| 摘要 |
PURPOSE: To avoid high power scattering of a conventional stepping motor and a related low efficiency by providing a high-voltage power supply, for excessively exciting the stepping motor, a low-voltage power supply, and an excessive excitation switch mechanism that is connected between a high-voltage power supply means and the input of the stepping motor. CONSTITUTION: A high-voltage drive circuit detects a current by a resistor 18. A transistor(Tr) 13, an output Tr 19, and resistors 16 and 17 constitute a combination of high-voltage switches. When the Tr is turned off, the output of a comparator 28 becomes high constantly, and the high output is inputted to a set pin 24 of an FF 21 via a resistor voltage-divider network. Then, the Q output of the FF 21 turns off the output Tr 19 and then turns off the Tr 13. The output of the comparator 28 becomes high again, a high-voltage power supply is separated from a stepper motor 10, and a low-voltage power supply drives a stepper motor 10 at a nominal level. |
