| 摘要 |
PURPOSE:To prevent an accident such as abnormal temperature increase of a stepping motor from occurring by converting supply power to a voltage and monitoring it and then turning off switching elements when the abnormality is detected and then breaking the supply power. CONSTITUTION:When rotating a stepping motor 1, *Hold signal is set to H level and a switching element 2 is turned on and then +VM voltage (+28V) of power supply is applied to each coil winding of the stepping motor l. On the other hand, when stopping and then retaining the stepping motor 1, *Hold signal is set to L level and the switching element 2 is turned off and +5V voltage is applied to each coil winding of the stepping motor 1 via a current- limiting resistor 4. Then, the application voltage to the stepping motor 1 is detected by voltage-dividing resistors 5 and 6 and is inputted to a microcomputer 7 and then phase excitation switch elements 8, 9, 10, and 11 are all turned off when an abnormal voltage is detected. |
