Adding large caps?

You don't want to bypass your AC line to neutral with large capacitors. It sounds to me like you are thinking of applying the bypassing used in a DC supply to the AC mains--totally different things.

Sometimes one bypasses line-neutral, line-ground, neutral-ground but only with capacitors chosen for higher frequencies. That is, we might want to remove noise at 100kHz-5MHz and leave the fundemental (50/60/400Hz) relatively untouched.

Another thing that is possible is AC coupling the mains line. This is usually done for a specific purpose, e.g. eliminate DC on mains from causing transformer problems. It needs to be done very carefully.
 
Rino odorico said:
Anyone ever make a "cap bank" to add to the AC line before your gear? What I meen is add this "bank" in-line of the AC...wall outlet--"bank"-- audio gear.

Just wondering if this could/would help anything...and how much is enough?


Rino Odorico

Be aware that any cap that is wired across the AC mains has to be non-polarized and should also be rated for such use. If you put a computer grade electrolytic on your AC power it will self destruct quite violently.

There is little reason to do this anyway. An effective RFI filter on the input to your power supply is what you need. Unless you are building a monster class A amp, your not going to be loading down the AC lines anyways.

Remember power = Volts time Amps. At 12V you've got to push a lot of amps to get power. At 120V you only have to push 1/10 the amps, so voltage drops in the cable are greatly reduced.

Phil