| 摘要 |
The method and the device described are intended to avoid the dissipation of electrical energy that occurs in the coil of a stepping motor when the coil is short-circuited permanently between two drive pulses. The method comprises short-circuiting the coil at the end (t1) of the drive pulse, then putting it on open circuit at the instant (t2) when the current (Ic) flowing through it during the short-circuit becomes zero, and short-circuiting the coil again at the instant (t3) when the voltage induced in it by the rotation of the rotor while the coil is on open circuit becomes zero or reaches a predetermined value (Ud). The device is designed to carry out the method. The invention is applicable to the control of stepping motors of the type for instance that are fitted in electronic timepieces having a hand display. |
