| 摘要 |
PURPOSE:To smoothly remove a main battery by providing first, second bipolar transistors(Tr) having the same polarity and connected at collector terminals (C) to emitter terminals, and connecting the output of a main battery to a C terminal and the partial voltage of the main battery and the output of a backup battery to the base terminals of first, second Trs. CONSTITUTION:The base terminal of a first transistor(Tr) 4 is connected to a connecting part 9 of main cells 1, the collector terminals of Trs 4, 5 are connected, connected to the positive electrode of the cell 11, emitter terminals are connected to each other, and connected to a backup output terminal 7. When the cell 1 is disconnected, a current flows from the cell 11 to the backup terminal with the base and the emitter of the Tr 5 therebetween as a PN junction diode, and the change of the backup voltage due to removal of the cell 1 does not substantially occur. Thus, the voltage switching when the cell 11 is removed can be smoothly conducted. |
