"Jed" wrote in message
. 125.201...
Hello All!

I recently was looking at a power converter as a possible problem with a
flatpanel monitor.

When I placed a VOM on a 12VDC ac/dc power converter I measured 14 or
better
volts. I was hoping someone in here could tell me if this is normal, and
if
it is safe with a device that specifies 12V for power input.

I measured several other 12VDC power converters and received higher than
the
listed output by 50% in one case (18VDC). It would seem to me that this
would damage a device. Obviously I'm wrong but I would like to understand
why this is.

Any help in understanding this is greatly appreciated!

Sincerely,

Jed

Depends on the device. If it is a big supply rated at several amps or more
and is to run equipment usually ran in a car the voltage is normally set at
13.8 volts. This is the "standard" voltage of a car charging system with
the motor running.

If it is a wall cube, they are not usually regulated. The volage will be
somewhat higher than 12 volts and drop under load to near 12 volts.
If the supply just has a rectifier and capacitor in it and is unloaded it
will be the roughly 12 volts times about 1.4 (peak part of a 12 volt ac rms
reading). Think that 1.4 is close for the multiplier. This is because the
capacitor will charge near the peak voltage of the sine wave.