Measuring Current With Resistor

@

Thread Starter

@StevenJones

I'm looking to measure current by using a resistor — at 25o ohm — across the negative power supply given to the instrument.
I'm using a 24VDC power supply. I connected the positive voltage directly to the instrument.
 
@

@StevenJones

Here again.

For that instrument, a 24VDC power supply is used. I connected the positive voltage directly to the instrument.

I can measure the current taken by the instrument. It does often malfunction. It will take 4 to 20mA current.
 
The resistor needs to be in series with the supply to measure current and at 20mA a 250ohm resistor is dropping 5V which may be affecting her circuit in use.
 
@

@StevenJones

Negative supply from the 24VDC SMPS is connected to 1st pin(GND) of IP connector. The 2nd pin of the connector is connected to instrument's negative side.
 
@

@StevenJones

It's working fine now.

I can measure the current taken by the instrument. Occasionally, however, it will malfunction and take 4 to 20mA of current.

Thoughts?
 
Top