Author Topic: Some Starting Questions About My New DRSSTC ???  (Read 6925 times)

Offline ItsChloeUwU

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Some Starting Questions About My New DRSSTC ???
« on: November 24, 2021, 01:42:15 AM »
Hi!

First of all thx for everyone who is willing to help me out on this.

I have some questions to make and understand how things will turn out this way.

So, i recently buyed some nice EUPEC BSM75GB120DN2E3223 used on ebay!
I had it a really good price and with some cleaning with alchaol and a toothbrush i will make them sine agin.. LoL.
They tested them so i know they work, but yeah, i dont really like the nasty looks of them.
So now im planning to make my bridge and from what i understood we have some nice sparks with an half bridge and some voltage doublers that i dont really know how hey work.
For my half bridge (i buyed 2 of them so im doin an half breidge with dublier for now to dont risk wasteing them) i was looking at the Kaizer DRSSTC I from Mads Barnkob and i was planning to use his components from the GDT outputs, so the double 33V Zener diodes the 4.7K resistor 1W and 1.5KE220CA TVS diodes in series.

My first question is.
Are all this components fine for my half bridge?

This said, im going a bit loosed on this because i never had experiences with DRSSTC but is a dream of mine since i was 10 to have one working so i guess its time to get int oit with a lot of help of this forum  ::) :P .

I tryed to follow a video from youtube explaining GDT and how they work and what they do and how. So i have some ferrite toroids that have this specs:

Model:  EPCOS B64290L0674X830
Dimensions: Ø int. 23mm,  Ø ext. 37.5mm x 16.2mm
Material: Ferrite N30
Specs: nH 5750 ±25%, μi (approx.) 4300

And i planned to use 4 of this for OCD and FeedBack and one of this for the GDT, followind the video explained the rateo etc, but i was so lost tbh so would be amazing to knoow a good rateo for the GDT windings.
Im planning to use cat6 ethernet cable for them so i guess would be nice but maybe im wrong.
Since im trying to learn about this please explain me kindly if is all good why and how it is so. I really want to start understand DRSSTC while im playing with some SSTC with IRFP460 LoL.

At this point i sould mention that i have a driver, the UD 2.7C from Steve Ward, Eric Goodchild and Gao Guangyan, and im planning to use this with optic fiber (HFBR-2412TZ) to drive it all in a midi way.

So my secon question is.
How many windings i need to do for the GDT and for the OCD and FeedBack stuff?

Lastly for now, im trying to understand a good secondary ratio, and i saw the amazing DRSSTC guide from Mads Barnkob about the ratios etc.
But the fact is that those IGBT's work on a fairly low frequency as the IGBT guide from Mads Barnkob mentioned.
An user from the olf forum 4hv used to make a coil with this and with a voltage doubler on the half bridge aciveing nearly 2mt of sparks, the username was mmt and the coil he made used my same AWG 30 wire and same IGBT so i was inspired by his desing. But since the forum is nearly dead i tryed to really get into it with even two accounts but they are still not verifying me. So if mmt casually find this, i need you help friendo... plsss... LoL.

So yeah. my other question at this point is.
Whats a good ratio for those IGBTs i just buyed? I was planning to do it with a 11CM tube with 44-55CM of height but it seems too high frequency i guess for those IGBTs.
The amazing coil from the user mmt used 16cm tube with around 50cm height and achived really good resoults so i guess i need another pvc tube? :c

The last question i had for today, is about the voltage doubler.
How dose that work? I never seen one before.. (maybe i did but i didnt know it perhaps?)

I will soon release an update about this with the pictures of the bridge im planning to make and with what components and so you guys can tell me if is good or not perhaps.

THX everyone for your time and i kindly remind you all that im absolutely not an expert but im 100% into this. So i really need help doing this and haveing my time with it.
Its a dream of a little girl that wants to become reality. So i guess... Please help her? LoL..

One last thing. Love You All!

Offline davekni

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Re: Some Starting Questions About My New DRSSTC ???
« Reply #1 on: November 25, 2021, 05:13:17 AM »
Quote
For my half bridge (i buyed 2 of them so im doin an half breidge with dublier for now to dont risk wasteing them) i was looking at the Kaizer DRSSTC I from Mads Barnkob and i was planning to use his components from the GDT outputs, so the double 33V Zener diodes the 4.7K resistor 1W and 1.5KE220CA TVS diodes in series.
Did you mean "Kaizer DRSSTC II"?  I think that is his half-bridge example.

For your slower IGBTs, you will likely need diodes across the 4.7ohm gate resistors R1 and R2 to speed up turn-off.  Such diodes are common in most IGBT bridge designs.  Gate resistance value may need changing to match your IGBTs gate charge and your GDT leakage inductance.

As discussed in several threads here, I suggest leaving off the 1.5KE220CA TVS diodes.  They will fail at much lower voltage (and probably lower energy) than your 1200V IGBTs.  TVS diodes often fail shorted, which will then destroy the opposite IGBT.

Quote
Model:  EPCOS B64290L0674X830
Dimensions: Ø int. 23mm,  Ø ext. 37.5mm x 16.2mm
Material: Ferrite N30
Ferrite saturation flux varies with temperature and field.  Let's presume 0.3T (300mT) for N30 at some reasonable warm temperature.  Core cross-sectional area is ~7mm x ~16mm = 112mm^2.  0.3T * 112mm^2 = 33.6uVs/turn.  This is the voltage*time/turn that will generate 0.3T.  To calculate turns, you need to know gate drive voltage and maximum time.  I'll presume 24V from UD2.7.  Time depends on minimum coil frequency.  I'll presume 50kHz for this example.  At 50kHz, gate drive is high for 10us and low for 10us.  So, turns = 24V * 10us / 33.6uVs = 7.14 turns.  So 8 turns would be enough unless your frequency is below 50kHz.  (Extra turns is not always better, as longer wire increases leakage inductance.  A couple extra turns for margin is fine.)

Quote
Im planning to use cat6 ethernet cable for them so i guess would be nice but maybe im wrong.
Older CAT5 or before is generally better if winding with the cable intact.  CAT6 has a stiff inner core to separate the four twisted pairs, making it difficult to wind.  Removing the twisted pairs is a good option for CAT6 or CAT5 or ...  The pairs can be wound closer to the core for shorter total wire length (less leakage inductance).  Remember to twist lead wires together, again to reduce leakage inductance.

