Hello,
I have made 12 to 220V 500W SMPS inverter with SG3525 IC and I have little trouble with it. When nothing is connected it draws around 1A, and when I connect 75W light bulb it draws 18.7 from 3s li-po battery which voltage is 11.2V. Which is around 210W, almost 3 times the power of the light bulb. At the output of the ransformer the voltage is rectified with full-bridge rectifier build from ultra fast diodes and it's filtered with 330uF capacitor and the voltage at the output is 310V without load and 300V with load. Can anyone tell me why it draws so much power?