Re: capacitive pole pig ballast

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Crow Leader" <tesla-at-lists.symmetric-dot-net> 

If you have high current rated capacitors, why not use them.

The caps in microwave ovens are not rated in amps of AC current, they don't
need to be. Caps from power factor equipment would be a good choice (large
sizes and current ratings). A bunch of lighting/motor run  caps like from GE
in drawn metal cans might be good too, if used in parallel. I've seen these
used in ferroresonant power conditioners, and the circulating currents in
these are pretty high.

KEN



----- Original Message -----
From: "Tesla list" <tesla-at-pupman-dot-com>
To: <tesla-at-pupman-dot-com>
Sent: Friday, January 09, 2004 8:52 AM
Subject: Re: capacitive pole pig ballast


 > Original poster: Jim Lux <jimlux-at-earthlink-dot-net>
 >
 > At 11:36 AM 1/8/2004 -0700, you wrote:
 > >Original poster: Ed Phillips <evp-at-pacbell-dot-net>
 > >Tesla list wrote:
 > > >
 > > > Original poster: "Mccauley, Daniel H" <daniel.h.mccauley-at-lmco-dot-com>
 > > >
 > > > Forget the capacitors.  If you are looking for a simple, low-cost,
 > > > no-frills 3 kVA ballast, then the
 > > > 500ft roll of 12 AWG wire from Home Depot or similar will do the trick
 > > > every time.
 > > >
 > > > Dan
 > > >
 > > >  > Could someone tell me how many .9uf  MO caps it would take to
 > > >  > ballast a
 > > >  > 10kva 14400v pig for 3 kva
 > > >  >
 > > >  > Thanks
 > > >  > Steve
 > >
 > >         I've never understood "capacitive ballasting".  Resistive or
 > > inductive
 > >yes, but seems to me capacitors in the circuit work in the wrong
 > >direction.
 > >
 > >Ed
 >
 > Well.. all you want is some reactive voltage drop for
 > ballasting.  Traditionally, that's been inductive (for a variety of
 > reasons..), but capacitors should work just fine for the voltage control
 > kind of function.  They're used in some consumer equipment as a
 > inexpensive,high isolation technique to get low voltage at low power from
 > the AC line (X-10 modules are a good example)
 >
 > I don't know that they would work well in situation driving a negative
 > resistance (like an arc).. Would there be some sort of weird effect from
 > the phase being opposite? (leading current instead of lagging...)
 >
 > For welders, you already have to have a transformer, so using inductive
 > ballasting by changing the leakage inductance is a low cost way to do it.
 >
 > Likewise, for fluorescent or gas discharge lamps (Neon Signs?) you already
 > have to have a transformer to get the voltage up to striking potential,
so,
 > again, inductively ballasting by increased leakage inductance is easy.
 >
 >
 >
 >
 >