Simple Multicell Charger Circuit Diagram
Using this charger, you can safely charge up to two pieces of Ni-Cd cells or Ni-MH cells. The circuit is compact, inexpensive and easy-to-use.The 230V AC mains is down-converted to 12V AC (at 500 mA) by step-down transformer X1, converted into pulsating DC voltage by diodes D1 and D2, and fed to the battery charger terminals via current-limiting resistor R1 and silicon-controlled rectifier SCR1. SCR1 is at the heart of the charger. Normally, it conducts due to the gate biasing voltage available through resistor R2 and diode D3, and the battery is in charging mode, which is indicated by LED1. Resistor R2 limits the charging current to a safe value. Charging current of this circuit is about 250 mA. Simple Multicell Charger Circuit Diagram When the battery reaches full charge, SCR2 conducts to pull down the gate of SCR1. This state is indicated by LED2. Now remove the cells from the charger. Normally, Ni-Cd cell with a rating of 500 mAH will take around 2.5 hours to reach full charge...