Electronics > Beginners
Not sure if i broke a power supply just now
<< < (3/3)
Mp3:
I'm bewildered!
I just got the new power supply in the mail. First thing i did out of the box, switch the multimeter to continuity and there is continuity on Ground and +5V on this one too!!
plurn:
Is this continuity measured when wired up and mains power applied? Or when with no mains connected.

Despite the continuity measurement, did you try to measure voltage on the 5V rail when live?

Just thinking that continuity is measured as a resistance measurement. Resistance is measured I think by applying a voltage and measuring the voltage drop. So you can not measure resistance/continuity properly if the circuit is live.

If by some chance your multimeter is putting out about 5V to measure continuity and it is seeing 5V from the power supply, it might be confused into thinking it is shorted when it could just be that it is being measure incorrectly. Just an idea.



ciccio:
Does the  LED lighs up?
I the + 5V output's voltage correct?

Best regards


janoc:

--- Quote from: Mp3 on June 08, 2019, 05:11:39 pm ---I'm bewildered!
I just got the new power supply in the mail. First thing i did out of the box, switch the multimeter to continuity and there is continuity on Ground and +5V on this one too!!

--- End quote ---

Just a sanity check - you are measuring with the PSU off and between the COM and +5V terminals, right? Not between +5V and the protective earth (market by the ground symbol, third terminal from the left), right?

Because if you are measuring the latter, that could be completely normal, depending on the construction of the supply - this is not a lab supply, it may not be floating and one end of the output could well be tied to the earth pin.

If you are measuring between +5V and COM then make sure the value isn't changing and remains stable during e.g. 10 seconds or longer. Otherwise you are only measuring the output capacitors charging from the meter and the meter will indicate that as a short circuit. That will go away after the caps charge up.
Navigation
Message Index
Previous page
There was an error while thanking
Thanking...

Go to full version
Powered by SMFPacks Advanced Attachments Uploader Mod