Quote
How many windings i need to do for the GDT and for the OCD and FeedBack stuff?
Current transformers (CT) for OCD and FeedBack can share a single first-stage core, for 3 cores total.  Just make sure that the CT secondaries are shorted if not used.  Winding counts depend on the current you plan to run.  UD2.7 OCD is designed for 3A maximum, so aim for say 2A peak to leave adjustment room.  If you plan to run your coil at 500A peak, then you need a 500A/2A = 250:1 total turns ratio.  (Or, by leaving off one of the UD2.7's OCD 5.1-ohm resistors, trip current is half, 1A, implying 500:1 ratio at 500A peak coil primary current.)  Similar ratios work fine for feedback.
Most CT designs don't run into core saturation uVs limit (33.6uVs for your core) .  However, it is possible to hit uVs limit (core saturation), if second-stage turn count is low.

Quote
The last question i had for today, is about the voltage doubler.
How dose that work? I never seen one before.. (maybe i did but i didnt know it perhaps?)
Look up "voltage doubler" on wikipedia or internet search.
David Knierim

Offline ItsChloeUwU

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Re: Some Starting Questions About My New DRSSTC ???
« Reply #2 on: November 26, 2021, 06:31:56 AM »
Quote
So 8 turns would be enough unless your frequency is below 50kHz.  (Extra turns is not always better, as longer wire increases leakage inductance.  A couple extra turns for margin is fine.)


Quote
UD2.7 OCD is designed for 3A maximum, so aim for say 2A peak to leave adjustment room.  If you plan to run your coil at 500A peak, then you need a 500A/2A = 250:1 total turns ratio. Similar ratios work fine for feedback.
Most CT designs don't run into core saturation uVs limit (33.6uVs for your core) .  However, it is possible to hit uVs limit (core saturation), if second-stage turn count is low.

HI!

First of all super duper thx for your awersome reply!

As i mentioned in my presentation post im totally ou of this world but im willing to really learn everything and i tryed to follow some instructions from Mads guide.

I'm a bit confused when it comes to calculations since i didn't even go to high school or anything so.. would be awersome if you could at least be extra specific on the CT for FeedBack and OCD.
I have to be fully honest... i didnt get nearly any of it...
What i get was that i need to run my UD2.7 Rev. C with 2A at least and max around 3A (im in the 3A range on my current power supply so i am super oky on this) but the part that gets me the most is the windings, im totally not understanding the rateo between windings on it.. and even how to use only 3 of my EPCOS ones to do it all (if is possible OFC), im really confused on this  :/ .
Even the part there you said:

Quote
(Or, by leaving off one of the UD2.7's OCD 5.1-ohm resistors, trip current is half, 1A, implying 500:1 ratio at 500A peak coil primary current.)

I didnt get there is this resistor, maybe im just stoopid but i didnt see it in the UD2.7 Rev. C board :/ ...

Since i dont want to just build a coil from other persons heads but i whant to actually understand my coil and how it works and what i need to care about when i build it.. and following some guides and haveing help and doing my research on this forum to possibly get it working and relaiable running for even long periods of time. could you please explain me or guide me to a site or something that really explains everything super detalied and even for a nooby like me pls? :3

This said. i got the GDT part tho, and im already on my way to build it with around 9-10 turns with 3 wires from the cat cable and before doing the turns i will twist them all thogether tightly since i decided, i guess smartly  ::), to remove the wires from inside so that i can have them much near the core and only use the cables i need for my half bridge.

Also... i know that this might be a stoopid question. but. do i need to make the turns all the same? so its 1:1:1 ? i guess yes.. but... agin.. i want to know why even if i know its right so that i understand this better agin.

New question and even more important i guess for now. I mentioned this before but i dont know if you skipped it on mistake (i know my post was super long sowwy about that) or if you did that on purpose because is too simple and i can understand it alone or if you just dont know it or what... haha... but anyways i would like to have your opinion on this...

im trying to understand a good secondary ratio, and i saw the amazing DRSSTC guide from Mads Barnkob about the ratios etc.
But the fact is that those IGBT's work on a fairly low frequency as the IGBT guide from Mads Barnkob mentioned.
An user from the olf forum 4hv used to make a coil with this and with a voltage doubler on the half bridge aciveing nearly 2mt of sparks, the username was mmt and the coil he made used my same AWG 30 wire and same IGBT so i was inspired by his desing.

So my question is.. knowind from Mads and his amazing work, and from the mmt user on 4hv, that the coil with this igbt is running around 75khz (from the mmt user "f0: 65-85kHz")
with an 11cm pvc pipe and AWG 30 wire, i would have to do a wiers 1:7 ratio to only get around 70-80khz with a huge topload. But since the coil would likely do aroud 1.5-2Mt of sparks i guess would be oky to have it high even if the ratio is not the one Mads suggested in his guide of around 1:4 to 1:5 ... or am i wrong?

Lastly i would like you to check out my post about the strange IGBT that is giveing me headake.. I think you would find it interesting haha..

Love You All!
« Last Edit: November 26, 2021, 06:45:49 AM by ItsChloeUwU »

Offline davekni

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Re: Some Starting Questions About My New DRSSTC ???
« Reply #3 on: November 26, 2021, 07:48:07 PM »
Quote
What i get was that i need to run my UD2.7 Rev. C with 2A at least and max around 3A (im in the 3A range on my current power supply so i am super oky on this) but the part that gets me the most is the windings, im totally not understanding the rateo between windings on it.. and even how to use only 3 of my EPCOS ones to do it all (if is possible OFC), im really confused on this  :/ .
I was referring to current into the UD2.7 OCD input, not the power supply to UD2.7.

Quote
I didnt get there is this resistor, maybe im just stoopid but i didnt see it in the UD2.7 Rev. C board :/ ...
R17 and R28 in the lower left corner of UD2.7 schematic are the OCD CT burden resistors, 5.1 ohms each.  The current transformer (CT for short) transforms primary current from 500A for example down to 2A to feed the UD2.7 OCD input.  This 2A current is rectified by bridge rectifier D4-D7, then to resistors R17 and R28.  The resulting voltage across R17 and R28 feeds comparitor IC7.  If one of R17 or R28 is removed, resistance becomes 5.1 ohms total instead of half that (2.55 ohms), so less current is required from OCD CT to trip OCD and end the burst.

There are many DRSSTC builds documented on this forum and other sites.  Look at their OCD and feedback CT construction, and GDT construction.

Quote
Since i dont want to just build a coil from other persons heads but i whant to actually understand my coil and how it works and what i need to care about when i build it.. and following some guides and haveing help and doing my research on this forum to possibly get it working and relaiable running for even long periods of time. could you please explain me or guide me to a site or something that really explains everything super detalied and even for a nooby like me pls? :3
I appreciate your desire to make your own design.  That is the fun part.  However, DRSSTC design isn't a good place to start learning basic electronics concepts.  If you have a signal generator and oscilloscope, use those to explore how inductors and transformers work.  Wind a single coil of a few turns around your N30 toroid core.  Connect to signal generator and scope voltage as you change frequency.  If you don't have a signal generator, make a simple one from a 555 timer or schmitt trigger inverter.  Once those results start to make sense, feed the signal generator into UD2.7 feedback input.  Then experiment with GDT variations on UD2.7 output.

