| 摘要 |
PROBLEM TO BE SOLVED: To prevent a stepping motor from becoming a non-rotating state even when its driving margin is varied by its variations, etc. SOLUTION: A pulse-down counter circuit 103 outputs a pulse-down controlling signal DOWN for subjecting a main driving pulse P1 to a pulse-down control when clocking a predetermined time. When a detecting signal exceeding a reference threshold voltage Vcomp detected by a rotation detecting circuit 109 is detected in an initial first detecting interval T1 of a rotation detecting period time, a controlling circuit 104 resets the pulse-down counter circuit 103. Thereby, the unnecessary pulse-down of the main driving pulse P1 is prevented because a main-driving-pulse generating circuit 105 is not subjected to the pulse-down control by the pulse-down counter circuit 103. COPYRIGHT: (C)2010,JPO&INPIT |
