SOrry! I'm the worst poster. It's not my circuit! Just almost as old.
http://www.national.com/an/AN/AN-31.pdf
Look for "Pulse Width Modulator". Probably almost everyone on this site has seen this circuit.
http://www.national.com/an/AN/AN-31.pdf
Look for "Pulse Width Modulator". Probably almost everyone on this site has seen this circuit.