Electric clock with HF time standard cct. - has means for converting oscillator frequencies to motor operating frequency

摘要

The clock has a time standard circuit employing two oscillators, both of the high frequency oscillation type, with the oscillation frequencies of the two oscillators varying by a small amount. The oscillator frequencies are supplied to a mixer circuit which provides the difference frequency, used as the drive frequency for the synchronous or stepping motor connected to the mixer circuit. The motor is used to move the clock hands. The two oscillators have separate piezoelectric resonators, or may have a common piezoelectric resonator, such as a quartz crystal, with two electric fields, generated by at least three electrodes, the resonator generating preferably transverse shearing oscillations.