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Registered Member #1521
Joined: Thu Jun 05 2008, 10:46AM
Location: Hungary
Posts: 128
I came across these chinese "resonant" capacitors, they look really promising plus the price is ok too. They made them as GTO snubbers, and primary capacitors for induction heaters and tesla coils. I wonder if anyone has any experience with this company or these capacitors? GTO cap HV cap
Registered Member #1321
Joined: Sat Feb 16 2008, 03:22AM
Location:
Posts: 843
It's too bad they're not forthcoming with the specs. It would be nice to know things like peak and rms current capability, dv/dt, inductance, etc. Maybe you could ask the seller for a spec. sheet.
Registered Member #1321
Joined: Sat Feb 16 2008, 03:22AM
Location:
Posts: 843
All it says is "high pulse current, high dv/dt", but it unfortunately doesn't give any numbers, as far as I can see.
Maybe I'm spoiled by looking at published data sheets for CDE capcitors, for example, but I don't know how they can recommend these caps for applications such as induction heaters, and not give any numbers.
Registered Member #205
Joined: Sat Feb 18 2006, 11:59AM
Location: Skørping, Denmark
Posts: 741
Balint,
Back in the day of MMC pionering, we would buy the caps and run them at destructive stress levels, adding caps to a string untill they stopped failing within a reasonable timeframe. I recall making an experiment like this starting with one cap, which lasted 20 sec. Two strings with two caps in series lasted just over 2 minutes, 3 strings with 3 caps in series lasted in excess of 15 minutes. I don´t recall just how long the 4x4 combo lasted, but the 5x5 combo is still in use on a daily basis, more than 10 years after it was put into service.
I do realize that the caps I used (56nF @1600V) were cheaper and better suited sizewise for an experiment like this, but just want to point out that it can be satisfying to take the lead, create news and publish them.
Registered Member #135
Joined: Sat Feb 11 2006, 12:06AM
Location: Anywhere is fine
Posts: 1735
HEHEHEH..
The whole construction of this thing is flammable and will produce nasty black smoke from the resin burning when it fails, they should be spectacular when they go!
I like the real doorknobs, haven't had one fail yet. Why pay for an experiment and have to buy capacitors twice, when you can spend once and get caps that are indestructible?
Registered Member #1521
Joined: Thu Jun 05 2008, 10:46AM
Location: Hungary
Posts: 128
I use ceramic doorknob capacitors (2,2nF 20kVAC) on my small NST powered TC, but they aren't the best on higher currents. Right now my 4MOT coil runs with 64 aerovox snubber capacitor (2uF 1kVDC), but I really don't like these long strings of capacitors which are not really avaiable here. I looked after cheap and avaiable capacitors, and found these bigger snubbers, which are ideal for TCs, and you don't need a half ton of them. I don't have money to burn 40$ capacitors, but I do want to buy some for my 2MOT coil. Right now it runs on homemade PP plate/silicone oil filled cap.
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Chinese "resonant capacitors"
