To: tesla@pupman.com From: Terry Fritz Subject: Cheap 20nF 20kV pulse caps - If it would work?? Cc: Bcc: X-Attachments: In-Reply-To: References: Hi All, I was reading through my catalog looking at caps and a thought occurred to me. I would like to know if this would work. I can get 630WVDC 0.10uF polypropylene film capacitors for $0.43 each. They are designed for current pulse, high frequency, low inductance applications although not quite what we have in mind ;-) They are Panasonic ECQP6104JU types. They are about 1 x 1 x 0.5 inch in size. What I had in mind is this. If I string 8 parallel rows of 40 caps in series (320 caps) I would get one large cap rated at 25kVDC (18kVAC) at a value of 20nF. It would cost $138 plus a container, oil, and a bunch of 1M ohm balance resistors (I could put 40 transorbs in also to protect the caps for not too much more money). Perhaps it would be ok left in free air?? It wouldn't have the 3X rating we like but these are commercial caps with the usual 5 seconds at 250% over voltage rating. Each string may see around 30 amps peak during a firing pulse. It would be interesting in that each cap or string could be easily replaced if something blew. Obviously this would be a good deal and the source of the caps is practically unlimited. IF, of course, it would work?? Comment are requested (on or off list) before I try it. I don't want to blow a couple hundred bucks in this experiment to find I missed some obvious problem. Thanks, Terry terryf@verinet.com