Need schematic for PS3003 power supply

[northwest]

I have been searching the internet in vain for a schematic for a HQ brand PS3003U 0-30VDC 3A benchtop power supply. I went 10 pages or more deep into a Google search and cannot find anything. Is this a Chinese State secret or what? This power supply or identical variations are sold everywhere including Velleman and Fryes. I can find the operating manual but not the schematic. It would be good to have in case I ever have to repair mine.

[haklesup]

Despite being able to find schematics for some things like appliances, cars and home entertainment items, the vast majority of hardware schematics will never be posted in the public domain. I suspect this falls in the category. That's not to say its hopeless. PS are usually built on 2 sided PCB making them possible to reverse engineer and if you look for the datasheets for a few of the key IC chips, you just might find an application circuit example in the datasheet that's an almost match to your PS. There's a good chance the circuit is not very novel.

[Janitor Tzap]

Yeah,

I agree with haklesup, in that you should look at the datasheets for a few of the key IC chips.
And any application circuit example in the datasheets that's an almost match to your PS.

But you mentioned power supplies that are identical, or variations on it, being sold by Velleman and Fryes.

I'd get the model numbers off those power supplies, and see if schematics are available for them.
Then see if any of schematics closely matched what your working on.


Signed: Janitor Tzap