| 摘要 |
PURPOSE:To miniaturize a volume of battery for portable clock, by providing a power source voltage processing circuit to be able to exchange the batteries having different electromotive forces. CONSTITUTION:In case a lithium battery having an electromotive force of 3V is used as a battery 30, transistors TR 31 and 32 are rendered conductive whereas a transistor TR 33 is rendered inconductive. As a result, the voltage of the battery is lowered through a voltage reducing circuit 35 to a value of 1.5 volts, which is used as a power source of a clock circuit 36. In case the silver battery is used as the battery 30 having a voltage of 1.5 volts, on the other hand, TRs 31 and 32 are rendered inconductive whereas the TR 33 is rendered conductive so that the power of the battery 30 is directly supplied to the circuit 36. |
