High Voltage Forum
Tesla coils => Dual Resonant Solid State Tesla coils (DRSSTC) => Topic started by: erdal on October 15, 2018, 02:35:19 PM
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Hello Again,
I started my work for 2. drsstc. It will be slightly larger in size.
According to my plans;
~100 Khz secondary res.
~450 - ~650 Amps. OCD
IGBT: CM200DU-12NFH (I bought) full bridge 340 v. DC bus voltage
MMC: 8 parallel 3 serial 0.1 uf 2000v MMC (total 0.2506 uf, 6000 v. 72 A. rms, 800 A. peak)
Secondary: 110 mm dia PVC, ~2000 turn @ 0.2 mm enamelled copper wire
Primary: 0.635 mm copper tube, 5-6 turn. Flat spiral design, strike rail by 9 mm copper tube
Lower pedestal: Table from IKEA :)) (I bought)
Topload: 10x50 cm toroid
Edit: Adding Toroid pictures,
(https://highvoltageforum.net/proxy.php?request=http%3A%2F%2Fi64.tinypic.com%2Fi6f29g.jpg&hash=e3bc64e27dbb82561cda4f9560245196cb84f689)
(https://highvoltageforum.net/proxy.php?request=http%3A%2F%2Fi64.tinypic.com%2Fk4a3w6.jpg&hash=9bd7eedae0d9f2723d8c1de03dcd9d02bee97f03)
I shared some pictures in attachments
I will share the results and construction phases here..
Kind regards,
Erdal
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Solid planning and a design where there is no obvious errors, you will make a great coil here and one that looks stylish on that roller table :)
Winding a primary coil through holes like that goes smooth for the first turn, then it will start locking up and 2-3 turns in you can only move it a cm at a time, so my advise is to make those holes bigger than a snug fit for the primary coil tubing.
What driver are you going to use?
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Hi Mads,
I'm going to use UD2.7, which I made a little change on. I added the IXYS IXDD430YI to the output. It's 30 amps gate driver with low voltage (under 12.5 v) detect. I have coilcraft 7M3-123 and 7M3-153 for phase lead adjustment. but I guess it won't come out enough. So I bought the slot7 empty core. If the tubing in the primary coil gets stuck in the holes, I can expand a bit. don't want to get too wide
(https://highvoltageforum.net/proxy.php?request=http%3A%2F%2Fi65.tinypic.com%2F289vuwx.jpg&hash=e43fd8518a7f478dc17aaab23cf1963cd7efd966)
IGBTs have arrived, bus capacitors and heatsink are also ready
(https://highvoltageforum.net/proxy.php?request=http%3A%2F%2Fi65.tinypic.com%2F2zdwsvn.jpg&hash=e60c078b63b43ddf87cc011e12f60171d1381e4a)
(https://highvoltageforum.net/proxy.php?request=http%3A%2F%2Fi65.tinypic.com%2Fhwbex3.jpg&hash=a3e194a3b587e0138c8db96e4c7ad6031c4273ab)
I will use copper strip (25x3 mm) at dc bus design, two parallel 2200/400 bus caps
Two 1.5 uF, 1000v snubber con.
(https://highvoltageforum.net/proxy.php?request=http%3A%2F%2Fi66.tinypic.com%2F2rxv47p.jpg&hash=2993c16ef2a9778d79b7ef0563d3c4cc64d68b19)
my toroid supplies are also ready;
(https://highvoltageforum.net/proxy.php?request=http%3A%2F%2Fi64.tinypic.com%2F16m69o3.jpg&hash=61868922fc3ffb1574266f0a5b37440c146da1de)
And my primary tubes and secondary PVC
(https://highvoltageforum.net/proxy.php?request=http%3A%2F%2Fi67.tinypic.com%2Ffyhbn8.jpg&hash=4dd81f267d89e0bb17e078b2a55d9962cc211973)
only their assembly remains :D
Erdal
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Hi,
There are some questions that I think of in design;
1- Is it better than the single big gdt for full bridge or is it a small two gdt for every half bridge? which one?
