These days many of electrical appliances (watch, RC car, radio etc) use Ni-Cd battery. Here is a simple circuit of Ni-Cd battery charger in the series of easy electronics projects.
Circuit Description and working principle of Ni-Cd Battery Charger
Basically Circuit of Ni-Cd battery charger is rectifier. The input from AC mains is directly given to the circuit through resistors R1 and R2, where resistor R1 is used to limit the surge current and resistor R2 with capacitor C1 is used to limit the leakage charge current. The output from these resistors is rectified by bridge rectifier build using diode D1 through D4.
The output from rectifier is given to the battery charging. Three 1.5V Ni-Cd batteries are connected in series for charging. It took around 20 hour to charge 3*1.5V Ni-Cd battery.
PARTS LIST OF Ni-Cd BATTERY CHARGER
|Resistor (all ¼-watt, ± 5% Carbon)|
|R1 = 150Ω/1W|
R2 = 470 KΩ/1W
|C1 = 0.22 µF/400V|
|D1 – D4 = 1N4007|