Voltage detector for battery

Abstract

Abstract PURPOSE: To reduce the consumption, by detecting the voltage of battery to protect memory only when the power supply of the electronic devices having volatile memories is turned on, and producing alarm when the voltage is less than a given voltage. CONSTITUTION: In the electronic device including volatile memory 4 powered with external power input AC 100V and powering the memory 4 with the battery 6 incorporated on mains failure, the switching circuit 13 is provided, which inputs the voltage of the battery 6 to the comparator 121 of the comparison circuit 12 when the power input AC 100V is fed to ROM2, CPU1, input and output interface 3 and memory 4. The circuit 13 is provided with the transistor Tr133 inputting the signal from the interface 3 and the relay 134 operated with the operation current of Tr133. The voltage of the battery 6 is fed to the comparator 121 via the contact 134' of the relay 134. Only when the power supply is turned on to the electronic device, the voltage of the battery 6 is compared with a given voltage, and if it is less than the given value, lamp 10 display is made. COPYRIGHT: (C)1979,JPO&Japio

Inventors

• 👤 Shunichi Sakaguchi

Bibliographic Details