RDR-142 Design - 90VAC input problem

Posted by: josehernandez on 10/16/2014

Hello,

I have designed the power supply in the RDR-142 in my system and recently tested it at 90VAC and it will not once fully loaded.

My circuit it is almost an exact copy of the RDR-142 except that it uses the +12VAC output only.

If the supply is loaded at 50% it work but once the load is changed to provide full pwoer then the supply shuts down and it tried to recover.

I really need t ohave this supply work at 90VAC (or down to 87VAC input).

Please help me fix this issue as I have my system down due to this issue.

I am including an exact copy of my circuit.

Comments

Is your transformer design the same as RDR-142?

I recomend the first thing to do is to check the face of the transformer. By what you are telling me, it is a very typical situation when one of the windings is not in the right phse

Hello,

the transformer I am using is the Wurth Electronics 750811630. I am not using the one in the application note.

Perhaps this is part of the problem.

I cannot deliver full power at 90VAC input....the IC will shutdown once the 78% duty cycle is reached.

Any thoughts how to fix this issue..?

Thanks,

Is your transformer designed to deliver the amount of power you need?