(https://highvoltageforum.net/proxy.php?request=http%3A%2F%2Fi65.tinypic.com%2Fwcegw3.jpg&hash=8ce592215eef1336a90a33a11dd56a985f21ed66)
2-I know rf ground will not connect to the home main ground. Where are the main supply ground? I want to use EMI filter in AC main input. It's ground (Y1 caps) where to connect? The main ground should be float? nowhere to connect to any place?
(https://highvoltageforum.net/proxy.php?request=http%3A%2F%2Fi65.tinypic.com%2F2napqhg.jpg&hash=d10e63941d6ec039a4593df9a360d5d311cd8117)
3-How to connect the bus cap to bridge? Bus Cap 1 connect positive and Bus Cap 3 connect negative (Long wire, red in picture) or positive and negative connect center Bus Cap 2 (short wire, blue and black in picture)
(https://highvoltageforum.net/proxy.php?request=http%3A%2F%2Fi67.tinypic.com%2F2dr77lz.jpg&hash=4b092d0e7256bcb6d58b3c7fa362410d93f7bb6c)
Erdal,
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Lots of good pictures there, its nice to get the full view of all parts and what you are building.
The topload ducting that you got, it looks like metallized plastic film and be aware that it has a very low melting point if you have a hot breakout point. I would recommend using a all aluminium flexible ducting instead.
The GDT split is only done for large bricks and I think its only a matter of load sharing a bit, lessen risk of saturation etc, I am not too sure on this, but for CM200 a single GDT will do fine.
You need a good RF ground to lead of the discharge currents but you can also connect your mains ground to the same busbar, just do not use the mains ground for RF ground, the long path of a mains ground will not do anything good for your coil, house, other electronics plugged in etc.
I am not too sure what you are asking about with the capacitors? Are you putting 3 in series to meet voltage specifications of the bus?
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Hi Mads,
I use 3 2200uf/400v total 6600 uf/400v. Each Irms 8.6 amps, totally 25.8 Amps. 2 of them are enough, but I'll use 3 to be symmetrical.
I wanted to say that; Do I extend the path and connect the cables coming from the bridge to the outermost capacitors? (like your pictures) Or do I connect the middle capacitor?
(https://highvoltageforum.net/proxy.php?request=http%3A%2F%2Fi63.tinypic.com%2F21o95yr.jpg&hash=609147585058f566239d67a2d0fd7e216f77c6e3)
My design;
(https://highvoltageforum.net/proxy.php?request=http%3A%2F%2Fi65.tinypic.com%2Fodc13.jpg&hash=52e3b762f2aa9cc50a7c3f72e3884e13bd0a681d)
Topload, i don't like it too, i'll change it if i can.
I started to wrap the secondary coil ;)
(https://highvoltageforum.net/proxy.php?request=http%3A%2F%2Fi65.tinypic.com%2F2zrdhu9.jpg&hash=71ff43b586921a56444b779228ab1f74a8093cb8)
Erdal
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As long as you place it like "capacitor - IGBT - capacitor - IGBT - capacitor" you do not need to worry about current paths, as you can not get them any better than that, when mounted directly on the busbar.
The illustration is to show that you need to uphold even current path, to try to even our current sharing between the capacitors. Had you put all the lytics on one side of the IGBTs, that first would supply the most current etc. The illustration does not show that you have to extend anything or use wires, but no matter what you do, you need even current paths.
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I finished topload with new aluminum flex tubes
(https://highvoltageforum.net/proxy.php?request=http%3A%2F%2Fi66.tinypic.com%2F4vqlxj.jpg&hash=d26d33746697cbc0ce3708f225446b578ab9e495)
(https://highvoltageforum.net/proxy.php?request=http%3A%2F%2Fi66.tinypic.com%2F9jnexy.jpg&hash=06f22e4981ccf52773486d7cdb40d34f160c7bbb)
Inverter, driver, 220v/30 watt fan, GDT, 50A/1000v bridge etc.
