Re: Line filter design? (fwd)

---------- Forwarded message ----------
Date: Mon, 27 Apr 1998 21:29:12 -0600
From: "D.C. Cox" <DR.RESONANCE-at-next-wave-dot-net>
To: Tesla List <tesla-at-pupman-dot-com>
Subject: Re: Line filter design?

to: Steve

Most line filters consist of several cap and inductor sections.  It might
be more cost effective to pick up a surplus line filter from Fair Radio
Sales, Lima, OH, or C&H Sales, Pasadena, CA.  Commercial line filters are
well designed and packed for maximum density thus saving a lot of interior
space in your control panel.  We always use two such commercial filters in
series with varisters between the units and also on the end facing the hv
xmfr (hot to gnd each area).  Past the unit facing the hv xmfr we use some
2 inch dia ferrite toroids with approx 4 turns on each -- use in both hot
and neutral legs (one in each leg).  Also a 2 MFD 440 VAC cap is placed on
the power cord inlet area to absorb line surges and provide energy in high
demand situations.  These combinations of filters don't use much panel
space and offer very effective power line filtering.  Also, the 20 amp
surplus units are cheap -- approx $20 per unit or less.


> From: Tesla List <tesla-at-pupman-dot-com>
> To: 'Tesla List' <tesla-at-pupman-dot-com>
> Subject: Line filter design?
> Date: Monday, April 27, 1998 7:42 AM
> ----------
> From:  Steve Falco [SMTP:sfalco-at-worldnet.att-dot-net]
> Sent:  Monday, April 27, 1998 6:37 AM
> To:  tesla-at-pupman-dot-com
> Subject:  Line filter design?
> I'd like to build a line filter.  I understand the basic schematic is
> inductors in series and capacitors to ground, perhaps with MOVs across
> the capacitors, but does anyone have a specific design?  I'd like to
> know the values of the caps and MOVs, as well as how many sections are
> needed.
> I have some 2" ferrite cores, and I'd also like to know how many turns
> of wire might be needed for a line filter.  I assume this is different
> than when building a protection circuit for a neon.
> 	Thanks,
> 	Steve Falco