Quote
Also... i know that this might be a stoopid question. but. do i need to make the turns all the same? so its 1:1:1 ? i guess yes.. but... agin.. i want to know why even if i know its right so that i understand this better agin.
There are some designs using other GDT ratios.  UD2.7 is designed for 1:1:1.  That simple ratio is generally best, allowing winding with twisted pairs for low leakage inductance.

Quote
So my question is.. knowind from Mads and his amazing work, and from the mmt user on 4hv, that the coil with this igbt is running around 75khz (from the mmt user "f0: 65-85kHz")
with an 11cm pvc pipe and AWG 30 wire, i would have to do a wiers 1:7 ratio to only get around 70-80khz with a huge topload. But since the coil would likely do aroud 1.5-2Mt of sparks i guess would be oky to have it high even if the ratio is not the one Mads suggested in his guide of around 1:4 to 1:5 ... or am i wrong?
Are you discussing the ratio of secondary height to secondary diameter?  (Ratios can be of any two numbers, most often here referring to transformer turns ratios, the number of secondary turns / number of primary turns.)  For secondary diameter/height, my DRSSTC is about 1:7.  However, 1:4 or 1:5 would be better.  My 1:7 limits coupling factor before racing sparks occur on the secondary.

Quote
Lastly i would like you to check out my post about the strange IGBT that is giveing me headake.. I think you would find it interesting haha..
Yes, I did see your other post.  I had looked for data before posting my first answer to you.  Didn't find any.
David Knierim

Offline ItsChloeUwU

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Re: Some Starting Questions About My New DRSSTC ???
« Reply #4 on: November 27, 2021, 11:42:08 PM »
Hi,
first of all as always big thx for your help, after a bit of researc and more in depth analisys about other persons etc, i came out with this windings for the OCD and FeedBack CT, 23x23x23 on the tree cores and i will pass one white around two of them from the other one (i think this is how i sould do it for 3 cores only, but since im not sure would be amazing to have confirmation before building them), so in teory i sould now have 529:1 if im not wrong. Thats because i checked my driver and the r28 is empty and the r17 is with a 5.1Ω 5% resistor so following what you said to me i need a 500:1 ratio feedback, and i guess this is how im supposed to do it? if im wrong please currect me on this explaining why... would be great to understand what i calculated wrong!

This said, about the secondary, i opted for a 140mm pipe with 70cm of heigh to that i get the 1:5 ratio from diameter to height of the secondary for better coupling as we discussed and you told me (i even readed some articles explaining how coupling is important so i guess i was terrified of bad resoults since im putting a bit of money into this project so i decided to go all in with this huge secondary haha).

Finally, i did the turns on the GDT and i did 9 turns so that i can go a bit more sure than your suggested 8 since you said a bit more would be fine and 8 looked a bit little for some reason haha.
The wire used was a 0,14 mm² cable (opted to ditch the CAT 6 cable since it was too rigid and i didnt feel comfy in letting it so loose in the inner core of the GDT)

There is a picture of it so that i can be judged by the internet about my silly handed works of winding BEFORE:





There is a picture of it so that i can be judged by the internet about my silly handed works of winding AFTER:





I also decided to pick the cooler for my half bridge that i payed so little after a bit of negotation with the seller.
Can you please tell me if it looks like henaf to cool down the big boy? I will be adding a fan probably too, like a pc fan of 120mm or something like that.








Thx for your amazing help btw and for following my post and project!

Offline davekni

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Re: Some Starting Questions About My New DRSSTC ???
« Reply #5 on: November 28, 2021, 12:53:27 AM »
Quote
i came out with this windings for the OCD and FeedBack CT, 23x23x23 on the tree cores and i will pass one white around two of them from the other one
Yes, I think you understand correctly.  A picture after construction will verify.  Yes, that is for 529:1 final ratio, which should be good for 5.1 ohm OCD burden resistor and for the 51 ohm feedback burden resistor.  (Higher voltage is expected on the feedback input.)

Both GDT pictures look great.  There's no need to keep the wires all together once they leave the core.  Twist the two primary wires together to head one direction (to UD2.7).  Twist each secondary winding lead with itself to head to the two gate-emitter terminals.

BTW, GDT leakage inductance can be even a bit lower if wound with two twisted pairs (four wires total).  One half of each pair is secondary, one for each IGBT gate-emitter connection.  The other half of each pair are wired in parallel to UD2.7 output.  (This is just me being a perfectionist.  Your 3-wire construction will work fine for this relatively-low-frequency coil.)

That heatsink may suffice, but it is not great.  It was designed for passive air cooling (natural convection).  Heatsinks designed for forced-air cooling (fans) have many more fins tightly packed together, often with a thicker base.  Since you have it already, I'd start with that heatsink.  Should work fine for low-duty-cycle testing.  As you increase interrupter duty cycle (increase total power consumption), measure temperature.  If excess temperature limits the power you want to run, then buy a better heatsink.
« Last Edit: November 28, 2021, 01:04:41 AM by davekni »
David Knierim

Offline ItsChloeUwU

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Re: Some Starting Questions About My New DRSSTC ???
« Reply #6 on: November 28, 2021, 02:19:00 AM »

THX for all your kind words...

for the heatsink, before i order it, this one would be way better, right?
Remember that is only one the IGBT that hast togo on it so i guess it would be way better than the black one.. right?|

New cooler:



Offline davekni

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Re: Some Starting Questions About My New DRSSTC ???
« Reply #7 on: November 28, 2021, 04:28:33 AM »
Yes, that one should be much better for forced-air (fan) cooling.  As I said, you could try your existing one initially.  Or get this one to avoid any need to rebuild later.
David Knierim

Offline ItsChloeUwU

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Re: Some Starting Questions About My New DRSSTC ???
« Reply #8 on: November 28, 2021, 09:36:10 AM »
Yes, that one should be much better for forced-air (fan) cooling.  As I said, you could try your existing one initially.  Or get this one to avoid any need to rebuild later.

I guess i will buy both if i can get a nice deal out of it but mainly i will start useing directly the silver one, so that at least i dont waste time haha.

Also, leater today i will wind the secondary probably, and i will wind the OCD and FeedBack CT! So be ready to be cringed haha :P 

Also i will try to do the GDT like you suggested, but i need to understant that message a bit better before (i saw that quickly i admit, but i didnt get it at least at first reading) so if you would be a bit more clear on how to wind it and how to make the connections would be amazing! I really want this coil to be as much perfect as possible!

