POWER SOURCE UNIT SWITCHING SERIES STAGES

摘要

PROBLEM TO BE SOLVED: To provide a power source unit switching the stages in series provided with simple switching circuit constitution which prevents generation of a lateral current and an abnormal voltage when connection of batteries are changed from parallel connection to series connection or from series connection to parallel connection, and can restrain cost when the numbers of batteries and steps are increased. SOLUTION: This power source unit uses batteries whose voltages change largely according to the amount of charging and discharging, and is provided with a switching circuit which switches a plurality of batteries C1 to C8 from parallel connection to series connection or from series connection to parallel connection. The switching circuit is provided with thyristors Th1-0 to Th9-1 (or gate turn-off thyristors) and prevents generation of a lateral current and an abnormal voltage. The lateral current flows according to residual voltage difference of each battery when connection of batteries is switched over. The abnormal voltage due to the instantaneous closed loop state or the open state of a circuit which is generated by timing for switching over connection of batteries.