Re: RF chokes

• To: tesla-at-pupman-dot-com
• Subject: Re: RF chokes
• From: "Ed Phillips" <evp-at-pacbell-dot-net> (by way of Terry Fritz <twftesla-at-uswest-dot-net>)
• Date: Fri, 28 Apr 2000 18:35:35 -0600
• Approved: twftesla-at-uswest-dot-net
• Delivered-To: fixup-tesla-at-pupman-dot-com-at-fixme

Tesla List wrote:
> 
> Original Poster: "Lau, Gary" <Gary.Lau-at-compaq-dot-com>
> 
> The use of chokes in NST protection networks is no longer recommended.
> Chokes tend to ring at some frequency with the same amplitude as the tank
> oscillations that you are trying to filter out.  Instead, use R-C networks,
> which have been described and discussed many times on this List.
> 
> As far as your particular chokes, there are several problems.  The choke
> will develop several tens of kV across it in operation.  The small size of
> your cores (toroids?) will make it difficult to insulate end-to-end.  Also,
> ferrite is not an insulator at the voltages involved, so thick insulation is
> required between the wire and core.  And you are correct about saturation.
> Such a small core will saturate with very little current, the result being
> diminished inductance.
> 
> Regards, Gary Lau
> Waltham, MA USA

	Slight correction.  The core will saturate due to the applied voltage,
and you needn't worry about voltage breakdown to the core.  Go to Amidon
web page for information on calculating flux density as a function of
core area and turns/volt.

Ed

• Prev: frequency
• Next: Re: Microwave Oven Transformers (MOTs)
• Index(es):
  • Main
  • Thread