DC Component measuring

[Kiril Kirilov]

Does anybody have an idea, how can be measured DC component in primary winding of PSU transformer? I hope it's possible without expensive equipment?

 

[dhaen]

Kiril,

Check out this thread:

http://www.diyaudio.com/forums/showthread.php?s=&threadid=9516&highlight=mains+component

With a bridge rectifier and capacitor in one side of the mains supply only, you should be able to measure any DC present across the electrolytic capacitor

Cheers,

 

[stefan]

How do you think?
Will this be good?
If you measure positive and negative voltage across resistors difference between them will (may be) equal to DC voltage in AC outlet.

 

[peranders]

I think you guys have misunderstood the question.

The question is how do I measure the DC part in the AC signal? My suggestion is simply to switch the DVM to DC but some (all?) may have some voltage limiting so the reading MAY be wrong. One trick to avoid this is to attach an external LP-filter, 100k plus 1 µF as a start. This filter reduces the AC part of the signal you want to measure.