| 摘要 |
PURPOSE:To reset a microprocessor for radio equipment control in unstable periods such as the rising and falling of a power source voltage by detecting the operation of a power source switch before the voltage of a battery power source mounted on a motorcar is supplied to the microprocessor. CONSTITUTION:Once the power source switch 1 is turned on, a switch detector 2 detects its rising, its one detection signal is delayed by a delay circuit 12, and a relay driver 3 is operated to close a contact 5 to supply the power voltage from the battery power source to regulators 6a and 6b. The other detection signal is supplied to a restarting circuit 7A to output a reset signal, which is supplied to the CPU8 of the microprocessor 10 and a logical gate 13 for turning on and off transmission; the CPU8 is placed in reset operation for an unstable period of the power voltage and the processor 10 inhibits uncertain operation to disallow the transmission driving circuit 11 of radio equipment to operated. When the power switch 1 is turned on, unsecure operation is inhibited. |
