Cobble together a DC current meter?

[circus]

Can measure volts, ac current and ohms but not dc current. Is there something I can cobble together? Nothing elaborate. Don't want to steal the one out of the old fashion gauge cluster. Don't want to buy another clamp meter just for a couple minutes use.

 

[Hedges]

Voltage drop across a known resistance, could be a length of wire.
Trouble is how you measure low ohms. If you have a power supply that can put out regulated (or measured) amps, you can put that through your "shunt" and determine its resistance.
Use a 4-wire configuration, current connected with two contacts, measure voltage with two other contacts.

You can look up resistance per foot of 12 awg or the like, use that.

 

[mikefitz]

If the current range is amps to 10s of amps a length of stainless steel studding, say 1/4, cable connected by back to back nuts, a length around 3 inches to start with, meter on lowest mv range. 12v car battery and headlamp bulb gives 4 amps.

Mike

 

[circus]

Now I feel silly. Turns out my $4 multi-meter can measure <10amp. Might buy one of those hall effect or shunt gauges for >10amps. Not as convenient as a $$$ clamp style but good enough for as often as I'll use it. Thanks all.

 

[efficientPV]

Those small meters can, but often their connectors and leads can't.

 

[HRTKD]

Years ago, at a flea market I bought a tackle box full of tools and air hose supplies. Buried in the bottom was this little gem. It's not digital, it's not precise, but it works.

 

[circus]

It's not digital, it's not precise, but it works.

Yea, got those on my old stuff along with oil pressure and temperature. Tried out my new powers. Measured an inverted 120v 60w equivalent led vs a 12v 60w equivalent led (expensive little turd). The 12v only saved me 2 watts but worth it not hearing the cheap inverter fan.