And also super thx for all your nice words on my GDT and my understanding of the OCD and FeedBack CT ratio etc.
I really worked hard on it to understand it better with research from this forum and googleing around for hours.. and that gived me some results.
So i am super happy that somebody is telling me that i'm doing good and really motivates me to keep understanding and studying it bit by bit... and also.. i feel super duper intelligent knowing i understand more then ever electronics now that i'm totally into this and i feel like a smart little girl  ::) haha.

So yeah... first post without any real question.. i guess you will be happy :P ::) haha.
I feel like i'm really takeing some of your time and knowledge so if i can support you trough a nice little donation or something let me know because you totally deserve it for the time and awersomeness that you are giveing me.. and also.. for the good vibes i get after your messages of knowing that i can do this and tha tim actually even doing great!




OFF TOPIC FOR USER "davekni":

After i started this project with the guy i gived nearly everything to and tough was really the one.. for once...
I just realized that he kind of used me even with all my panic attacks and fears of going out and knowing new people and socializeing etc... and at more than 130km from my home and on a super huge and chotic fair.. he decided to start doing the shi**y guy after he met me... i still dont understand why to this day... but oky... maybe i'm ugly or maybe he is just not interested.. idk.. but long story short he behaved like a pice of shi* and now i'm there doing this all alone by my self... so this coil is not only "a project of a dreamy little girl" but even the revenge i need to take on that guy to let him see that i can do this all alone... so this is really a life goal for me at the moment more than ever to proof that i dont need anyone with me to do it but i can do it all alone by my self with a lot of research.. study.. and some (or a lot) of help from this forum and amazing people like you! I might sound a bit romantic and mushy but thats totally how i feel with people this kind to me like you are... maybe its because life was really shi* with me but yeah.... just... thx... really... you are not only helping me build a coil and understand it by my self little by little... but also helping me to get my life back in some way trough this project... so yeah... super duper thx!💗

« Last Edit: November 30, 2021, 12:23:58 AM by ItsChloeUwU »

Offline Mads Barnkob

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Re: Some Starting Questions About My New DRSSTC ???
« Reply #9 on: November 28, 2021, 08:13:08 PM »
Dave is a real good guy and fast too! He often answers 10 questions before I can find time to read one topic :)

Heat sinks are such an interesting topic, I really should finish my work on the heat sink for Tesla coils article, that has been a draft for some years.

As long as you use force air-cooling, almost any heat sink is usable. Even smaller passive heat sinks show a 7-fold improvement in heat dissipation when using force air cooling on them.

Just for the fun of learning about heat sinks, here is 3 different terms use widely, but has different meanings that are worth knowing.
Conduction - heat transfer through a material or medium
Convection - heat transfer from a surface to a gas or fluid medium
Radiation - heat transfer in the form of electromagnetic radiation
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Offline davekni

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Re: Some Starting Questions About My New DRSSTC ???
« Reply #10 on: November 29, 2021, 12:26:28 AM »
Quote
I guess i will buy both if i can get a nice deal out of it but mainly i will start useing directly the silver one, so that at least i dont waste time haha.
If you haven't purchased the black one yet, don't.  Buy only the silver one.

Quote
Also i will try to do the GDT like you suggested, but i need to understant that message a bit better before (i saw that quickly i admit, but i didnt get it at least at first reading) so if you would be a bit more clear on how to wind it and how to make the connections would be amazing! I really want this coil to be as much perfect as possible!
Since I've tried to describe this winding several times before, with limited success, I finally made a little tutorial post showing how:
https://highvoltageforum.net/index.php?topic=1854.msg13949#msg13949
This design isn't uniquely mine.  It shows up in many builds here, usually in the full-bridge version.  I haven't been able to find any specific instructions, so made the above-linked post.

You are welcome for the help.  It is a good challenge for me to figure out how to explain things without presuming specific prior knowledge.

Thank you to Mads for the compliment.
David Knierim

Offline ItsChloeUwU

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Re: Some Starting Questions About My New DRSSTC ???
« Reply #11 on: November 29, 2021, 10:52:43 PM »
Dave is a real good guy and fast too! He often answers 10 questions before I can find time to read one topic :)

Heat sinks are such an interesting topic, I really should finish my work on the heat sink for Tesla coils article, that has been a draft for some years.

As long as you use force air-cooling, almost any heat sink is usable. Even smaller passive heat sinks show a 7-fold improvement in heat dissipation when using force air cooling on them.

Just for the fun of learning about heat sinks, here is 3 different terms use widely, but has different meanings that are worth knowing.
Conduction - heat transfer through a material or medium
Convection - heat transfer from a surface to a gas or fluid medium
Radiation - heat transfer in the form of electromagnetic radiation

OMG hiiii!!!!!

You are one of my biggest inspirations!
I really have to thank you and say that im a bit of a fan girl over there haha!
Your work and researc on the DRSSTC stuff is amazing and soooo helpfull for me and im pretty sure you are a good person too with those beautiful mustaches haha!
Thx for commenting and yes! Dave (i guess its davekni IRL name) really is a nice person and sooo kind to follow with my updates and always be there to support and help!

I with you the best things with your future projects and life!
Im super happy to have you there on my post!
I followed your works since i was like 13yo or something.. so form me you are a bit like god haha!

Take care and have a wonderful day!

P.S.: I already knowed those terms, but was super kind of you to remind me!

Offline ItsChloeUwU

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Re: Some Starting Questions About My New DRSSTC ???
« Reply #12 on: November 30, 2021, 12:07:59 AM »

Hi agin davekni!

As always you are super duper kind with me and comprensive!

That guide about the GDT was amazing and i might redo my GDT with the last core i have so that i dont need to put in the trash the last one i did. After that i will put there a pic and you maybe would be so kind to tell me wich one will be better.
From what i understood reading and googleing a bit around some of the same designs (idk if im stoopid or what but i did not find so many half bridges with this design on google), the only difference in the GDT that i did, and the style you suggested, is that i have one more whire (so i would have 4 in total going to the driver) that goes into the GDT the same way dose my only one now, so we could say its a parallel cable. Its like if there was a duplicate of it. If thats it and i understood it currectly i will do it then you could judge it maybe!

Also im trying to have a coil with not may colors in the whires because i just dont really like them even if its easyer to understand wich is wich, i prefear to mark them out and have them all white because i estetically care a lot about the coil.

In fact i have a nice project on the secondary that is estetics only that i will describe in some days/weeks to really make my coil stand out!

Sowwy for the late replay, but as i anticipated i was super busy and i did my secondary and my OCD and FeedBack CT.

I will now start doing the diagram for my bridge with the voltage doubler following Mads amazing work once agin in the DRSSTC guide. But i would love to get some help on this since im not an expet buy im trying my best to do it all currectly and all by my self with google and a lot of passion.
So i would like, if its possible, to get it checked and told if the components are all oky or if there can be something better to buy and get the most close to perfection resoult out of it.

