On 11/22/21 8:19 AM, Lux, Jim wrote:
> On 11/21/21 2:03 PM, Joshua Thomas wrote:
>> Hi Gary,
>>
>> I was using 3kV Panasonic film capacitors; hereâ??s a link for the actual
>> product:
>> https://www.mouser.com/ProductDetail/Panasonic/ECW-HC3F822J?qs=5PZ87NsE%252BJ%2FduaOvzk%252BWIA%3D%3D
>>
>>
>> I chose these caps (total 1nF per-rail) because I get an RC filter with
>> cutoff of ~318khz with the 500ohm resistors. My coil has a resonant
>> frequency of around this value, so my intuitive thought is that I need to
>> bypass frequencies at or above the coil resonant frequency. The total is
>> 2nF which *is* a significant fraction of my 10nF MMC. Is some assumption
>> here in error?
>
> I don't know that you want to try and design your terry filter to be
> consistent with your resonant frequency.
>
> The goal is more to suppress higher frequency transients. I've see much
> smaller capacitors used for this.
>
> Google "terry filter pupman" and look for hits from 10 years ago.
>
>
Here's a write up on filters
http://www.laushaus.com/tesla/protection.htm
450pF
other writeups I've seen have been around 500pF.