Electronics > Beginners

Linear Power Supply, buzzing. Defective? Repairable?

(1/3) > >>

Rainer Dynszis:
Hi,

I just purchased a GW Instek PSM-3004 for less than half the list price. It is a linear power supply that should be comparatively high quality.

Unfortunately, it emanates a buzzing sound even when outputs are disabled, and under load it gets even louder.

I uploaded a video here: https://sendvid.com/vhfmdsjs

Is this PSU defective? Can anyone guess what might be wrong with it?

Thanks for reading  :)

GerryR:
Probably the power transformer core laminations are loose and are humming to the line frequency.  If that is the cause, it really won't hurt anything; it will just be annoying.  I'm not sure how it is done today, but the laminations, at one time, were varnished when assembled and sometimes they break loose.  It doesn't sound really bad as some that I have heard, and the older you get the less you will be able to hear it.  ::)

Rainer Dynszis:

--- Quote from: GerryR on January 11, 2020, 01:36:21 pm ---Probably the power transformer core laminations are loose and are humming to the line frequency.

--- End quote ---

Oh dear. If your guess is correct, then there's nothing that can be done about it, yes?

GerryR:
Depending on how the transformer is made, you can sometimes wrap the core with electrical tape to keep the laminations from vibrating.  I have seen where some people re-varnish or paint the edges of the core laminations and achieve the same thing.  A coating of epoxy will instaed of varnish / paint would work, as well.

It might be advisable to contact GW Instek and let them know that the transformer is humming (if you determine that is what is actually making the noise), and they might send you a new transformer.  :-//

wraper:

--- Quote from: GerryR on January 11, 2020, 02:40:06 pm ---It might be advisable to contact GW Instek and let them know that the transformer is humming (if you determine that is what is actually making the noise), and they might send you a new transformer.  :-//

--- End quote ---
They won't send you anything. Will suggest to seek help from distributor you bought it from.

Navigation

[0] Message Index

[#] Next page

There was an error while thanking
Thanking...
Go to full version
Powered by SMFPacks Advanced Attachments Uploader Mod