still, all components have through-hole pins to back of board so it should be a simple matter to build up some solder on bottom of board to the caps, inductors and center pin of each mosfet, then solder a connectiing wire to all those pins, no?  While expanding traces, this may be a good time to reinforce any other suspect joints, like my previously mentioned power diode's lack of solder, or maybe just lightly beefing em all up as a matter of course. Also, since the capacitor doubling plan is to use existing cap through holes, consideration should be given to expanding holes or seeing if they both will fit in existing holes. As Dave explains in next posts, enlarging circuit board holes is a bad idea.

Another thought just occured to me - the two planned larger crucibles may naturally draw more amps @ 48 volts.  Possibly, one of the crucibles would draw 10 more amps by itself so increasing PS voltage would be unnecessary, or at least not by 10%.  If larger crucible/coil combos naturally draw more amps then larger traces become even more important, I would think, since in this case the 500W increase could come from an amperage only boast of 10 amps - volts remain untouched at 48. So maybe a thicker 14 gauge wire added to traces would be better here? 

Lastly, wondering what effect changing the work coil diamenter from quarter inch to 3/8 inch would have on the power level going to the work-load?  Or put another way, if you have a 1/4" and a 3/8" coil basically the same diameter, length, coil spacing, etc. is the 3/8" one more efficient and if so, by how much?

« Last Edit: March 13, 2021, 04:56:47 PM by hightemp1 »

Online davekni

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The largest current is from caps to work coil.  The other paths (to FET drain pins and to inductors) conduct less current, although still significant.
Skin depth for copper at 30kHz is 0.38mm.  Copper foil will be more effective than large-diameter wire.

If modifying an existing board, don't try to enlarge holes.  Holes are plated with copper inside.  Enlarging them will break the copper connection between top and bottom layers.  For adding caps, solder to the lead stubs of the existing caps.  Not super rigid mechanically, but will work fine electrically.

Larger work-coil tubing diameter should increase efficiency a bit.  So will reducing space between the work coil and crucible, although that makes insulation thinner so increase crucible heat loss.

Yes, hitting exactly 3000 watts will be tricky.  Any slight change in coil geometry or crucible placement or even crucible temperature will change the power draw a bit.
David Knierim

Offline hightemp1

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The largest current is from caps to work coil.  The other paths (to FET drain pins and to inductors) conduct less current, although still significant.
Skin depth for copper at 30kHz is 0.38mm.  Copper foil will be more effective than large-diameter wire.

If modifying an existing board, don't try to enlarge holes.  Holes are plated with copper inside.  Enlarging them will break the copper connection between top and bottom layers.  For adding caps, solder to the lead stubs of the existing caps.  Not super rigid mechanically, but will work fine electrically.

Larger work-coil tubing diameter should increase efficiency a bit.  So will reducing space between the work coil and crucible, although that makes insulation thinner so increase crucible heat loss.

Yes, hitting exactly 3000 watts will be tricky.  Any slight change in coil geometry or crucible placement or even crucible temperature will change the power draw a bit.

Wow, great info on thru holes, may also explain why I've had problems getting solder to stick on some hosed circuit boards I have repaired.  To solve rigidty issue I noticed the short bottom stand-offs have threads for accepting screws so I will find out the thread size and buy half a dozen long screws, then maybe attach to 1/8" plywood or acrylic sheet cut to same size as circuit board. Rigid connection between new plywood board and existing circuit board will not only protect caps but will also give a solid foundation for mounting fans to cool them.
Since going to 3/8 coil only gives minimal power increase, I will use up my large roll of 1/4" before moving onto 3/8".  In keeping with a minimalist "use what you got" mentality, rather than using copper foil, thinking about pounding 14 gauge wire flatter, annealing, repeat, etc., then drilling very small holes in DIY "foil" to attach to stubs and new caps, inductors, and existing mosfets.

Update: would this 63amp 125volt DC circuit breaker make an OK on/off DC switch?
https://www.ebay.com/itm/1P-63A-DC-125V-Circuit-breaker-MCB-C-curve/324176560751?hash=item4b7a6dc26f:g:qmMAAOSwLrleyr5V
« Last Edit: March 12, 2021, 10:26:29 AM by hightemp1 »

Offline petespaco

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I have been using a similar breaker as an on-off switch for my 2500 watt system for a few years now, and it works okay so far. However, I don't think I'd depend on them for overcurrent protection.  I have almost never turned that breaker OFF unless the system is down to its idle current state.   If you look at some of the kits or "combo's" that several sellers of ZVS heaters offer, you will see that they usually do include one of these for that exact purpose.

