Power unit for device using volatile memory

Abstract

Abstract PURPOSE: To ensure both the display of the stand-by state and the warning display for the voltage lowering of the battery in a simple way, by actuating the common display circuit with the detection output of two comparator circuits. CONSTITUTION: Main power circuit 4 to supply the power to main circuit 3 is installed along with memory power circuit 5 to supply the power to memory circuit 6 containing the volatile memory. Then comparison 24 is given between the output voltage of circuit 4 and that of circuit 5. And in case only the output voltage of circuit 5 exists, the stand-by state is detected. At the same time, the voltage derived from the output voltage of circuit 5 is compared with the voltage of battery 16, and the comparator circuit comprising resistance 26, constant voltage diode 27 and transistor 28 produces the detection output when the voltage of battery 16 lowers less than the prescribed level. Thus, display circuit 29 is actuated by these two comparison output to ensure the common display COPYRIGHT: (C)1979,JPO&Japio

Inventors

• 👤 Yukinori Furuya
• 👤 Hazama Yasue

Bibliographic Details