(https://highvoltageforum.net/proxy.php?request=http%3A%2F%2Fi64.tinypic.com%2F2he91dv.jpg&hash=cd27948a5af5906d1ed8f4b0d928f44329adeb97)
(https://highvoltageforum.net/proxy.php?request=http%3A%2F%2Fi66.tinypic.com%2F24c7cqw.jpg&hash=a360369c9e2a7febd1ab2cfbcbdd4833bf669b0c)
Secondary winding finished. This time I gained experience. No any loop or cross wire :)
(https://highvoltageforum.net/proxy.php?request=http%3A%2F%2Fi66.tinypic.com%2Fk50pdg.jpg&hash=d200ed5ed32263a684a4d2e22e00ad550d0b44ee)
(https://highvoltageforum.net/proxy.php?request=http%3A%2F%2Fi67.tinypic.com%2F359hfdh.jpg&hash=3d241db44aedf8ff5a02814f25f51acd4ad3457b)
Waiting for primary brackets. I guess I'll start first tests next week :))
Edit: adding secondary images
my inverter is finished. Should I add tvs diode? cm200du-12nfh 600 volt igbt, 325 volts bus voltage max. i will use
(https://highvoltageforum.net/proxy.php?request=http%3A%2F%2Fi66.tinypic.com%2Fxo13pc.jpg&hash=1711e45548d2ce3631e50de93aa39241fbe1c652)
MMC, 8 parallel, 3 serial 0.1 uf. According to my measurements 0.246 uf
(https://highvoltageforum.net/proxy.php?request=http%3A%2F%2Fi65.tinypic.com%2F2wf7b6p.jpg&hash=3af6f765db0b4b7c4cbfde6dba1a6b69bf34fcfa)
Last edit: primary construction
(https://highvoltageforum.net/proxy.php?request=http%3A%2F%2Fi67.tinypic.com%2F2mhedsz.jpg&hash=8504bfb6731edd825f68b9459a0186b3b0c94e90)
(https://highvoltageforum.net/proxy.php?request=http%3A%2F%2Fi64.tinypic.com%2Fvoc56u.jpg&hash=1a13ed877417faa9829b83bfd7cc2d2edf18486c)
Erdal
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You are getting some good progress in very few days :)
You don't need TVS on a small busbar bridge like that, they are not fast enough and those two snubber capacitors will do the job just fine.
I am a little curious about the temperatures of your electrolytic capacitors, if the middle one will heat up faster than the two on the sides, we will see at test.
I only got one critique point on the MMC, they are way too close together for proper cooling, but again, wait till test and see if its even a problem.
How many layers of varnish did you give the secondary coil?
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Hi Mads,
thank you for your answer and comment :)
How many layers of varnish did you give the secondary coil?
currently only 1 layer.. I'll take a few layers more
I installed the driver and fb/ocd transformers
(https://highvoltageforum.net/proxy.php?request=http%3A%2F%2Fi68.tinypic.com%2Fjt0001.jpg&hash=3da9283477f86b7d7f304f2f181581edff0bcd40)
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Hi,
I finished the secondary coil and the strike rail.
I'm afraid for the first run :)
(https://highvoltageforum.net/proxy.php?request=http%3A%2F%2Fi68.tinypic.com%2F1zv8umh.jpg&hash=7f7dafc0febe3877effec5e38c8c0cf314ec0093)
(https://highvoltageforum.net/proxy.php?request=http%3A%2F%2Fi64.tinypic.com%2F9u5geu.jpg&hash=cd8e57d42d4c888b4a4dd3a19ad799afeb14c6c7)
(https://highvoltageforum.net/proxy.php?request=http%3A%2F%2Fi64.tinypic.com%2F2s1690p.jpg&hash=4d286a0f85f84af19e97c5a6841c16fbf094898d)
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Hi,
my secondary coil was damaged :-\
Because, a long wire inside pvc
I started the new secondary winding
(https://highvoltageforum.net/proxy.php?request=http%3A%2F%2Fi67.tinypic.com%2F9zllhf.jpg&hash=147ae9031ca99ac887b3d28e9887c7bc0b750c0b)
(https://highvoltageforum.net/proxy.php?request=http%3A%2F%2Fi63.tinypic.com%2F2qm1ca1.jpg&hash=e7dbe33f3e4711d372e2e660932dd6703ebc8d5c)
(https://highvoltageforum.net/proxy.php?request=http%3A%2F%2Fi68.tinypic.com%2F2uos3nm.jpg&hash=160a9051d3001cd3685fcceebfd577cb7658c539)
Test with old coil, resonance not tuned
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Congratulations on first light and a working coil! But a shame with a destroyed secondary coil.
