DC Meter To Read AC ma: Possible ?

[Robert11]

Hello:

I wish to set the heat-anticipator on a heating thermostat by mesuring the
current flow thru the circuit when energized.

It's probably about 400 or so ma, ac

But, I only have a meter that reads in dc ma.

Any way around this ?

Any conversion factor ?

Or, would it just blow my meter (dial type) ?

Thanks,
B.

 

[Palindr☻me]

Hello:

I wish to set the heat-anticipator on a heating thermostat by mesuring the
current flow thru the circuit when energized.

It's probably about 400 or so ma, ac

But, I only have a meter that reads in dc ma.

Any way around this ?

Any conversion factor ?

Or, would it just blow my meter (dial type) ?

Thanks,
B.

If you have ac volts ranges, you can stick a suitable resistor into
series with the circuit and measure the voltage drop - and use the
resistor value to convert to current. eg a one ohm one watt resistor
will drop 0.4v ac when 400mA ac is flowing through it. A ten ohm
resistor would drop 4v ac under the same circumstances but would need to
be a couple of watts rating or more.

Or you can stick the meter at the centre of a full-wave bridge
rectifier. But you would have to calibrate it, say using fixed resistors
and a known supply voltage. It would be highly non-linear - particularly
at low readings..