What would cause a toroid inductor to burn up

cwilbar

Well-known member
Joined
Sep 8, 2015
Messages
1,209
Reaction score
31
Location
Massachusetts
A PC power supply I was going to use my Optiplex 740 build for my Terminator Salvation was smelling funny, and then *click*, just shut down.

I pulled it apart (it is an Antec). A toroid inductor near the outputs was discolored to a dar gray/purple where I could see it. Once removed one side was burned to bare wire. It has clearly been very hot.

I'm not the original owner of the supply, it is something I got in a bunch of parts for nothing.

But I'm very curious what would cause it to cook like that. Was the power supply simply run beyond rated capacity for too long, or could another bad component be pulling excess power through the inductor ?

The PC ran fine till the power supply said OFF!

I've pulled it out. I could rewind it (for kicks). It has 4 windings. 3 a larger gauge which are all paralleled up, and one of a separate smaller gauge that runs to different pads.

I have enough sacrificial inductors in my electronic parts bin (which includes several PC power supply circuit boards) to put together enough wire to rewind it.... but I'd hate to do it just to have the next one burn up.

I've not seen this before. Bad caps, check, seen plenty.... blown semiconductors.... yup.... burnt inductors.... just this one.
 
Too much current! (not to be a smart#$#) Depending on where it is in the circuit this could be caused by very different things. If it's in series with one of the outputs as part of the output filter then it's likely as you suggested the load current was beyond normal for some period of time.
 
Back
Top Bottom