Fast battery charger with mains input transformer - uses double electrolytic capacitor t6o join sec. of input transformer to prim. of output transformer

摘要

The fast battery charger has its a.c. voltage input connected to the prim. winding (A1) of a first transformer (T1) whose sec. winding (B1) is connected via a double electrolytic capacitor (C1) to the prim. winding (B2) of a second transformer (T2) whose own sec. winding (A2) is connected to one diagonal of a full-wave rectifier (D). A second double electrolytic capacitor (C2) is connected across the rectifier bridge's second diagonal, which also forms the d.c. charging output. When the circuit is connected to the a.c. supply, it oscillates and an output voltage is produced that increases when the battery being charged is connected and charges it within 11-120 seconds. The oscillations cause an a.c. voltage of 75V at the sec. of the first transformer and the prim. of the second transformer for a 220V mains supply.