Electric Flight in Australia


Do I need a digital multi-meter?

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A multi-meter is an essential tool for an electric flier. It is used to check the voltage of ni-cad packs, to check the pack cell by cell to detect a faulty one, to monitor voltage peak during charging, to check circuits, to check that current is getting through switches, to measure voltage drop and to measure current draw. I used an analogue meter for ages before trying a digital type, and I don’t know why I didn’t try it sooner. I can now, in all conscience, highly recommend that all serious electric fliers obtain a good digital multi-meter.

Features to look for when shopping for a digital mutli-meter are DC volts range (usually this is more than adequate), milli-ohm range, and DC current range. Most good meters will meaure up to 10A or 20A DC. You can shunt your digital multi-meter to measure bulk amps, but this is only feasible for use with brushed motors as the shunted meter has to be inserted in the positive line. This does not work, and should not be tried with brushless motors.

Click here to see an article by Phil Connolly on how to shunt a meter.

Click here to see how to use an amp clamp for measuring current with all types of motors - particularly useful for brushless motors.