| 摘要 |
<p>PURPOSE: To obtain a circuit used for a device where various kinds of operation states such as frequent power source-on/off and leaving of power source for long term as it is, etc., are considered with min. battery capacitance by supplying required back-up current from a secondary battery when the temp. of a chip such as a CMO memory, etc., as a load is high. CONSTITUTION: A power source device 1, a primary battery 10 and a secondary battery 20 are arranged side by side by the butting on an output-butting diode 32 connected to the power source device 1, the output-butting diode 12 inside the primary battery circuit 10 and the output-butting diode inside the secondary battery circuit 20. At the time of back-up operating, an adjusting diode 14 for adjusting the outputs of the primary battery circuit 10 and the secondary battery circuit 20 so as to operate a secondary battery 21 side first is provided. By the configuration, back-up current required till the chip temp. of the CMOS memory, etc., as the load goes down to be surrounding temp. is supplied from the secondary battery 21 at the time of back-up operating and changeover to the primary battery 11 afterwards is executed by the butting of the diodes 12, 22 and 32.</p> |