What kind of "long wire" was it you had inside of the secondary coil?
How did the coil form look on the inside?
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Hi Mads,
What kind of "long wire" was it you had inside of the secondary coil?
Secondary coil bottom ending wire so long. looping into the pvc and touched secondary inside pvc :)
(https://highvoltageforum.net/proxy.php?request=http%3A%2F%2Fi68.tinypic.com%2Fa4rdi8.jpg&hash=44c86befd8a27d842128bafa5a0e3c3236787a99)
I use coilcraft 7M-153 for phase lead slot7, but i can't adjust phase lead, still overshoot on IGBTs E to C. Oscilascope pictures below, Primary ~104 khz, ~120 vdc bus voltage
(https://highvoltageforum.net/proxy.php?request=http%3A%2F%2Fi63.tinypic.com%2F64duh0.jpg&hash=45efbb95b27a1bd2ae9a0a39d7ba27c97c0c72b3)
(https://highvoltageforum.net/proxy.php?request=http%3A%2F%2Fi67.tinypic.com%2Fnfs8xu.jpg&hash=2cf5a51ce00d299fd3e87e4601fe9153ac407371)
(https://highvoltageforum.net/proxy.php?request=http%3A%2F%2Fi67.tinypic.com%2F260vi11.jpg&hash=acbca2760f6287321af53c8928e944b47605a3a4)
IGBT's cold, MMC's cold, Bus caps are cold, secondary cold no any heating parts at 160 v bus voltage except for primary
Not adjusting primary with new secondary. Low power test. No any sparks look but good sound quality
me and my DRSSTC II :))
(https://highvoltageforum.net/proxy.php?request=http%3A%2F%2Fi66.tinypic.com%2Frlgjdj.jpg&hash=36953b252d199456047f6b374d92368bf0f278ea)
Edit, Tuned interrupt. Only 115v AC, 160v DC, OCD=500A. sparks at ~80 cm ;D
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Hi,
I changed CT's. Large AL and sizes. phase lead adjusting wonderful now. :)
160 volt DC bus voltage, ~95 khz primary
(https://highvoltageforum.net/proxy.php?request=http%3A%2F%2Fi64.tinypic.com%2F4u9v79.jpg&hash=07a94e8605c7ee2d086b97ca16214d168fad1744)
I use 7M3-153 coil + 51R for phase lead. 1 nf for FB comparator
(https://highvoltageforum.net/proxy.php?request=http%3A%2F%2Fi66.tinypic.com%2F2cgzam8.jpg&hash=9bdc9b59bb0c69c34f62b9757a85c20add41bd17)
I think, IXYS IXDD430YI drive better than FDD8424+UCC
one last question left;
How many amps can I run CM200s at most? :))
Primary at test video
160 v ac, 220 v dc bus voltage. Levan Polkka
115 V ac Burst Mode
Erdal,
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That was quite a piece of wiring having waving around inside the coil form, really did a job on the inside. Did you discard the coil and form totally and started from scratch with new materials? Can I use your picture in my secondary design guide as a malfunction example?
Could you please tell the specifications of the GDT that gave your switching spike problems and the specifications for the new one that helped the problem, I would like to see what difference in Al, material etc. it is.
Low voltage testing can also be mischievous, as the output capacitance of the IGBT is always the same, it will result in a switching spike that has the same amplitude at low voltage testing as at full voltage, so testing a low voltage that spike can look 2-3 times bigger than your inverter output voltage, but when you are at full voltage it might only correspond to 10%.
Alex Yuan pushed some CM200 bricks up to 850A and his MMC died before the bricks did :) See bottom of page here: http://kaizerpowerelectronics.dk/tesla-coils/drsstc-design-guide/igbts/
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Hi Mads,
Did you discard the coil and form totally and started from scratch with new materials?
Yes, I left aside the damaged coil then winding the new coil.
Left new, right damaged coil.
(https://highvoltageforum.net/proxy.php?request=http%3A%2F%2Fi68.tinypic.com%2Ffwmzc9.jpg&hash=9bf9a947f69a624fbd2ffab2803bea3eae4f1c64)
Can I use your picture in my secondary design guide as a malfunction example?
of course ;)
Could you please tell the specifications of the GDT that gave your switching spike problems and the specifications for the new one that helped the problem, I would like to see what difference in Al, material etc. it is.
