| 摘要 |
PROBLEM TO BE SOLVED: To use a small-sized inexpensive switch means by reducing a withstand voltage of the switch means. SOLUTION: Switch means 312 are connected in series to plural switch means 311, and therefore a battery voltage of a prescribed battery block 21 is copied into a capacitor 313. After setting all the switch means 311 and the switch means 312 in the OFF state, switch means 314 are set in the ON state, and when reading a voltage to a degree of maximum DC 400 V of an assembly battery voltage, voltages bisected by parasitic capacities Ca, Cb of the plural switch means 311 and the switch means 312 in the OFF state are applied respectively to the switch means 311 and the switch means 312. |
