| 摘要 |
<P>PROBLEM TO BE SOLVED: To supply a control means with the voltage for operating the control means even if a voltage from a standby power source circuit in a standby condition is equal to or less than the voltage for operating the control means. <P>SOLUTION: This power source circuit 1 includes: a main power source circuit 3 which generates a voltage for operating a microcomputer 5 in a normal operating condition; a standby power source circuit which generates a voltage for operating the microcomputer 5 in a standby condition; a switching circuit 13 which turns the main power source circuit 3 off when turned off and which turns the main power source circuit 3 on when turned on; and a voltage detection circuit 6 which detects whether or not the voltage from the standby power source circuit 2 is not more than a threshold voltage in the standby condition and which if detecting that the voltage from the standby power source circuit 2 is not more than the threshold voltage, controls the switching circuit 13 to turn on, and which if detecting that the voltage from the standby power source circuit 2 is greater than the threshold voltage, controls the switching circuit 13 to turn off. <P>COPYRIGHT: (C)2010,JPO&INPIT |
