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Simple battery charger circuit

Published on Mar 17 2011 // Electrical Circuits

Are generally constant current battery charging method, which can be completed only control the charging time of battery charging. In appearance from the battery, it is the nickel-metal hydride battery, the capacity is 1450 mAh. The standard charging method is: the battery rated capacity of 1 / 10, charging current is 145 mA 14 to 16 hours. The charger charging current of 170 mA measured about charging time is about 12 hours.
Production of the required components are: a transformer, power of 10W or so, the secondary winding voltage between 12 ~ 15V; 7812 a three-terminal regulator ICs; IN4008 diode 4 (or 1A/200V rectifier bridge one) 2200UF/50V electrolytic capacitors and one each in nonpolarized capacitors 0.1UF; a 56 ohm resistor (resistor size can be customized as needed); can put the battery in the battery compartment 4 a; a piece of circuit board, wire number.
Instructions and pay attention to points made: After selecting components assembled in accordance with the schematic circuit, double check to ensure correct welding. Three-terminal voltage regulator integrated circuit heat sink to be installed. Resistance than 2W of power, the best choice flame resistance. Resistor in the circuit board installed in a certain space around him aside because of resistance also have a greater heat. Charging hours: to be filled to capacity 1450/10 * 14 = 2030 mA charge current is 170 mA when charging time is 2030/170 while about 12 hours according to actual needs, you can change the resistor size changes in the charging current within a certain range, it controls the charging time. Under normal circumstances, however recommended not to use high-current charge, so as not to affect battery life.
The charger to the battery to recharge a battery, in my Olympus C-860L can be 200 to 300 pictures (LCD viewfinder screen normally open, and occasionally use the flash), use has been more than 4 months, the battery has been good . The production cost of the charger is only ten dollars, since cost is extremely high, with very satisfactory results.

Simple battery charger circuit 1

 Simple battery charger circuit 2

Description: Printed circuit board J1 connected power transformer secondary output, J2 connected battery pack. Board of D as a rectifier bridge.