You can spend a lot of time trying to figure out  how those breakers really work for DC arc quenching.  Then, when you think you know enough, you still have to consider how much "Chinese de-rating" you need to put into your calculations.   At less than USD$3.00, what do you really think is going to be inside the shell?
After all, they can "fake" just about anything, and usually do.

Pete Stanaitis
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Online davekni

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I concur with Pete on the breaker use.  Probably fine as an on-off switch with some limited life.  I bought a similar cheap 250V DC breaker.  It had no internal magnet to force the arc into any quenching chamber.  It did not quench an arc, at least not in the couple seconds I allowed it to continue arcing.  I expect 50V will be less of a problem.
David Knierim

Offline hightemp1

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The largest current is from caps to work coil.  The other paths (to FET drain pins and to inductors) conduct less current, although still significant.
Skin depth for copper at 30kHz is 0.38mm.  Copper foil will be more effective than large-diameter wire.

Well, it is not exactly copper foil but I think thickness matches the capacitor's protruding stubs nicely.  Stubs are protruding about 1/20" of an inch and "foil" is also 1/20" of an inch thick.  Took me half hour of hammering, annealing, and straighting. All you blacksmiths could have done it in a couple of minutes.  Used regular construction 8 gauge soft wire, annealed it once - 8 gauge is border line as to even having to anneal at all to get to .05" or 1.25mm.  Will mark holes to drill in copper by pierceing stubs to a piece of copy paper -holes wil be large enough to accodomate extra caps.  Still need to hammer another similar cap strip, six shorter cap to mosfet strips(12 gauge), and 2 cap to inductors to coil post strips(8 gauge).  There are no traces in back so hopefully I will not melt circuit board when filling holes with 60/40 solder? -the circuit board's traces must be hidden under the caps on top side of board.  This trace MOD should now allow the unit's traces to easily hande 3000 Watts and 60 amps, up from china's stock 2,5KW.  Thank you David for the "modified foil" tip - flatter traces will be much neater than wire, and solder joints should be significantly studier than they would be with wire. ;D

Update: There are six mosfets and currectly 12 caps, possibly 2 series of 6 in parallel -no clue really?  In the Schematix video when he enlarges traces, he attaches the middle pin of each mosfet to the nearset cap.  I assume that I can do the same with all six of my mosfets?

In hindsight using 8 gauge wire seams like over-kill for just trying to get an extra 10 amps.  Can one have traces that are too large, or put another way do larger traces take power away from the work load?  For all I know 14 gauge is more than adequate.

UPDATE: AliExpress just came out with a circuit board only:
https://www.aliexpress.com/item/4000736471927.html?
« Last Edit: March 30, 2021, 07:59:20 AM by hightemp1 »

Online davekni

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No downside to added copper here, other than the work to add it.  The circuit board should handle soldering temperature fine as long as the board isn't under simultaneous mechanical stress.
David Knierim

Offline hightemp1

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No downside to added copper here, other than the work to add it.  The circuit board should handle soldering temperature fine as long as the board isn't under simultaneous mechanical stress.

Like Pete says china over specs and underpowers everything so it is comforting to know that pumping up traces should do no harm - thanks again. :)

Another question for you Pete - I know you have stated that the maximum sustained amperage you allow on your 2.5kw system is 50 amps.  So of course I am curious with these proposed MODs if you would feel confortable pushing your rig to 3kw? Please Dave or anyone else feel free to comment as well. Dave, I know you are not fond of the existing FETs(IRPF260N) specs but for 3kw(50volts @ 60 amps or 55v@55a maybe they are OK?

« Last Edit: April 09, 2021, 09:29:55 AM by hightemp1 »

Offline petespaco

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Maybe my self-imposed current limit of 50 amps at 48 volts is a bit arbitrary, but it's all too easy to stick something a bit too far into the work coil and see a short current surge well above that.   So---- I wouldn't be comfortable with a 60 amp limit.
Recently I have been making some "flattened" solenoid coils in an attempt  (not successful yet) to get small pieces of tool steel well beyond the curie point for forging.  During one test, I stuck a larger piece of bar into the coil and got a huge current surge that shorted the 60 amp DC to DC SSR that was in series with the load.  The Mosfets on the  pcboard didn't blow however.
  I guess you get to decide.

