Switched battery charger

The charger is designed to charge NiCd batteries with capacities of 150-4000 mAh. A potential 5 V higher than the nominal voltage of the battery to be charged is derived from an 8-15 V mains adaptor by IC1. The supply voltage is decoupled by C1 and C2. The nominal voltage of the battery to be charged, whether this is 1.5 V or 9 V, has no effect on the circuit. lt is therefore possible to charge T1 series connected batteries, provided that the supply voltage is (n·1.5 + 5) V.