AC line filter - "Just A Little Beefy'er" - 06/19/01 01:15 AM
Here's one more AC line filter - this one is more selective than the other one.
It has a set bandpass area of +/- 50-60 Hz, but from figuring the Resonant Frequency of the RLC network at the input, it looks like the Fres is somewhere around 100.65 Hz, and the Harmonic drain filter portion at the output might be somewhere around >240 Hz - I'll double check these numbers and repost [unless someone else wants to... hint, hint, hint ...]
Anyhow, this one uses the same consepts as the first one does. The Resistor at the input does a dual purpose thing: Drains the Capacitors and helps drain the "Midrange" frequencies.
BTW: These filters are nearly the same as Passive Crossovers used for Speakers in Audio Systems. Differences are there's normally only one line used when placing any series connected elements [in this case, the Inductors]; also, there's normally no center tapped Capacitor banks [or other type of elements].
Bypassing a speaker lead to ground would be done with a Capacitor of small value [in the 10 pF ranges] connected from each speaker lead to a grounded conductor - which is not an active circuit conductor! only runs from a star grounding point to a speaker. It can be driven to earth ground, or just connected to the enclosure of the power amplifier. All depends on the system, components and the interference.
[This message has been edited by Webmaster (edited 06-18-2001).]