My GDT CF197 material, 49x32x19 mm. Initial Permeability is 7000, AL value is 11500. CAT5 cable, total 15 turns. 5.4 ohm serial resistor on GDT's primary for eliminate gate spikes.
Green coated toroids new CTs. 36x23x15 mm, CF199 material, Initial Permeability is 9000, AL value is 12000. Old T130-26 yellow/white.
(https://highvoltageforum.net/proxy.php?request=http%3A%2F%2Fi67.tinypic.com%2Fsvjokp.jpg&hash=21b8a2ee7bc2223f99741f9623711f903b44df29)
(https://highvoltageforum.net/proxy.php?request=http%3A%2F%2Fi66.tinypic.com%2F1zyzevc.jpg&hash=07395857da4b2a02f2f67dccfce6f49ed86786bf)
Low voltage testing can also be mischievous, as the output capacitance of the IGBT is always the same, it will result in a switching spike that has the same amplitude at low voltage testing as at full voltage, so testing a low voltage that spike can look 2-3 times bigger than your inverter output voltage, but when you are at full voltage it might only correspond to 10%.
It's a beautiful knowledge..
Alex Yuan pushed some CM200 bricks up to 850A and his MMC died before the bricks did :) See bottom of page here: http://kaizerpowerelectronics.dk/tesla-coils/drsstc-design-guide/igbts/
My cm200-12nfh 600 volts version. Therefore, I can apply a maximum of ~350 volts bus voltage. I think it will be a ground strike when I give it around 340 volts bus voltage, 650-700 Amps OCD. I don't need more:)) (If I use a larger secondary coil and the cm300du-24f IGBT, it becomes a really powerful drsstc along with the voltage doubler :) )
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Hi,
I made some small changes;
-I've increased the GDT winding by 1 turn. Now total 16 turn CAT5e
-I reduced the primary serial resistance of GDT from 5.4 ohm to 2.7 ohm
-I replaced the FB and OCD CT with a slightly larger 45x26x15 pc40 material (like fairrite 77 or epcos/tdk n87) toroids. 1/625 turn ratio
-OCD setting ~700 amps
-midi interrupter max ontime increased from 100 us to 150 us :)
-MMC changed 8 parallel 3 serial 0.1 uf 2000 v to 9 parallel 3 serial 0.1 uf 2000 v. (72 amps irms/ 800 amps peak to 81 amps irms/900 amps peak total) finally measured 0.2775 uf
after these changes;
-the IGBT gate signal was perfect
-at 151v bus voltage, max peak voltage 220 volts at IGBT E to C. I think, that my target at 325 volts bus voltage, will be a maximum of 450 volts on IGBTs. It looks good for the health of the IGBTs.
I'm gonna make some noise this weekend :D
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Hi,
OMG!! Final test. Great sparks, up to 1 meters :)
700 amps OCD
320 volt bus voltage
150 us on time
200 bps
(https://highvoltageforum.net/proxy.php?request=http%3A%2F%2Fi68.tinypic.com%2F245eueq.jpg&hash=70c019385dc8c5404b22d188f5347c727eaf1522)
below I added some close-up shots;
(https://highvoltageforum.net/proxy.php?request=http%3A%2F%2Fi68.tinypic.com%2F21mbzud.jpg&hash=6a1f16e0e72291fd17fad93513c04b5ea1b44bb5)
inverter, mmc, bus caps, IGBT's etc.;
(https://highvoltageforum.net/proxy.php?request=http%3A%2F%2Fi64.tinypic.com%2Fcuyhl.jpg&hash=5022bbd13c2f647fa76c5510ea2dec9e673d0380)
CT's and main supply 23.5 volt ac toroid transformer;
(https://highvoltageforum.net/proxy.php?request=http%3A%2F%2Fi64.tinypic.com%2F552mg4.jpg&hash=ad11600fd07e748afa33eb0a53c40d110ca3fee2)
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Congratulations on a good full power run!
Did you get to record any video of it?
Your MMC upgrade will do you good for long run times and MIDI playing. Thanks for providing more pictures and details on the GDT/CT materials. That Ikea table makes for a good looking Tesla coil base!
