battery and a cap question

[JisforJustin]

OK, here is another question. If a 9v battery is hooked up to a capacitor, in parallel, and after that we break the ground line (ie. stereo jack power switching trick) will the battery be drained from being hooked up to the cap continuously?

[phaeton]

If what you mean is:

1) A battery is connected in parallel to a capacitor, and also connected to the circuit
2) By 'breaking ground' you mean that the battery is disconnected from the circuit, but still to the capacitor

then, no.

The capacitor will charge up to its capacity and stop there.  No more current will be drawn from the battery until the circuit is reconnected (but it will be going through the circuit, not the cap).


Unless you have a defective (leaking) cap, that is.

[JisforJustin]

That is what I meant, thanks.

[phaeton]

For the record, you can also put a bunch of large capacitors (like 1000uF) in parallel, and they will power your circuit for a while after the battery is disconnected

More cap == longer play time.    I once had my Big Hare circuit going full blast for almost 5 minutes with 10 huge caps on it