I will now post some pics of my secondary, the specs are 140mm x 700 mm (1:5) of winding with a 0.25mm ( = AWG 30) whire and if i did all currectly on the JavaTC, that i will also post a pic of, with the secondary and top load and primary i sould have around 70kHz in the system. Wich is perfectly in the middle range of the user mmt coil with my same IGBTs.

Secondary coil winding "machine" made with scrap wood, progress of winding and final length:












FeedBack & OCD CT as suggested i did 23 turns per each core then i set two on top of each other and i passed one single wire of the front single one inside them and then i soldered and with an heat shrinking thingy i got it insulated, if you tell me is oky, i will proceed to hot glue or with some zipties to lock the cores in place thogether:








JavaTC Project Calculations:







So far i think i did an oky/good job, i just need to coat the secondary with some resin or spry to keep it in place.
I really gived it all with the winding secondary stuff.. some scrap wood and a bit of self locking nuts and bolts i did the winding "machine" (that could even be adapted to a drill with a variac or something slower to with it my your self) and with someone rotating the pipe i winded it with a lot of nails turning black haha.

Next up i will make the "Box" for the coil and i will post some pictures of how i did it, i would like to ask something about this tho.
I saw on the amazing Mads DRSSTC guide that i sould keep everything metallic far from the primary (for heating problems), but i have planned and already bought the pices for the coil box frame in aluminum. and i planned to ground it all so that i could have a "faraday cage" already protecting the components without the need of strange wires or stuff going all around the box. i planned to leave it all open or to cover the sides with dark plexiglass (or normal transparent plexiglass with a black film behind to make it dark).

This said i will only mount the red nice wheels to the base of the box aluminum frame trough a pice of wood or plexiglass as base support for now and that would be it.

I will alsto try to think about a way to make the topload (i already calculated it to be the same 1/4" copper tube as the primary and with 5 turns total to the topload with a break point of the same copper to have a direction from there the sparks will come out) and the cut it by hand or possibly with a laser or 3d printer do the project that i already made a skatch of with my photo software in vectorial form and get it made by some company near me.

When the heatsinks arrive and all the driver components missing come to my house i will mount them and i will then post a pic of the IGBT mount positions before drilling into the heatsink and use the horrible to clean.. messy.. and goopy... thermal paste haha.
I will also post the over all driver when its finished to be repaird to let you guys please help me found out if there is something missing and what i soul in case buy to finish it (i broked it once because a controller fell into it and some components where bent or desolder from the impact so i would need pretty much a full components check.. but everything sould be fine).
« Last Edit: November 30, 2021, 12:12:59 AM by ItsChloeUwU »

Offline futurist

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Re: Some Starting Questions About My New DRSSTC ???
« Reply #13 on: November 30, 2021, 01:19:18 AM »
Dave is a real good guy and fast too! He often answers 10 questions before I can find time to read one topic :)

I must totally agree :D

Dave pretty much covered all of your questions, good luck with the coil!

Regarding the DRSSTC build if you are a beginner in electronics/Tesla coils.. building a DRSSTC is not easy, you use commercially available components partly in a way they are not designed for. The challenge is in the making the coil working with the parts you can get, and there are many parameters of the coil which depend on the choice of the parts. It is possible to build a DRSSTC without previous experience with Tesla coils, but if you are new to SSTCs or DRSSTCs I'd highly recommend gaining a little more experience by building simpler non-resonant SSTC first before moving on to DRSSTC.



Offline ItsChloeUwU

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Re: Some Starting Questions About My New DRSSTC ???
« Reply #14 on: November 30, 2021, 01:50:18 AM »
Dave is a real good guy and fast too! He often answers 10 questions before I can find time to read one topic :)

I must totally agree :D

Dave pretty much covered all of your questions, good luck with the coil!

Regarding the DRSSTC build if you are a beginner in electronics/Tesla coils.. building a DRSSTC is not easy, you use commercially available components partly in a way they are not designed for. The challenge is in the making the coil working with the parts you can get, and there are many parameters of the coil which depend on the choice of the parts. It is possible to build a DRSSTC without previous experience with Tesla coils, but if you are new to SSTCs or DRSSTCs I'd highly recommend gaining a little more experience by building simpler non-resonant SSTC first before moving on to DRSSTC.

I totally get it, and i know that DRSSTC is mainly based on parts you have or you can find for cheap and you need to use them in a non conventional way, and i know that me being not much experienced its not super great.. but i also always wanted to do one coil like this as i said in my introduction of this forum. and i cant wait anymore since i buyed everything (i had a guy i mentioned before that i was supposed to do this with.. but then he rellay turned out a shi**y person so im on my own) with the 90% of expensive components already buyed out.. i just want to try.. i have already a scope too so i can totally learn something at least... if the coil fails... im oky with it.. as long as i really tryed you know... i want to learn makeing things explode more than study books (that i already do a lot googleing around 5-8 hours a day tho)..

Thx for your nice replay anyways! And maybe if i need help.. you could help me out in the future.. or maybe.. i could help you out with non tesla stuff if needed haha!

Offline davekni

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Re: Some Starting Questions About My New DRSSTC ???
« Reply #15 on: November 30, 2021, 06:23:03 AM »
Quote
If thats it and i understood it currectly i will do it then you could judge it maybe!
Yes, I think you understand correctly.  Electrons don't pay attention to wire color, so just mark appropriately.  (May be a bit harder to verify correctness from pictures, however.)  If you look at any of my projects posted here, you will see that I'm entirely into the science, with almost no attention paid to aesthetics :).

Quote
FeedBack & OCD CT as suggested i did 23 turns per each core then i set two on top of each other and i passed one single wire of the front single one inside them and then i soldered and with an heat shrinking thingy i got it insulated, if you tell me is oky, i will proceed to hot glue or with some zipties to lock the cores in place thogether:
Looks good!

Quote
I saw on the amazing Mads DRSSTC guide that i sould keep everything metallic far from the primary (for heating problems), but i have planned and already bought the pices for the coil box frame in aluminum. and i planned to ground it all so that i could have a "faraday cage" already protecting the components without the need of strange wires or stuff going all around the box. i planned to leave it all open or to cover the sides with dark plexiglass (or normal transparent plexiglass with a black film behind to make it dark).
Not sure I have a picture of the frame, but aluminum close to the primary is likely to be a problem.

David Knierim

Offline ItsChloeUwU

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Re: Some Starting Questions About My New DRSSTC ???
« Reply #16 on: December 05, 2021, 12:35:17 PM »

OMG HI!

I'm still alive!

So, i spent the last days really trying to understand voltage doublers and bridges. Also my heatsinks arrived, and they are massive tbh, i will attach some pics so that you can tell me wich one to use, in my opinion che black one sould be henaf but i might be wrongy.

