| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a simple constant voltage power supply circuit for a microprocessor including a standby open-circuit switch. <P>SOLUTION: A fourth constant voltage power supply circuit 40D to which electric power is directly supplied from an on-vehicle battery 101 is parallel-connected through a series resistor 41 to a second constant voltage power supply circuit 20S to which electric power is supplied from the on-vehicle battery 101 through an output contact 102a of a power supply relay and is connected to a driving power supply terminal of a microprocessor 120A. When the output contact 102a is closed, the microprocessor 120A is operated by output voltage from the second constant voltage power supply circuit 20S and an output current from the forth constant voltage power supply circuit 40D is restricted to a predetermined value or less by the series resistor 41. In operation stop that a power supply switch 103 is opened, a fine standby current is supplied from the fourth constant voltage power supply circuit 40D to the microprocessor 120A. <P>COPYRIGHT: (C)2013,JPO&INPIT |