Pete Stanaitis
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Online davekni

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IRPF260N will work fine when cool.  As they heat up, on-state-resistance goes up and gate threshold voltage goes down (as with all FETs).  At high current and high temperature, the on-state FET can't pull it's drain voltage low enough to keep the opposite FET off.  When current is high and temperature reaches some threshold, the off-state FETs conduct enough current to generate more heat and yet higher temperature.  Result is thermal runaway.  (Better FETs could handle more current and higher temperature before reaching a runaway condition.)

In other words, it will work fine with aggressive cooling.  If FETs get too warm, thermal runaway and fried FETs will result.  If the FETs fry, then you have a good excuse to replace them with better ones.
David Knierim

Offline hightemp1

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Thanks guys!  Certainly won't be pushing FETs anytime soon, but future target will be 2.75kW (53volts @52 amps) for now.
Here is mofset datasheet for stock IRPF260N -makes no sense to me but posting for those who it does make sense:
https://www.vishay.com/docs/91215/91215.pdf

And here is one possible suggested mosfet upgrade #FDA70N20:
https://www.mouser.ie/datasheet/2/308/FDA70N20-D-1806350.pdf

If I do blow em up and upgrade to the above mosfets, then I am wondering if any of the mosfet's matching two resistor(s) values or two diode(s)specs also changed with changed mosfets? Or put another way, can above mosfets simply be swapped out without changing any other components?

Or alternatively, as mentioned in previous post, a cheaper mosfet upgrade would be to add two identical mosfets to the existing six mosfets, 8 total.  If two new mosfets are added do you foresee any problems in wiring them off the current board and on to my proposed plywood or plastic board that would be housing/supporting cooling fans underneath the existing circuit board?  Or more to the point, would Dave or someone please be so kind to explain to a knob like myself how the 2 extra mosfets and new resistor(s) and new diodes(s) would all be connected?

Pete, thanks for leaking your tool steel project, sounds like a great idea.  Do you think 3kW will get you there? :)   If not, Dave suggested possibly using even better mosfets that have 250v ratings that can easily handle 60 volts?  Don't know if these better FETs could handle 50-60amps though, or how other components would comply or handle over 3kW, etc.? --- Dave, do I dare ask if a 3.5Kw (60v 58a) MOD is physically possible and economically feasible with this unit? 
« Last Edit: March 15, 2021, 07:11:02 PM by hightemp1 »

Online davekni

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Existing gate resistors and diodes should work fine with better FETs.  I don't have any specifications for the diodes.  If they work for IRPF260N, they should work for the better FETs too, as they have lower gate charge and lower on-resistance.  Just changing FETs should be fine.

Adding FETs is more tricky.  Wiring inductance can lead to parasitic high-frequency (RF) oscillations.  If you can extend the copper planes of the existing board, then it should work.  I think using better FETs with the existing board is easier and more likely to be successful - why I suggested that initially.

60V 60A should be possible with the 250V FETs I'd suggested IF the inductors are upgraded too.
David Knierim

Offline hightemp1

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Existing gate resistors and diodes should work fine with better FETs.  I don't have any specifications for the diodes.  If they work for IRPF260N, they should work for the better FETs too, as they have lower gate charge and lower on-resistance.  Just changing FETs should be fine.

Adding FETs is more tricky.  Wiring inductance can lead to parasitic high-frequency (RF) oscillations.  If you can extend the copper planes of the existing board, then it should work.  I think using better FETs with the existing board is easier and more likely to be successful - why I suggested that initially.

60V 60A should be possible with the 250V FETs I'd suggested IF the inductors are upgraded too.

