In this space, visitors are invited to post any comments, questions, or skeptical observations about Philo T. Farnsworth's contributions to the field of Nuclear Fusion research.
Subject: Re: Ceramic caps
Date: Oct 29, 3:28 pm
Poster: Richard Hester
On Oct 29, 3:28 pm, Richard Hester wrote:
I would suppose in this case "reasonable" depends on how deep your pockets are. Since the ceramics have been around for a long time, they are not too difficult to find at prices of 0.1-0.5 of list. Large (1500 pF, 40KV) doorknobs can cost upwards of 100 dollars apiece new. I don't doubt at all the the new Maxwell caps are very nice -I grab on to surplus Maxwells whenever I can find them at a reasonble price - but I would expect them to be pricey and not yet available on the surplus market. I would expect pricing comparable to that of new ceramics, or maybe slightly less to "prime the pump".
I'm using ceramics myself in a copper halide laser project with voltage around 10kV, and max rep rate of 10kHz. I was tempted to roll my own capacitor with kapton tape and foil, but the doorknobs make it easier to change capacitance. I'm using 40kV caps, so there is a large derating factor. I hope to be able to report on their reliability some time in the next few months, if you get my meaning....
>I notice from Maxwell's catalog that they have a series of poly dielectric pulse caps designed to replace ceramics in repetitive discharge (flash tubes, lasers, defibrillators) applications. Their MDE series, 1E8 or 1E9 shots life spec, values are in the few to several hundred nF, reasonable voltages. They aren't too huge, and might be reasonably priced.
- Re: Ceramic caps - Jim Lux Oct 29, 6:12 pm