Step motor control mechanism for electronic timepiece

Claim 1

An electronic timepiece having a step motor and comprising a quartz crystal vibrator producing a high frequency time standard signal, divider circuit means for producing low frequency time signals in response to said high frequency time standard signal; a gear train driven by said step motor and adapted to place the step motor in one of a first normally loaded condition and a second loaded condition; load detection means for producing a load detection signal in response to detecting said second loaded condition of said step motor; driving and control means intermediate said divider circuit means and said step motor for receiving the low frequency signal from the dividing circuit means, said driving and control means being adapted to apply a first drive signal having a first pulse width to said step motor in response to said low frequency signal, said driving and control means in response to said load detection signal being applied thereto, being adapted to apply to said step motor a second drive signal having a pulse width of longer duration than said first pulse width, said step motor including a drive coil for receiving said first drive signal produced by said driving and control means, said load detecting means being adapted to detect the induced current in said drive coil in response to said first drive signal being applied thereto, said driving and control means including timer means, said timer means being adapted to select a predetermined time interval, said driving and control means being adapted to apply said pulse width of longer duration of said second drive signal to said drive coil during said predetermined time interval selected by said timer means.