Goofy question

[Ceilingwalker]

Good day all. I have a goofy question. My DVM has an "a/c amps" and "d/c amps" setting. What is the difference? When I measure current they both render the same results. Thank you.

 

[Reloadron]

This is a little confusing as a DVM is a Digital Volt Meter. I assume you have a DMM (Digital Multi Meter) which has functions for measuring DC (Direct Current) and AC (Alternating Current). You are using the meter to measure current in series with the load correct? What sort of current are you actually measuribng as in AC or DC?

Ron

 

[Ceilingwalker]

You're right, my bad. It is a DMM. I just wanted to know what was the difference between the ac current setting on the meter and the dc current on the meter. I have owned the meter over 6 years and I have always put it on ac amps. I was checking current draw from a power supply and checked the ac side, then the output side, then wondered why I had to change the meter since current is current, right? I understand how ac current is alternating and dc is steady. Thank you for the reply.

 

[crutschow]

Current is not current. You measure AC differently from DC.

The basic meter measures DC (or the average value). If you put try to measure AC with the DC range it typically will measure 0V since the average value of the AC waveform is zero.

To measure AC, a rectifier is used to convert the AC to a DC level. Typically they add a capacitor in series with the rectifier to block any DC but, if not, then the AC range may also measure DC, or AC plus DC if you have AC riding on the DC.

 

[Reloadron]

Read Carl's post as he has it covered for you.

Ron