PLC810 cannot take loads?

4 posts / 0 new

Based on RDR-189 design sample(PLC810 and TNY275), I made a AC/DC moudle to get a 27VDC power.

If without load, it can be power on and its output was normal(26.8-27.2V). Then I can add loads on it(from 1-8A) and its output voltage was steady, just a little dropped(from 27.0V down 26.2V).

But when I connected a load(resistance load) first, current just 1A-3A, then switched on the power, the output dropped too much, it may be only 4-6V something like that. Also I can hear a high HZ noise from the PCB board, not sure where it came from.

What is the problem? Please help.

Thanks

Jime

Pls. post the transformer design, schematic, spreadsheet, and PCB layout.

PI- Tucker

Did you have a look my schematic drawings & Transformer data? Any problem in it?
Thanks

There is no attachment...