[R-390] Power line Filter

[Bill Hawkins]

Roger,

You're one of the best on the list, so I hate to even mention this.

Capacitors to not pull real power. If they did, they'd heat up.
Instead, they draw reactive power which doesn't show up on a watt
meter. Think of them as tiny power factor correction caps.

The GFI doesn't know that the current is out of phase with the
line voltage, and neither does your body when you put yourself
in the current path. Your wattmeter does know that the reactive
current is out of phase, so it doesn't show cap current times
line volts.

Years ago, when 2 mfd 600 V bathtub caps were cheap, you could
use one to light a pilot lamp from 120 VAC without the heat of a
dropping resistor. The lamps didn't last long if they were turned
on and off frequently, due to the initial charging current if the
switch closed at the peak of a line cycle. Never tried a small 
series R to drop the surge current, though.

Bill Hawkins
 

-----Original Message-----
From: Flowertime01 at wmconnect.com
Sent: Thursday, October 21, 2010 6:06 PM
To: r-390 at mailman.qth.net
Subject: Re: [R-390] Power line Filter

Do your 
homework and consider the caps in question are pulling power even when the 
receiver is off.