| 摘要 |
PROBLEM TO BE SOLVED: To provide a motor revolution detecting device which can accurately detect a revolution, both in a low-revolution range and in a high-revolution range. SOLUTION: If a rotor revolution ωn-1 previously calculated is not higher than a prescribed value, a microcomputer 6 makes a switch means 4 select the microcomputer 6 and calculates a present motor revolution ωn by using a period T between pulse edges of pulse signals S3 transmitted from an edge detector 3. If the rotor revolution ωn-1 previously calculated is higher than the prescribed value, the microcomputer 6 makes the switch means 4 select a counter 5 and calculates the present rotor revolution ωn by using the number N of pulse edges of the pulse signals S3 within a prescribed period T0. |
