Facing a problm with transformer in flyback

Posted by: nagasahitya on 12/10/2012

requirement was o/p 40V to 150V variable with load current 1A and input is 90V DC

we have designed in flyback topology with above requirement based on PI application note AN32. functioning wise design is satisfied, but in running in continous Tranformer is getting more heat. For this we have changed design 4 to 5 times with different tranformer constructions, but still problem was not solved.

so kindly suggest an idea for above problem.

note we have used EE 36*18*11 for 100kHZ frequency and ETD49 for 40kHZ frequency. both having same problem.

Comments

Hi,

Is the design running CCM or DCM mode at full load. INcreasing the wire guage will help to keep the copper loss low.

rgds

my design is running in ccm.we have checked with diff wire gauges.but still same problem

Hi,

What is the temperature rise for the transformer at ambient temperature?

rgds

temperature raise at core and coil with respect to room temperature is 60 degree centigrade

Hi,

Absolute temperature of 85 degree C at 25 degree C seems like a resonable design with no air flow.

For example please review http://www.powerint.com/sites/default/files/PDFFiles/rdr142.pdf reference design.

What is the max transformer temperature you want to achieve?

rgds..