| 摘要 |
PROBLEM TO BE SOLVED: To provide electrical equipment capable of increasing reliability from that in the case of automatically conducting the serial connection of a plurality of battery cell sets by mounting a battery unit on the equipment main body.SOLUTION: When the trigger of a tool main body 3 is pulled, a trigger interlock switch 36 is turned on, and a switching element Tr1 for start is turned on. Thus, the voltage of the plus terminal of a first battery cell set 21 is applied via the switching terminal Tr1 for start, a diode D4, a diode D6, a resistance R7 and a resistance R4 to the control terminal of a switching element M4 for interruption, and the switching element M4 for interruption is turned on. Then, currents from the plus terminal of the first battery cell set 21 are allowed to flow to photo-diodes D1 to D3. When the photo-diodes D1 to D3 emit the rays of light, photo-transistors Q1 to Q3 which have received the rays of light are conducted, and inter-cell set switching elements M1 to M3 are turned on, and the serial connection of the first battery cell set 21 to a fourth battery cell set 24 is conducted. |
