发明授权
US4217751A Electronic timepiece 失效
电子钟表

Electronic timepiece
摘要:
In an electronic timepiece having a stepping motor, a drive pulse is produced for normally driving the motor, a detecting pulse is generated for detecting whether the motor has rotated in response to the last drive pulse and a correction pulse is produced for driving the motor when non-rotation has been detected. A current limiting resistor is disposed in series with the motor for limiting the current thereto and a switching transistor is connected across the current limiting resistor to short circuit same to effect an increase in the current to the motor. During the detecting pulse, the voltage across the current limiting resistor is compared to a predetermined value. If the voltage is above the predetermined value, which indicates that the motor has not rotated in response to the last drive pulse, the switching means is actuated to short circuit the current limiting resistor and the correction pulse is applied to the motor during the resulting increased current condition so that the motor will be enabled to rotate even when a higher torque load is applied thereto. In this way, a decreased amount of current is used during the normal torque loading condition on the motor.
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