Multifunction DAQ

cancel
Showing results for 
Search instead for 
Did you mean: 

Current Sense Resistor

I'm setting up a measurement channel with the channel wizard in the Measurment and Automation explorer. I'm asked to enter a value for a current limiting resistor. I try to enter the value for my resistor, which is a 0.1 Ohm, 3 watt resistor. The input seems to accept on integer resistor values.

Why 0.1 Ohm? I'm trying to measure motor current and the motor has a very low impedance.
0 Kudos
Message 1 of 2
(2,564 Views)
I think that part of MAX is only for a specific DAQ card with built-in resistors, it will not work for you.
You are using a 0.1 ohm resistor to cause a small voltage drop in the circuit across the resistor, the smaller the resistor the less effect on the circuit.

Remember that V=IR, so to find the current, setup the channel in MAX as a voltage channel, then take the voltage and divide it by 0.1 ohms to find the current (V/R = I)

dhuff
0 Kudos
Message 2 of 2
(2,564 Views)