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Re: Coil problem
Tesla List wrote:
>
> Subscriber: FutureT-at-aol-dot-com Thu Jan 2 23:14:15 1997
> Date: Thu, 2 Jan 1997 20:35:05 -0500
> From: FutureT-at-aol-dot-com
> To: tesla-at-pupman-dot-com
> Subject: Re: Coil problem
>
> In a message dated 97-01-02 05:33:34 EST, you write:
>
> << snip
> >These PFC's will need to be 400+ VAC plastic film type - NOT the
> >electrolytic motor starting type. These type of caps can often be found
> > in surplus stores or at Ham Fests. You'll need about 35-40 uF for every
> >15 KV 30 MA neon you use. Four neons would require a bank of about 140 -
> > 160 uF.
> >
> Safe coilin' to you, and happy New Year!
>
> -- Bert --
> >>
> I've been using motor starter capacitors for PFC on my neons, why are these
> caps undesirable; danger of shorting out and/or blowing up?
>
> Happy coiling,
>
> John Freau
John,
Motor starting caps tend to be rather inexpensively made, planned for
only intermittent usage, have higher Equivalent Series Resistance, and
generally tend not to be nearly as "robust" as film caps made for
continuous duty (and generally higher voltage). If you run motor
starting caps for relatively brief times during coiling, they may work
OK. But if you can get better ones cheaply, its probably wise to do so.
BTW, have you noticed any heating or cap failures when using these as
PFC's? Since I've not to used them (for the above reasons), I don't have
any run-time experience with them.
-- Bert --