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Hi Mads,
I could not record the video because I tried inside at the home. It's make very dangerous sparks :)) i just took some photos. I plans to record test videos outdoors
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Hi again :D
Full power @ 700amps 325 volts in open air tests ;D
I am planing to changing IGBT’s CM200 to CM300, 600v to 1200v with voltage dublicate ;)
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i don't know how i missed the original build but this is awesome! i love the simple ingenuity behind the ikea desk. it's truly an amazing looking coil
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THNX oneKone :))
Misson Impossible 700 amps OCD, 340 v bus voltage
When johnny comes marching back home
mmc capacitors fail after long tests :P
My new mmc design. each 0.1 uf, 1200 volts, 8 ampers irms, 12 parallel 5 serial total 60 caps. 0.24 uf 6.000 volt 96 amper irms
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These capacitors are also less sturdy than the CDE 942C series or snubber MKP pulse capacitors, so failure on such a MMC is expected if it does not have a large overhead for voltage and current specification.
Your new MMC layout is problematic, the inner capacitors will not be able to radiate the heat from their losses, so they will heat up faster than the outer ring of caps and will fail before the others due to temperature changing their characteristics.
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I agree, and then if the inner caps fail the other caps fail consequently (avalanche effect).
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Hello All,
Not work! :-\
I changed the MMC, bus voltage ok, driver ok, but nothing any sparks.
Fuse not blown, no any shortcut at IGBTs
what would be the reason?
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Hello,
Now working :)) one of IGBT is death. G to E is 155 ohm :(
I changed CM200DY-12NF to CM300DY-12NF. Can i increase 700 amps to 900 amps at OCD?
Thank you
Erdal
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I still recommend that you do a Fmax2, switching loss calculation to make sure that the CM300 can withstand 900A at 100 kHz, it is a much higher frequency than CM300 is usually used at. I think the highest recorded I got on my page is 700A at 72 kHz by loneoceans.com
Good to see that you found the defective IGBT brick, how about the gate resistor/zener diode, were they damaged aswell? I often saw this problem when a IGBT died.
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I see that you're using the 600V rated CM300, these should be a lot faster than the 1200V ones, so I suspect that 100kHz/900A will be ok, though at the upper limits of what you can do with them.
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I still recommend that you do a Fmax2, switching loss calculation to make sure that the CM300 can withstand 900A at 100 kHz, it is a much higher frequency than CM300 is usually used at. I think the highest recorded I got on my page is 700A at 72 kHz by loneoceans.com
I thought 900 amps was high, I decided not to exceed 700 amps for CM300 s. I plan to reduce the secondary coil by about 80 - 85 kHz.
Good to see that you found the defective IGBT brick, how about the gate resistor/zener diode, were they damaged aswell? I often saw this problem when a IGBT died.
yes, the zeners are dead too
I see that you're using the 600V rated CM300, these should be a lot faster than the 1200V ones, so I suspect that 100kHz/900A will be ok, though at the upper limits of what you can do with them.
Yes, the CM300 is from 600 volts. My bus voltage is 325 volts. if I design a new secondary and lower the frequency, I can try to increase the current
New CM300 test, Metallica Unforgiven
The Final Countdown
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Hi,
Here is my new secondary winding. 110 mm dia to 125 mm dia PVC pipe. Winding length 48.5 cm to 53.5 cm. New resonant freq.= 86-87 khz.
New MMC design 15 parallel 5 serial 0.1 uf 1200 volt snubber caps. 0.3 uf, 6000 volt 120 amps IRMS
Working very well ;)
Erdal,
(https://i.ibb.co/vcFXRVH/tesla.jpg) (https://ibb.co/NFvTbts)
(https://i.ibb.co/2qP50rC/thumbnail-IMG-0834.jpg) (https://ibb.co/Q9nX7VT)
(https://i.ibb.co/Ycqxx6q/thumbnail-IMG-0851.jpg) (https://ibb.co/3pLnnwL)
(https://i.ibb.co/283yFJB/thumbnail-IMG-0864.jpg) (https://ibb.co/XyxbWHT)
(https://i.ibb.co/cD22DW7/thumbnail-IMG-0873.jpg) (https://ibb.co/QrYYrW1)
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Since you wanted to go up in peak current, upgrading your MMC and secondary coil is a wise choice.
