Fusion Message Board

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Subject: Re: DIY HV Pulse Cap?
Date: Nov 02, 00:04 am
Poster: Richard Hester

On Nov 02, 00:04 am, Richard Hester wrote:

Do as you like, but the manufacturers of ceramic high voltage capacitors have opted for lower dielectric constant, less electrostrictive materials, for good reason... Other dielectrics might offer more promise. Check out the Maxwell web site to see what I'm talking about. It's a rough life, being a high voltage pulse capacitor.

Richard Hester
>>High-K ceramics are no good for pulse capacitors >precisely because they are piezoelectric, and >tend to crack or pull their connections loose >under the mechanical stress induced by a fast >discharge.
>> Richard Hester
>Yes, that's the problem. When working with Hi E and Hi Mu ceramics, the engineering is more like that of transducers. Electrode and ceramic thickness depends not only on voltage but acoustic considerations. The capacitor could exhibit 'motional inductance' of hundreds of henries, like quartz crystal for oscillators can!
>Mechanical problems need to be dealt with. But the advantage of working with higher voltage means the size decreases with the square of the voltage increase, and with 1000's of times more permittivity/permiability, power supplies can be shrunk over 4 orders of mangnitude!
>Worth the research & trouble maybe?!?!