So, i spent a lot of time into the schematics too! And i finally came up with something that seems decent.

Could you please check everything and tell me if i did all righty and if not what and why? Would be amazing!

Also i started really enjoying PCB stuff so i tried to go with SMD components for my IGBT-GDT section of it so that i can make an easy snap in plate to the IGBT low voltage section.

I did everything as it seemed right to me but i'm totally not an electronic engeneer or something. So i could have messed up everything or i could have putted some non oky components on it.

I have to ask what diodes could i put into the voltage doubler tho because i could not find any info about it anywere really for the 230V (maybe my googleing skills are giveing up on me agin.. idk...) i had some ideas but they seemed stoopid so i prefeared to not put anything and kindly ask directly instead of posting something totally wrong that somebody could have followed and done wrong too.

I have to say that i picked some parts from the Mads coils but i repleced the voltages of them in some parts because they seemed really low for my voltage doubler stuff.

I also putted some time into thinking about the box of the coil and i opted for a plastic snap in kind of mount. hopefully with some glue and time it will be done in this week and i can then show you my style on the box.

And i also had problems finding materials for my primary coil since reading from Mads amazing guide the primary can really heat up AF. So i would like you to suggest me a cheap but good material so that i can start doing my primary coil this week or next week too!

Another thing i dont really know about but from the poor datasheet i saw its oky even whitout. Is if i have to use mika insulator for the IGBT plate and heatsink before applaying the therml paste even if its Half Bridge or not.


This question is maybe stoopid but i did not consider this before... i have a single phase 230V at home with around 3kW, so would my coil be able to stay into that range of power or will my house shut down because of contract limitations?

And lastly, i tryed to look up for some soft start electronics to put into the coil to avoid useing my variac (i would like the coil to be as plug & play as possible...) but that thing was really hard for me to understand, like i got the components but i totally didnt get where to hook it up. So if you could put me on the right path... agin... it would be so amazing!

Thx for everything as always! And sorry for the may questions but yeah... i guess till the end, would be just me asking around after hours of googleing and thinking and studing  :-[ . So if you need something for your assistance just dm me and i would be honored to give you what you deserve as i already said once!

Heatsinks with IGBT:





Half Bridge + Voltage Doubler diagram:
« Last Edit: December 06, 2021, 11:05:27 AM by ItsChloeUwU »

Offline davekni

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Re: Some Starting Questions About My New DRSSTC ???
« Reply #17 on: December 05, 2021, 08:27:13 PM »
Quote
in my opinion che black one sould be henaf but i might be wrongy.
Probably fine.  Measure temperature eventually when running at high power.

Quote
So, i spent a lot of time into the schematics too! And i finally came up with something that seems decent.
Could you please check everything and tell me if i did all righty and if not what and why? Would be amazing!
This voltage doubler would be a perfect simple circuit to use for learning analog simulation.  If you really want, I'll give you a direct answer.  However, you will learn much more if you learn by simulation.  Or, try a small low-voltage version.  Use small signal diodes and a white plastic breadboard or other temporary interconnection method and a low-voltage AC source (small transformer such as for doorbell...).  Measure voltage and waveforms with your scope.  Learning will take time now, but the understanding will help you understand more subtle details debugging the finished DRSSTC build.

Quote
I have to ask what diodes could i put into the voltage doubler tho because i could not find any info about it anywere really for the 230V (maybe my googleing skills are giveing up on me agin.. idk...) i had some ideas but they seemed stoopid so i prefeared to not put anything and kindly ask directly instead of posting something totally wrong that somebody could have followed and done wrong too.
Simulation and/or breadboarding will allow you to measure voltage across diodes, so know what voltage rating is necessary.  Same for current, though that is easier in simulation than with breadboarding.

Quote
I did everything as it seemed right to me but i'm totally not an electronic engeneer or something. So i could have messed up everything or i could have putted some non oky components on it.
An ECB is great for gate drive components.  As with GDT wiring, placement of parts and shape of copper interconnect is important to minimize inductance.  Same general rule:  Keep the emitter return copper close to the gate drive parts and copper, such as emitter copper on the bottom side of ECB and gate parts and copper on the top side.  That minimizes loop area, so minimizes inductance.

Quote
Is if i have to use mika insulator for the IGBT plate and heatsink before applaying the therml paste even if its Half Bridge or not.
IGBT bricks include internal insulators.  Do not add mica.  (If you ever work with TO247 parts and need insulation, there are much better materials now.  Mica was common 50 years ago.  Thermal conductivity is low, however, so not a good choice.)  Do use thermal paste.

Quote
This question is maybe stoopid but i did not consider this before... i have a single phase 230V at home with around 3kW, so would my coil be able to stay into that range of power or will my house shut down because of contract limitations?
I presume 230V 3kW is for one outlet, not the rating of electrical service to your entire house.  If so, then you should be fine.  If you draw too much power, the circuit breaker for that one circuit will trip.

Quote
And lastly, i tryed to look up for some soft start electronics to put into the coil to avoid useing my variac (i would like the coil to be as plug & play as possible...) but that thing was really hard for me to understand, like i got the components but i totally didnt get where to hook it up. So if you could put me on the right path... agin... it would be so amazing!
Soft start is generally necessary.  Variac is the most common soft-start method for DRSSTC.  Commercial supplies typically use a resistor (usually NTC thermistor) in series with the line, shorted by relay contacts after bulk capacitors charge.  I'd suggest getting your coil working with a Variac first before tackling a soft-start circuit.

Quote
And i also had problems finding materials for my primary coil since reading from Mads amazing guide the primary can really heat up AF. So i would like you to suggest me a cheap but good material so that i can start doing my primary coil this week or next week too!
I used polycarbonate.  However, my primary coil is a bit warped now after running at 10kW this summer.
« Last Edit: December 05, 2021, 08:28:49 PM by davekni »
David Knierim

Offline Maju

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Re: Some Starting Questions About My New DRSSTC ???
« Reply #18 on: December 05, 2021, 08:53:57 PM »
Hi!

I don't want to be rude  ;D, but your schema has one fatal error and a slightly smaller one (which is not terribly wrong). I think @davekni said everything you need but I'll give you some hints ;)

1. Full bridge rectifier "BR" is completely useless, which furthermore it will make your voltage doubler not working. You need to give the AC to the voltage doubler, in your case you give the DC from the "BR" rectifier.
2. (The smaller "mistake") you don't need to use C3 and C4 capactiors. You can use C7 and C8 as a voltage doubler caps.

