capacitor banks on mains too?....

hey all, ive just had a random thought in regards to high power use from 13amp sockets.

amps use capacitor banks to provide power for peaks exceeding the PSU's capacity. why not have 240v capacitor banks inbetween wall and amps? would this not provide power for large bass hits etc...? a few farreds of capacitance should suffice, or is the pottential difference of current going to make this too dangerous?


DISCUSS

An amplifier also uses DC power in combination with that capacitor bank.
And what kind of current comes out of your wallsockets? (DC is the wrong answer)

This will not work, or even more specific, it would make things worse!
Capacitors do conduct AC, so they would take some power of off your 13 Amps, leaving less for the amps.
If you would be able to buy capacitors for 250Volts / a few Fahrad's they would probably use more than 13 Amps. Also, they would cost as much as some decent amplifiers.
Not a good idea, i am afraid, lets go over to the next one......
Using more plugs, every 2 amplifiers on a plug forinstance could be something.
If i am correct, you can use 35A. per mains ring? aren't there usually 2 sockets in one housing? I am not 100% familiar with the BS, i live in Holland.

You can get cap banks for 240 VAC.It will not have the same effect on an AC supply as on a DC supply....As carl says it will be a waist of power,and will increase your level of "wattless power"or will have your supply running at a leading powerfactor to word it differently.Because you are dealing with an alternating waveform a capacitor will cause the current wave to lead the voltage wave.....An inductor on an AC supply will cause the very opposite of this effect,current will lag voltage.Either of these conditions will draw more current ontop of your orignal load(ie amp).

This is the basis of powerfactor.A load thats is heavily capactive or heavily inductive is classed as a load of bad powerfactor,or reactive load.If you are using a mains supply your drawn load should be as near perfect powerfactor(pure resistive)as possible.....otherwise you will be using power that is just doing nothing but charging your capactive/inductive load.this power is not doing any work for you hence the term "wattless power".
Reactive loads are measured in volt amps reactive(VAR)
Resistive loads(loads of perfect powerfactor)are measured is volt amps.


Have a search on wikipedia,there are a few good topics on this.Its a complicated subject but very interesting.powerfactor correction is in wide use in heavy industry.Some utilitys companies will use massive VAR banks to correct megawatts worth of reactive power.

excellent replies, thanks! and yes, now i remember the theory and way capacitance works, you are absolutely correct. never mind, passings ideas are always good!

ta, Pat

Yes, mains is AC, 50Hz. To smooth AC the way a capacitor smooths DC you need a 50Hz shunt resonator, basically made by connecting a capacitor and an inductor in parallel across the mains, with the values chosen so they resonate at 50Hz (the inductor will be very big).

This resonator will tend to continue oscillating at 50Hz even when current draw is high enough to pull down the mains voltage. It can store energy and act as a temporary supply, delivering at 50Hz.

The real problem is that there's nothing preventing this thing driving back into the supply - so you'd be smoothing the entire local grid, which might variously confuse your electricity meter/rcd, unexpectedly overload wiring and/or annoy the local electricity company.