Hi,
I have this circuit charging a 8xAA battery pack.
http://www.members.dca.net/kben/misc/buck.html
I am also using a 500Hz PWM, not 100Khz.
The fet and coil specs are slightly different, but the closest
I could find from Digikey. My Vin is coming from a 20Vac 800ma
wall wart, going through a full bridge rectifier. I am able to
control the charging current OK with the PWM from my PIC.
The charger has 3 modes full 1000ma, soft 375ma,
and trickle 75ma.  The problem is on my first full test,
the wall wart got very hot after about 35 minutes of
FULL charging.  Can someone enlighten me as to why it is heating
up ?
Thanks,
Kevin

P.S. I am a programmer not an EE.

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