| 摘要 |
PROBLEM TO BE SOLVED: To obtain a drive circuit for motor which can surely restart a motor, when the power supply voltage to the motor is restored, even when the power supply voltage drops temporarily. SOLUTION: When a microcomputer detects a locked state at a time t2 before a voltage drop occurs, the microcomputer monitors whether a starter signal is turned on within a prescribed period of time T2, after the locked state is detected. When the starter signal was turned on, the microcomputer stores that effect in its internal memory. When a battery voltage becomes a prescribed value V2 or higher at a time t5 and the starter signal is turned off at another time t6 thereafter, the microcomputer discriminates whether the starter signal is turned on within the period of time T2 after the locked state is detected, and when the signal was turned on, restarts an ultrasonic motor. |
