On Jan 18, 9:43*pm, Rheilly Phoull wrote:
On 1/19/2012 1:08 PM, mike wrote:







On 1/18/2012 2:55 PM, 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? I imagine I will need
some sort of voltage reducer. Anyone got any ideas on how one could build
such a reducer. I am fearing such a device may induce noise.
. . . . .I am of an understanding that 1.5v batterys are acutally
1.2v. Is
this correct? If so, I could run the 12v car voltage to 10 AA batterys
and
then tap off six batterys....
Else, if the AA's are truly 1.5 volts then run the 12v car power to 8
of the
AA's and tap off 6.

Don't do that. It's wrong for a lot of reasons.
You need a regulator.
If you intend building something, make sure you understand this:
http://www.littelfuse.com/data/en/Ap...tes/an9312.pdf

Safest thing is to buy a car adapter.

any help would be greatly appreciated.. . . chas

Umm, looking at the OP's message that might be a tad over the top for
his level ??
Sure there can be lots of transients but I reckon for domestic
applications it's not necessary to go beyond some stiff caps or a
resistor and zener or even a choke where the job is to step down ?


Anything's better than trying to use a battery string as a voltage
regulator. The worst that could happen using your idea is that he
would have to buy a new boom box. Second worst is that he would have
to buy a new three-terminal regulator.