Wow, who knew such a cool MOD could potentially be so easy. So rather than the ZVS board being limiting factor, the power supplies may be limiting us from going above 3kW.  However, there seams to be several different used servo type 3kW PSs out there, and lucky for us, many have documentation on tweeking up volts by 10% and since ZVS loves more volts amps will follow so maybe a 20% bump or 3.6Kw PS is possible with the right model of PS?  Getting a KW more power just sounds so much better than getting .5kw more - especially if reliable. :) 

Dave, I just went back and looked at the 250v FET you suggested and it actually is only a 200v model.  When you get a chance please suggest a good 250v FET. Thanks again and so sorry to be such a nuisance.  Promise not to post for another week! :o
« Last Edit: March 15, 2021, 07:33:40 PM by hightemp1 »

Online davekni

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Sorry, typo in my earlier reply #334, now corrected.  I'd listed the same part number twice.  Real 250V option is IXTQ76N25T (or IXTH76N25T).  There are other 250V options too.  IRFP4332PBF is fine, higher gate charge, but still less than IRFP260.  There are more options too if those aren't readily available.

No concern about posting - especially when pointing out a typo that needs fixing.
David Knierim

Offline hightemp1

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Broke my promise David only to say how admirable I think it is that you, Pete and so many others here take the time to help knobs like me out especially considering how valuable your time is.  :)
« Last Edit: March 18, 2021, 08:51:01 AM by hightemp1 »

Offline hightemp1

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Most of the used server-type 3KW power supplies out there are very good ways to power our +2.5kw IHs.  Alternatively, if you have several MOTs lying around like me you could make one.  For a target 3.5kw version it could get complicated though.   To get a 3.5kw rated transformer PS, I am thinking four MOTS may be required.  Reason being, 30 turns of proper gauge wire is about the maximum number of turns you can get for each transfomer, so to get 60V you'd wire two in series - so far so good?  Power-wise, assuming each MOT is equally rated at 1200 Watts, two MOTs in series would only give 2.4kw.  So maybe two more transformers added in parallel would be required, giving 4.8kw?  Pete and company please find the flaws in my thinking.  Another question is -- 4.8kw would require 220v outlet.  All my MOTs are rated at 120v - can a 120v MOT even be used with 220V?

UPDATE:  None of my 120v circuits have 30amp fuses at the panel.  Maybe add a 30amp 120v circuit and do three MOTs in series wired with 20 turns each with heavier gauge wire and still get 3kw?

If you'd like more info on how to properly rewire a microwave transformer check out Pete's YouTube video.
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« Last Edit: April 09, 2021, 06:49:57 AM by hightemp1 »

