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Re: Cap break down voltages
ubject:
Re: Cap break down voltages
Date:
Thu, 3 Apr 1997 18:44:22 -0500 (EST)
From:
richard hull <rhull-at-richmond.infi-dot-net>
To:
Tesla List <tesla-at-pupman-dot-com>
At 11:21 AM 4/3/97 -0600, you wrote:
>Subject:
> Cap break down voltages
> Date:
> Thu, 03 Apr 1997 15:02:20 -0500
> From:
> Julian Green <julian-at-glosilk.demon.co.uk>
> To:
> tesla-at-pupman-dot-com
>References:
> 1
>
>
>I am about to start capacitor building again and want to know a good
>working voltage to choose. I currently have
>3 home made poly/foil caps 0.03uF -at-10KV. These caps have
>40mils of good quality poly between the plates.
>
>Some time ago I remember Richard Hull posting about chemical breakdown
>of the dielectric where voltages exceed 10KV.
>
>If this is the case then I see little point adding to the thickness of
>the poly for a higher voltage rating. I will simply build more of my
>0.03uF 10KV caps and wire them in series.
snip
>
>Julian Green
>
>
This latter idea is best, Julian. At 10KV RMS input to a coil, over
20KV
peak might easily appear across working caps. Even in oil, a small RF
corona can appear at this level and the oil is slowly worked chemically
until it fails in the long run. I set the limit for single unit
homebuilt
caps at an arbitrary 10KV RMS applied. I try to never exceed 8KV on
homemade caps. R. Hull