wrote in message
ups.com...
Trevor Smith wrote:
In my car I have a bluetooth phone kit that plugs into an auxiliary
cigar lighter socket that is controlled by the ignition switch, which
means it turns off when you turn the key to the start position. I would
like to put an electrolytic capacitor across the terminals of the
socket to give the phone kit enough juice to keep it powered up during
the time it takes to start the engine but I'm not sure how they are
rated, ie: a high number uF a lower number. I know the current that the
kit draws will be needed to get the right capacitor for the right time
but I haven't checked this yet, and I wouldn't the formula to work it
out any way so I was going to go for the biggest.
Any advice would be appreciated
Regards
Trevor smith

This is not a good idea, as you'd need a capacitor the size of atlantis
....

That reminds me of the power supply I made for my first high level language
computer - a UK101 - a kit that involved soldering hundreds of connections
by hand. I decided I wanted to make the supply really smooth, so I put a
10,000 microfarad capacitor across the outlet. It was big, but it would run
the TTL based computer for several seconds after I disconnected the power.

Colin Bignell