초록 ▼

In an electronic timepiece having a stepping motor which drives time indicating means, a system is provided for detecting an increase in the load torque on the stepping motor above a predetermined level. When such an increase is detected, the conditions for detection of the load on the stepping moto

In an electronic timepiece having a stepping motor which drives time indicating means, a system is provided for detecting an increase in the load torque on the stepping motor above a predetermined level. When such an increase is detected, the conditions for detection of the load on the stepping motor are changed, and thereafter drive pulses of increased power are applied to the stepping motor. When the increased load is removed, this is detected under the new set of detection conditions, and a return to the original detection conditions is executed, with the drive pulse power being returned to the original level. Stability of control is thereby provided, together with immediate response to increased load on the stepping motor.

대표청구항 ▼

An electronic timepiece powered by a battery, comprising, in combination: a source of a standard frequency signal; a frequency divider circuit responsive to said standard frequency signal for producing a unit time signal comprising a train of pulses; waveform converter means responsive to said unit

An electronic timepiece powered by a battery, comprising, in combination: a source of a standard frequency signal; a frequency divider circuit responsive to said standard frequency signal for producing a unit time signal comprising a train of pulses; waveform converter means responsive to said unit time signal in conjunction with a relatively high frequency signal produced by said frequency divider circuit for producing a drive input signal; a drive circuit responsive to said drive input signal for producing a drive signal; a stepping motor having a drive coil coupled to receive said drive signal, and periodically actuated by said drive signal to rotate a rotor thereof through a predetermined angle; time indicating means driven by said stepping motor for indicating time information; a sampling signal generating circuit for generating sampling signal pulses of a different phase in dependence on a state of said stepping motor; and a detection circuit having input terminals coupled across said stepping motor drive coil and responsive to said sampling signal pulses for detecting the amplitude of a voltage developed across said drive coil during a sampling interval and producing a status control signal at first and second logic levels in dependence on said detected drive coil voltage; said waveform converter means including means responsive to said first logic level of the status control signal for producing a first drive input signal to cause said drive circuit to drive said stepping motor in a first operating state, and responsive to said second logic level of the status control signal for producing a second drive input signal to cause said drive circuit to drive said stepping motor in a second operating state.