An FET full bridge switcher for inductorless capacitor charging for Nova

Switching power supplies were designed for the Nova 10 mm rod amplifiers. A simmer supply keeps the lamp turned on continuously by providing 70-110 milliamperes of dc current while a flashlamp supply repeatedly charges and regulates a capacitor before its energy is dumped into the lamp. The chief difference in these two supplies is their output transformer. A full bridge configuration using power mosfet's is simple to drive. The transformer is designed to provide adequate inductance to limit rate of rise of charging current to an acceptable level. Fast recovery diodes in the bridge provide excellent FET turn off characteristics, eliminate ringing through the transistors, and provide a path for transformer energy to be transferred to the load at the end of each cycle