On Wednesday, January 18, 2012 2:55:09 PM UTC-8, Chas wrote:
I plan to use a ''boombox" in my vehicle because the existing sound device
is defective and next to impossible to remove.
My boombox uses 6 AA batteries...would it be safe to just run a plug from
the 12v cig lighter to a power plug on the boombox?

Well, yes there are plugs that would be safe. They're commonly
used for cellphones and such, and they contain a fuse and suitable
stepdown power supply. First, you need the power ratings of
the boombox (probably 9V at 1A will suffice to fill a small car
with tunes), and of the lighter socket.

The car power may have spikes up to 50V, so the conversion does
offer some challenges. If the 'boom box' has AC power option,
an off-the-shelf inverter to make 120VAC will be the easiest option.