| 摘要 |
PROBLEM TO BE SOLVED: To overcome the problem that, since a number of P-type semiconductor FETs having a resistance twice that of N-type semiconductor FETs, are mounted in parallel on the high side as switches for charge-and-discharge control of a battery pack, the cost increases due to increase of printed board area and increase of the number of parts. SOLUTION: A small and inexpensive battery pack can be provided, by comprising a battery 1; a voltage detection means 10 to detect voltage of the battery 1; a current detection means 9 to detect battery current; a control means 5 which receives the output from the voltage detection means 10 and the current detection means 9; and a switching means, which comprises N-type semiconductors to control charge-and-discharge current by receiving the output from the control means 5 located on the high side of charge-and-discharge routes, and is constituted of a FET 2 for charge to control the charge-and- discharge current from the load side, and a FET 3 to control the charge-and- discharge current from the battery side. |