Look at the schem of the hafl bridge with the voltage doubler from Mads site (it is simplified): https://kaizerpowerelectronics.dk/wp-content/gallery/2015_01_28_-_drsstc_design_guide/voltagedoublerbridgewithcap.jpg

For voltage doubler caps use big, low ESR electrolityc caps with "screws", rated on 450V (it's a safe value with margin) for 230VAC energy network and 1500uF or higher (higher = better) -  mount them very close to transistors on thick copper or possibly aluminum sheets.
In Mads schem there is a single cap connected next to the tranzistors, in most cases it's a "snubber cap". Very importat special Polipropylene capacitor with very low ESR, rated on 2000V / 1uF (yes, higher uF = better  ;) ) needs to mounted directly to the bricks - many of them are adapted to be mounted directly to bricks of this type with their screws.

Look on the Internet for similar constructions based on the same type of the bridge (half bridge with voltage doubler), it will be very helpful for you, especially in terms of construction and used components. Here are some examples:

https://www.loneoceans.com/labs/drsstc2/

http://www.goodchildengineering.com/tech-design-blog/tesla-coils/drsstc-2

Your bigger heatsink IMO is better due to the heat capacity and better for the future, when you want to add an another brick for a full bridge DRSSTC.


Good luck!
« Last Edit: December 05, 2021, 08:58:12 PM by Maju »

Offline ItsChloeUwU

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Re: Some Starting Questions About My New DRSSTC ???
« Reply #19 on: December 05, 2021, 11:21:11 PM »
Hi!

I don't want to be rude  ;D, but your schema has one fatal error and a slightly smaller one (which is not terribly wrong). I think @davekni said everything you need but I'll give you some hints ;)

1. Full bridge rectifier "BR" is completely useless, which furthermore it will make your voltage doubler not working. You need to give the AC to the voltage doubler, in your case you give the DC from the "BR" rectifier.
2. (The smaller "mistake") you don't need to use C3 and C4 capactiors. You can use C7 and C8 as a voltage doubler caps.

Look at the schem of the hafl bridge with the voltage doubler from Mads site (it is simplified): https://kaizerpowerelectronics.dk/wp-content/gallery/2015_01_28_-_drsstc_design_guide/voltagedoublerbridgewithcap.jpg

For voltage doubler caps use big, low ESR electrolityc caps with "screws", rated on 450V (it's a safe value with margin) for 230VAC energy network and 1500uF or higher (higher = better) -  mount them very close to transistors on thick copper or possibly aluminum sheets.
In Mads schem there is a single cap connected next to the tranzistors, in most cases it's a "snubber cap". Very importat special Polipropylene capacitor with very low ESR, rated on 2000V / 1uF (yes, higher uF = better  ;) ) needs to mounted directly to the bricks - many of them are adapted to be mounted directly to bricks of this type with their screws.

Look on the Internet for similar constructions based on the same type of the bridge (half bridge with voltage doubler), it will be very helpful for you, especially in terms of construction and used components. Here are some examples:

https://www.loneoceans.com/labs/drsstc2/

http://www.goodchildengineering.com/tech-design-blog/tesla-coils/drsstc-2

Your bigger heatsink IMO is better due to the heat capacity and better for the future, when you want to add an another brick for a full bridge DRSSTC.


Good luck!

Dude... i swear... i feel so stupid....

I leterally saw that and said... wtf...

I'm super sorry, i will proceed to upload the currect one...

Thx for makeing me notice... idk how did i fuc*ed up so much... after all i saw ane even the links you sent i followed them... BRUH... i feel so freaking stoopid...

Well... there sould be the correct one now... pls kindly take a look at it and tell me if its wight now... it feels right to me... but i might have done other shi**y stuff.... i feel so stoopid i swear... it was like 12:40 P.M. when i posted it in Italy... and i didnt sleep for hours doing it.. so i fuc*ed up like that... BRUH... i like connected 2 voltage doublers in a wierd way with a full bridge rectifier... BRUUUHHHH i cant belive it.....  :'( :-\

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Re: Some Starting Questions About My New DRSSTC ???
« Reply #19 on: December 05, 2021, 11:21:11 PM »

 


