CIRCUIT FOR PREVENTING DISCHARGE AT POWER SUSPENSION TIME OF A CHARGEABLE POWER SOURCE

PURPOSE:To prevent the discharge of a storage battery by making a switching element OFF during the suspension time of a power source at a voltage value wherein an output voltage of a detector is divided by a resistor connected to the output terminal and by a resistor connected to the voltage detector of a storage battery. CONSTITUTION:A resistor R2 is connected to an output terminal of a charging apparatus A which outputs DC voltage which is stepped down from AC 100V by a transformer 1 and rectified by a diode D0. A storage battery 2 is charged by a DC through a diode D1, while, a DC is applied to a switching element 4. A terminal voltage of the storage battery 2 is detected by a voltage detector 3, a switching circuit 4 is made ON via resistor R1 and a load circuit, e.g. transceiver 5 of a handset part B of a cordless telephone set, it supplied with the produced DC. When an AC is suspended, the resistors R1 and R2 make continuity in series via diode D2, and the voltage divided by the resistors R1 and R2 is applied on the switching circuit 4 and said circuit 4 is turned OFF before the voltage of the battery 2 becomes over-discharged state. By this structure, when the AC supply is restored, the telephone conversation is immediately resumed.