Even though the secondary is just making the topload sit 10 cm taller, it will make a difference in regard to avoiding too many strike rail hits.
Your MMC still seems to be a stacked pyramid, how is the capacitors in the middle holding up with temperature after playing MIDI?
Keep sparking!
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Hi Mads,
My pyramidal MMC design is not a good idea for inner caps temperature. I use for short time tests, because i found that caps in local stores and they are quite cheap.
The new mmc design will be as follows;
(https://i.ibb.co/gSp3mHd/mmc2.jpg) (https://imgbb.com/)
(https://i.ibb.co/zXgFwF5/mm3.jpg) (https://ibb.co/tq6z5zh)
(https://i.ibb.co/zG9Mk2q/mmc.jpg) (https://ibb.co/SRYjLmF)
(https://i.ibb.co/BPTnkp1/mmc4.jpg) (https://imgbb.com/)
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Hello all,
New work at the weekend. first, my final mmc design: 3 serial 14 parallel totally 42 snubber caps with 3D printing saperator. 6.000 volt, 126 amps Irms, 0.466 uf
(https://i.ibb.co/GvPbGMX/mmc.jpg) (https://ibb.co/SXv9Hm2)
(https://i.ibb.co/1z0WYtK/thumbnail-619fcb57-8bef-4d16-a785-203774f56f93-1.jpg) (https://ibb.co/LN07DX6)
(https://i.ibb.co/9N4x8Bc/thumbnail-IMG-1189.jpg) (https://ibb.co/pxKH0Nb)
(https://i.ibb.co/zh3y9XZ/thumbnail-f06c3d5b-fe6a-477d-9770-00fe5002396b.jpg) (https://ibb.co/qMHtqNp)
(https://i.ibb.co/c8kvnJq/thumbnail-IMG-1201.jpg) (https://ibb.co/LgYP7SK)
Second, new topload 54 cm outer dia to 62.5 cm outer dia. New resonant freq ~80 khz. My goal is; 800 amps ocd at cm300-12nfh full bridge
(https://i.ibb.co/7Nc3z9F/thumbnail-IMG-1265.jpg) (https://ibb.co/k6nLydF)
(https://i.ibb.co/DpQZYtm/thumbnail-IMG-1262.jpg) (https://ibb.co/TLts1kJ)
Have a nice sunday
Erdal
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What tool/software did you use to calculate your coil inductances and especially coupling factor (from your August 31st 2019 post)? I hadn't found anything available for coupling factor, so wrote my own. Would love to compare its results with known tools.
Thank you!
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Erdal, that is a solid MMC design and snubber capacitors are perfect for MMCs, good that you could find those cheap. There is not a thing to put a finger on :)
New topload dropping Fres to 80kHz, I would say you could push those CM300 to 1kA if you feel adventurous, you even have a little head room for it on the MMC!
Another thing, all your tinypic pictures have stopped working :( You should really upload all your pictures directly on the forum, then it will work "forever" and not loose link to some online 3rd party gallery
Davekni, he simulation you see is from JavaTC, the worlds best online Tesla coil calculator, there is a link to it, among other calculators here: https://highvoltageforum.net/index.php?topic=573.0
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Hi,
I liked my new mmc design too :)) I spent a little more effort on this design. So what have I learned? The most critical part the Tesla coil is mmc (of course the most likely failure and the most spend money)
A little tips, a long screwdriver is perfect breakout point for tesla. No any corona effect for arround surface. sparks only end of the screwdriver. I tried some materials like copper rod, aluminum rod etc. But none of them had a perfectly polished surface, resulting in a corona effect.
I don't intend to make a larger tesla coil. With this coil I can disturb my neighbors long enough :) My goal is to push the limits of this size tesla coil
What tool/software did you use to calculate your coil inductances and especially coupling factor (from your August 31st 2019 post)? I hadn't found anything available for coupling factor, so wrote my own. Would love to compare its results with known tools.
Thank you!
Mads gave the answer in detail with the link. I use javatc online java based calculator. Its great tool for drsstc. I tested that my measurements and calculations give the same value in real
Thnx,
Erdal