circuit diagram on line library

[JohnWW]

Hello All

Looking for a online (hoping for free) circuit diagram and schematics library. Mainly looking for something that includes power supplies.

Thanks

   

[wasyoungonce]

Depends upon what you mean power supplies.  In old days we used to use High Country Service Data for TVs, VCRs Microwaves etc.
http://www.hcsd.com.au/

These included full circuit diagrams and was a paid service.   Since the internet...these services are used less and less an some free places have shown up.

But for power supplies...if you mean computer PSUs....then probably not.  mfgrs change design so much they hit the market.   Or try this link in the repair forum:
https://www.eevblog.com/forum/repair/repair-documents-and-links-sticky-me-please-mods/

[JohnWW]

spend a lot of time fixing power supply's for flat panel displays. It there a good online library for that?

Thanks

[wasyoungonce]

Meh....after repairing the first 5~6.... their SMPSs are all the same.

I have found these type of PSUs part number online.   On the PCB will be lots of numbers.  One Sequence or part there of  will probably pop up.    Usually drop the revision number when searching.

edit:
usually PCB number searches brings up other part number references for other models the PSU may fit.   Sometimes a fleabay search for the panelmay give some assistance.

[wasyoungonce]

Forgot Bad Caps Forum...just saw a post on EEVBlog......jogged my memory.  The reason many many SMPSs fail from failing electrolytic capacitors ESR going high.  This has been happening since the advent of SMPSs back in 80's and unfortunately is still in plague proportions.   SMPSs put huge higher frequency ripple load current draw on voltage rails (hot side) and this heats caps which start to wander out of tolerances.

Cold side caps are also prone to fail which folds the SMPS (hot side, via opto couplers)  to shut-down.  You can sometimes hear a "tick" which is the PSU trying to restart then shutting down because cold/hot side feedback is shutting it down....and it continues.

https://www.badcaps.net/forum/index.php