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April 20, 2021, 01:54:01 PM
post Re: MidiStick Polyphonic USB Midi Interrupter
[Computers, Microcontrollers, Programmable Logic, Interfaces and Displays]
TMaxElectronics
April 20, 2021, 04:53:09 AM
post Re: Project: FreakyDRSSTC MK1
[Dual Resonant Solid State Tesla coils (DRSSTC)]
davekni
April 20, 2021, 02:32:21 AM
post Re: gdt high frequency ring
[Solid State Tesla Coils (SSTC)]
davekni
April 20, 2021, 02:28:12 AM
post Re: Some questions about DRSSTC's, and guidance to build one.
[Dual Resonant Solid State Tesla coils (DRSSTC)]
davekni
April 20, 2021, 12:20:45 AM
post Re: Some questions about DRSSTC's, and guidance to build one.
[Dual Resonant Solid State Tesla coils (DRSSTC)]
MRMILSTAR
April 19, 2021, 09:59:08 PM
post Re: Help for people buying the "12-48 Volt 1800/2500 Watt ZVS induction Heater"
[Electronic Circuits]
petespaco
April 19, 2021, 09:35:16 PM
post Re: Some questions about DRSSTC's, and guidance to build one.
[Dual Resonant Solid State Tesla coils (DRSSTC)]
AstRii
April 19, 2021, 08:48:07 PM
post Re: gdt high frequency ring
[Solid State Tesla Coils (SSTC)]
balazs
April 19, 2021, 05:03:29 PM
post Intensifying screen
[X-ray]
Merces
April 19, 2021, 04:45:03 PM
post Some questions about DRSSTC's, and guidance to build one.
[Dual Resonant Solid State Tesla coils (DRSSTC)]
mrsebe
April 19, 2021, 04:36:43 PM
post Whoohoooooo
[Dual Resonant Solid State Tesla coils (DRSSTC)]
GrantV
April 19, 2021, 12:29:03 PM
post Please, Share SSTC schematics with me
[Solid State Tesla Coils (SSTC)]
hashtala
April 19, 2021, 10:02:46 AM
post What driver to use for first DRSSTC build
[Dual Resonant Solid State Tesla coils (DRSSTC)]
thedoc298
April 19, 2021, 06:04:03 AM
post Re: Mitsubishi CM300DY-24H IGBT
[Beginners]
thedoc298
April 19, 2021, 02:48:40 AM
post Re: Mitsubishi CM300DY-24H IGBT
[Beginners]
Mads Barnkob
April 18, 2021, 08:04:18 PM
post Mitsubishi CM300DY-24H IGBT
[Beginners]
thedoc298
April 18, 2021, 07:10:24 PM
post Re: gdt high frequency ring
[Solid State Tesla Coils (SSTC)]
balazs
April 18, 2021, 01:11:28 PM
post Re: Drsstc Driver Board for Tesla Coil Driver Optic Fiber Splice
[Dual Resonant Solid State Tesla coils (DRSSTC)]
iw1esu
April 18, 2021, 12:26:48 PM
post Re: Mains synced sstc questions
[Solid State Tesla Coils (SSTC)]
Magneticitist
April 18, 2021, 02:36:34 AM
post Re: Help needed with SSTC. First TC build
[Solid State Tesla Coils (SSTC)]
davekni
April 18, 2021, 01:24:59 AM
post Re: Welcome new members, come say hello and tell a little about yourself :)
[General Chat]
mrsebe
April 17, 2021, 07:56:07 PM
post Re: Project: FreakyDRSSTC MK1
[Dual Resonant Solid State Tesla coils (DRSSTC)]
davekni
April 17, 2021, 07:50:17 PM
post Re: Help needed with SSTC. First TC build
[Solid State Tesla Coils (SSTC)]
Maverikie
April 17, 2021, 07:20:58 PM
post Re: Project: FreakyDRSSTC MK1
[Dual Resonant Solid State Tesla coils (DRSSTC)]
GrantV
April 17, 2021, 11:53:37 AM
post Re: Help needed with SSTC. First TC build
[Solid State Tesla Coils (SSTC)]
Mads Barnkob
April 17, 2021, 09:34:02 AM
post Re: Help needed with SSTC. First TC build
[Solid State Tesla Coils (SSTC)]
davekni
April 17, 2021, 05:36:49 AM
post Re: Project: FreakyDRSSTC MK1
[Dual Resonant Solid State Tesla coils (DRSSTC)]
davekni
April 17, 2021, 04:30:36 AM
post Help needed with SSTC. First TC build
[Solid State Tesla Coils (SSTC)]
Maverikie
April 16, 2021, 09:22:47 PM
post HELP .... PLEASE?
[Dual Resonant Solid State Tesla coils (DRSSTC)]
GrantV
April 16, 2021, 10:50:24 AM
post Re: Mains synced sstc questions
[Solid State Tesla Coils (SSTC)]
dexter
April 15, 2021, 10:48:12 PM
post Re: Drsstc Driver Board for Tesla Coil Driver Optic Fiber Splice
[Dual Resonant Solid State Tesla coils (DRSSTC)]
TMaxElectronics
April 15, 2021, 01:57:49 PM
post Re: My 14-stage Cockroft-Walton voltage multiplier
[Voltage Multipliers]
MRMILSTAR
April 14, 2021, 10:56:15 PM
post Re: My 14-stage Cockroft-Walton voltage multiplier
[Voltage Multipliers]
MRMILSTAR
April 14, 2021, 09:34:11 PM
post Re: Single mosfet bifiliar gdt
[Solid State Tesla Coils (SSTC)]
aie212
April 14, 2021, 09:19:51 PM
post Re: My 14-stage Cockroft-Walton voltage multiplier
[Voltage Multipliers]
304er
April 14, 2021, 07:54:38 PM
post Re: My 14-stage Cockroft-Walton voltage multiplier
[Voltage Multipliers]
304er
April 14, 2021, 07:42:50 PM
post Re: Single mosfet bifiliar gdt
[Solid State Tesla Coils (SSTC)]
Mads Barnkob
April 14, 2021, 07:39:14 PM
post Re: Mains synced sstc questions
[Solid State Tesla Coils (SSTC)]
Mads Barnkob
April 14, 2021, 07:35:25 PM

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