118 W high line input Non-PFC CV/CC Flyback chargers supply

This engineering report describes a 59 V (nominal), 118 W flyback reference design for a power supply operating from 180 VAC to 264 VAC. The power supply output is designed with a constant voltage / constant current characteristic for use in battery charger applications. The charging circuit is optimized for a lead-acid battery. At charging currents below ~0.5 A, the output voltage switches form the 59 V charging voltage to a float voltage of 56 V to maintain battery charge without overcharging. This is a standard feature for chargers intended for lead-acid batteries.

The design is based on the TOP267EG with no PFC input stage. It is designed to operate without a fan, with a thermal switch reducing the current limit at elevated temperature (thermal foldback) to enable continued charging at reduced output current without thermal shutdown.