| 摘要 |
PROBLEM TO BE SOLVED: To protect overheating by stopping power feed when the period interval of a drive pulse reaches fixed time or longer when a stepping motor is driven. SOLUTION: A drive pulse circuit 4 does not generate output when a stepping motor drive circuit 3 receives a pulse from a control circuit 1, starts supplying a drive pulse to a stepping motor 6, at the same time a drive pulse is received, and a period interval is a pulse within time determined by a time constant that a drive pulse-monitoring circuit 4 has. Then, when the period interval of the drive pulse reaches a time constant or longer, or when the drive pulse stops while a power feed circuit 5 is closed, output is automatically generated as soon as the period interval of the drive pulse exceeds the time constant for controlling the power feed circuit 5, a circuit is opened to stop the supply of power from the stepping motor drive circuit 3 to the stepping motor 6, thus preventing the stepping motor from overheating. |
