More beginner questions (digital multimeter)

"AB"

** Set the meter to read DC, if there is no reading the wart is AC or dead.

Set the meter to AC - see which it is.

** No.

....... Phil

I know to start manually on the highest scale and work your way down when using it on unknown voltage etc (or use AUTO scale), but I was wondering about if you wanted to measure the voltage from say, an unknown/unlabeled wall wart. If you don't know if the end voltage is AC or DC how do you proceed?

Can you damage the DMM if you try to measure AC on the DC settings or vice versa?

You CAN measure DC on the AC range. However try a high DC range low enough to get some indication. If the polarity changes when you reverse the probes it's a DC supply.

"Homer J Simpson"

** Only with some DMMs - most have a blocking cap. ** Bollocks.

If you get a reading on the DC range - the wart is DC.

DMMs reject AC signals on their DC volts ranges.

...... Phil

Start with the DMM on high AC volts and get a measurement. If it's reading zero, switch to high DC volts and dance down.

A good DMM won't self-destruct trying to read AC volts on a DC range. Some cheaper DMMs will, though, especially if you put them on DC and try to measure line voltage AC (although the display will be all over the place). For a low voltage wall wart, though, it shouldn't be lethal even for the cheapies.

Good luck Chris