Print

Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length.

[lakeshore]

Can someone kindly point me in the direction of measuring what amperage my motor would be pulling using a digital multimeter. Connections settings etc in order to get an acurate reading.Saw a great one on utube but cant seem to find it again.

cheers
John.

[malcolmfrary]

First, look at the motor spec to get a rough idea.  This helps figuring which scale to use.
Next, measure its resistance using the ohms scale.  Using ohms law, and your intended battery, work out the nominal theoretical current.  Current (in amps) = volts / resistance (in ohms).  Because a motor is an inductive and varying load, double this figure.  This should roughly agree with the spec figure.
To actually measure the current drawn, connect the meter using the "Com" and "A" meter connections in place of the fuse and switch the meter to a higher current range than the previous calculation indicated.  Some meters have an extra terminal for up to 10A.  Such a measurement only means anything under load.

[red181]

get one of these, plug and play, and dirt cheap,

http://www.4-max.co.uk/wattmeter-budget.htm

will measure amps, watts, volts, I used on in the past, just plug in and leave it there, it will record actauls and peak, very handy for testing amp draw with various props etc

[essex2visuvesi]

get one of these, plug and play, and dirt cheap,

http://www.4-max.co.uk/wattmeter-budget.htm

will measure amps, watts, volts, I used on in the past, just plug in and leave it there, it will record actauls and peak, very handy for testing amp draw with various props etc

I wish I'd seen that earlier this week! 

Jus bought all the parts to make my own thing that does exactly that as I couldnt find a suitable one for sale!