# How to measure AC and DC current?

Discussion in 'General Electronics Discussion' started by wjames811, Feb 2, 2012.

1. ### wjames811

4
0
Feb 1, 2012
Can anyone know how to measure the AC and DC current?

2. ### JMW

90
3
Jan 30, 2012
Two ways

There are a couple of ways the easiest of course is with an ammeter. For AC circuits you can use the clamp type that goes around one of the conductors. Other wise you must open the circuit and place ammeter in series in the circuit.
The latter requires some care of course.
First you must know the voltage, and use appropriate safety considerations.
Second you need to know the approximate current. For example if your circuit draws 100 amps and the meter is rated at 10, large quantities of noxious smoke will egress the meter.
The third way is to calculate it, measure the resistance and voltage and calculate using ohms law. Depending on the circuit you may be able to insert a known resistor, say 10 ohms and 10 watts in series with the cicuit. Measure the voltage drop across the resistor and calculate using ohms law.