wall transformer for project power supply

Step 6 Test the leads

Plug it in
Put the multimeter on the appriate setting for the value you think it is.
Put the clips on the meter.
Check the meter's reading.
If you pay attention to the negative symbol, you can see what the polarity of the wires is.
Label the leads with masking tape, especially if you don't have different colored boots.

Comments

[jeepmarine]

How do you use a multi meter to determine polarity?

[connors934]

Your meter will have two probes, black and red. The black should be in the COM port. on mine, the red is in a port labeled V/Ohm/mA. When you put the two probes on a battery or DC power transformer, you will get either a positive number or a negative number. If the number is positive and the probes are in the correct holes, then the one touching the red is positive and the one touching the black is negative. Try it out with a battery, which will have markings for polarity until you get the hang of it. Enjoy!

[jeepmarine]

thanks!