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12VDC/300mA transformerless power supply design

Posted by: zameer on

Hello

I am trying to make a design of 12V/300mA curcuit.
Reference for design was taken by file downloaded from your site. FIle name is rdr131.pdf.
First curcuit I had design was working fine. This design was same as fig 3a and fig 3b in file rdr131.pdf
After getting one working curcuit, I made a PDB and now after mounting, I found that same curcuit shows give output as 316VDC with 230VAC.
This behaviour is very strange, I had checked complete curcuit and all the component, there is no error in PCB and component as per design.

Also for your information, I get 316VDC as output on board, only when I mount LNK306PN on board. Otherwise everything seems to be normal.
I dont understand this behaviour.

Summary, my aim is to make 12VDC.300mA transformerless power supply curcuit.
So I will be very thankful to the one, who could give me the solution.

As this is very urgent, so fast response will be appriciated.

Thanks and Regards,
Shaheed Chaudahry
9373949388
SChaudhary@lear.com

Files

Attachment Size
rdr131.pdf 459.05 KB

Comments

Submitted by Tim Starr on 04/07/2009

It sounds like there must be some sort of error or short in your PCB. 230 VAC is about 325 VDC so it sounds like your output is shorted to your input.

If possible attach an image of your EXACT schematic and layout to this post and I will check that they are correct.

Hope to hear back soon. Thanks!

PI-Wesley

Submitted by Tim Starr on 04/07/2009

It sounds like there must be some sort of error or short in your PCB. 230 VAC is about 325 VDC so it sounds like your output is shorted to your input.

If possible attach an image of your EXACT schematic and layout to this post and I will check that they are correct.

Hope to hear back soon. Thanks!

PI-Wesley