Re: Convert 12-14 vdc to 9 vdc for a device only needing 0.3ma...

On a sunny day (Sun, 28 Dec 2008 00:14:38 -0600) it happened "Default User"
<nospam38925@xxxxxxxxx> wrote in <005bdc57$0$24192$c3e8da3@xxxxxxxxxxxxxxxxx>:

Hi,

I've got a battery box with a 115AH deep cycle battery for power in a
tornado shelter.

I had a thought that it would be nice to mount one of the cheap harbor
freight $2 multimeters to it to monitor the voltage. They usually run on a
9 volt batter and consume a nice and small 0.3ma. What I don't know is if
12-14 volts would fry it or if it would do fine on that. Is there an easy
(read cheap) way to drop the 12-14 volts down to 9 volts without increasing
the power consumption very much?

Thanks,

Alan

You need an isolated supply.
See my solution recently posted here.
.

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