SECONDARY CELL CHARGING CONTROL CIRCUIT

摘要

PROBLEM TO BE SOLVED: To realize a secondary cell charging control circuit, capable of freely setting a charging current by the control by a high voltage switch in a battery pack. SOLUTION: A switch circuit 2 is connected to a secondary cell 3 in the battery pack 19. The circuit 2 is connected to the output of an AC-DC converter 1 in an adapter power source 18. The output of a clock signal generator 6 variable at a duty factor by a duty factor variable terminal 4 is connected to the input terminal 16P of a level shifter 16. Thus, a on/off of the switch circuit 2 is controlled by the output signal of the shifter 16. The drain of a high breakdown voltage P-channel MOS transistor 9 of a reset circuit 17 is connected to the drain of an N-channel MOS transistor 11.