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March 14, 2024, 09:29:06 PM
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[Dual Resonant Solid State Tesla coils (DRSSTC)]
Keybored
March 14, 2024, 09:11:54 PM
post Re: Welcome new members, come say hello and tell a little about yourself :)
[General Chat]
WolfMoonshirt
March 14, 2024, 06:09:27 PM
post Re: No Corona Discharge with ZVS Driver
[Beginners]
MaybeJosh
March 14, 2024, 01:36:35 PM
post Re: No Corona Discharge with ZVS Driver
[Beginners]
MaybeJosh
March 14, 2024, 11:43:23 AM
post Re: Super flat QCW simulation (does this look reasonable?)
[Dual Resonant Solid State Tesla coils (DRSSTC)]
davekni
March 14, 2024, 05:03:41 AM
post Re: No Corona Discharge with ZVS Driver
[Beginners]
davekni
March 14, 2024, 04:56:51 AM
post Re: Bleeder resistor for MMC
[Dual Resonant Solid State Tesla coils (DRSSTC)]
flyingperson23
March 14, 2024, 03:09:45 AM
post Re: Bleeder resistor for MMC
[Dual Resonant Solid State Tesla coils (DRSSTC)]
AstRii
March 14, 2024, 02:23:11 AM
post Bleeder resistor for MMC
[Dual Resonant Solid State Tesla coils (DRSSTC)]
Keybored
March 14, 2024, 01:02:32 AM
post Re: Art student Need help with Plasma Toroid
[Beginners]
toooldforthis
March 14, 2024, 12:01:55 AM
post Re: Art student Need help with Plasma Toroid
[Beginners]
alan sailer
March 13, 2024, 10:22:58 PM
post Re: Simple oscillator instead a ZVS
[Transformer (Ferrite Core)]
Alberto
March 13, 2024, 09:31:22 PM
post Re: Super flat QCW simulation (does this look reasonable?)
[Dual Resonant Solid State Tesla coils (DRSSTC)]
toooldforthis
March 13, 2024, 07:04:35 PM
post Re: Simple oscillator instead a ZVS
[Transformer (Ferrite Core)]
Twospoons
March 12, 2024, 11:55:37 PM
post Re: Simple oscillator instead a ZVS
[Transformer (Ferrite Core)]
Alberto
March 12, 2024, 10:10:41 PM
post Re: Electric insulator. Paraffin wax?
[General Chat]
Alberto
March 12, 2024, 10:08:51 PM
post No Corona Discharge with ZVS Driver
[Beginners]
MaybeJosh
March 12, 2024, 09:13:00 PM
post Re: Anyone know of a good variable driver?
[Beginners]
FPS
March 12, 2024, 06:54:50 PM
post Art student Need help with Plasma Toroid
[Beginners]
lovejdz
March 12, 2024, 11:12:01 AM
post Re: Electric insulator. Paraffin wax?
[General Chat]
Twospoons
March 12, 2024, 01:16:48 AM
post Re: Simple oscillator instead a ZVS
[Transformer (Ferrite Core)]
Twospoons
March 12, 2024, 01:14:35 AM
post Re: New type of hfsstc using self-oscillating current mode class D
[Solid State Tesla Coils (SSTC)]
Perolodzilla
March 11, 2024, 04:18:50 PM
post Re: DRSSTC Questions
[Dual Resonant Solid State Tesla coils (DRSSTC)]
TMaxElectronics
March 11, 2024, 12:50:34 PM
post Re: Electric insulator. Paraffin wax?
[General Chat]
Alberto
March 11, 2024, 08:32:09 AM
post Re: DRSSTC Questions
[Dual Resonant Solid State Tesla coils (DRSSTC)]
flyingperson23
March 11, 2024, 05:01:03 AM
post Re: Electric insulator. Paraffin wax?
[General Chat]
MRMILSTAR
March 11, 2024, 04:23:20 AM
post Re: DRSSTC Questions
[Dual Resonant Solid State Tesla coils (DRSSTC)]
alan sailer
March 11, 2024, 02:30:11 AM
post Re: DRSSTC Questions
[Dual Resonant Solid State Tesla coils (DRSSTC)]
TMaxElectronics
March 11, 2024, 12:37:52 AM
post Electric insulator. Paraffin wax?
[General Chat]
Alberto
March 10, 2024, 11:06:04 PM
post Re: Bleeder resistor in CW multiplier
[Voltage Multipliers]
davekni
March 10, 2024, 06:58:51 PM
post Re: DRSSTC Questions
[Dual Resonant Solid State Tesla coils (DRSSTC)]
davekni
March 10, 2024, 06:49:36 PM
post Bleeder resistor in CW multiplier
[Voltage Multipliers]
Sugarb0y
March 10, 2024, 05:37:39 PM
post Re: DRSSTC Questions
[Dual Resonant Solid State Tesla coils (DRSSTC)]
alan sailer
March 10, 2024, 02:16:25 PM
post Re: Simple oscillator instead a ZVS
[Transformer (Ferrite Core)]
Alberto
March 10, 2024, 02:01:12 PM
post New type of hfsstc using self-oscillating current mode class D
[Solid State Tesla Coils (SSTC)]
Perolodzilla
March 10, 2024, 01:03:51 PM
post Re: [WTS] IGBT, Ferrite, Capacitors, Tools, PSU, Industrial components and parts
[Sell / Buy / Trade]
Mads Barnkob
March 10, 2024, 10:16:38 AM
post Re: DRSSTC Questions
[Dual Resonant Solid State Tesla coils (DRSSTC)]
flyingperson23
March 10, 2024, 07:10:22 AM
post Re: Simple oscillator instead a ZVS
[Transformer (Ferrite Core)]
MRMILSTAR
March 10, 2024, 05:18:03 AM
post Re: DRSSTC Questions
[Dual Resonant Solid State Tesla coils (DRSSTC)]
alan sailer
March 10, 2024, 04:50:13 AM
post Re: DRSSTC Questions
[Dual Resonant Solid State Tesla coils (DRSSTC)]
davekni
March 10, 2024, 03:42:28 AM
post Re: Simple oscillator instead a ZVS
[Transformer (Ferrite Core)]
Twospoons
March 10, 2024, 12:05:09 AM
post DRSSTC Questions
[Dual Resonant Solid State Tesla coils (DRSSTC)]
alan sailer
March 09, 2024, 10:40:11 PM
post Simple oscillator instead a ZVS
[Transformer (Ferrite Core)]
Alberto
March 08, 2024, 10:49:24 PM
post Re: Frequency
[Transformer (Ferrite Core)]
Alberto
March 08, 2024, 10:22:59 PM
post Re: 160mm DRSSTC II project | Questions
[Dual Resonant Solid State Tesla coils (DRSSTC)]
Mads Barnkob
March 08, 2024, 08:22:34 PM
post APC Smart UPS 450 Watt, for Server 19" Rack 1U, Teardown
[Electronic Circuits]
Mads Barnkob
March 08, 2024, 04:07:44 PM
post Re: 160mm DRSSTC II project | Questions
[Dual Resonant Solid State Tesla coils (DRSSTC)]
Late
March 08, 2024, 11:56:11 AM
post Re: CM400 Induction Heater
[Electronic Circuits]
petespaco
March 08, 2024, 01:59:43 AM
post Re: Frequency
[Transformer (Ferrite Core)]
davekni
March 07, 2024, 11:35:01 PM
post Re: Frequency
[Transformer (Ferrite Core)]
Alberto
March 07, 2024, 11:00:03 PM
post Re: Unknown Diode Replacement
[Beginners]
davekni
March 07, 2024, 10:55:40 PM
post Re: CM400 Induction Heater
[Electronic Circuits]
davekni
March 07, 2024, 10:46:42 PM
post Re: Frequency
[Transformer (Ferrite Core)]
davekni
March 07, 2024, 10:23:27 PM
post Unknown Diode Replacement
[Beginners]
Luca
March 07, 2024, 09:55:48 PM
post Re: GDT Driver
[Electronic Circuits]
Mads Barnkob
March 07, 2024, 09:55:04 PM
post Re: CM400 Induction Heater
[Electronic Circuits]
markus
March 07, 2024, 05:07:37 PM
post GDT Driver
[Electronic Circuits]
reklm
March 07, 2024, 04:17:12 PM
post Re: Frequency
[Transformer (Ferrite Core)]
Alberto
March 07, 2024, 01:03:47 PM
post Re: CM400 Induction Heater
[Electronic Circuits]
davekni
March 07, 2024, 05:12:31 AM
post Re: Secondary Splicing
[Dual Resonant Solid State Tesla coils (DRSSTC)]
Benjamin Lockhart
March 07, 2024, 04:45:02 AM
post Re: CM400 Induction Heater
[Electronic Circuits]
petespaco
March 07, 2024, 04:32:17 AM
post Re: Secondary Splicing
[Dual Resonant Solid State Tesla coils (DRSSTC)]
davekni
March 07, 2024, 03:43:25 AM
post Re: DIY induction guns? (warning:long)
[Induction Launchers, Coil Guns and Rails guns]
Michelle_
March 07, 2024, 03:22:34 AM
post Secondary Splicing
[Dual Resonant Solid State Tesla coils (DRSSTC)]
flyingperson23
March 07, 2024, 02:35:54 AM
post Re: CM400 Induction Heater
[Electronic Circuits]
davekni
March 07, 2024, 01:19:03 AM
post Re: First DRSSTC Build Log
[Dual Resonant Solid State Tesla coils (DRSSTC)]
davekni
March 07, 2024, 01:06:15 AM

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