Device for the maintenance and control of the oscillations of the balance wheel of a timepiece
AssigneeEbarches S.A.
InventorsIgor Scherrer, Pierre Hersberger
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Abstract
A device for maintaining constant the amplitude of the oscillation of an electro-magnetically driven balance wheel of a timepiece, whereby a first voltage is generated of an amplitude proportional to the amplitude of oscillation of the wheel. This is compared with a reference voltage and a signal is derived corresponding in amplitude and sign with the difference. This signal is then used to control the application of driving pulses to the balance wheel. The said driving pulses are preferably much shorter than one half-period of the balance wheel.
Claims12
A device for maintaining constant amplitude of oscillation of a balance wheel of a timepiece using an electrodynamic maintenance system, comprising means for generating a first signal the amplitude of which varies with the amplitude of said oscillation, means for generating a second reference signal, means for comparing said first and second signals and producing a third signal having a voltage level and polarity determined by said comparison, means for applying driving pulses to said balance wheel, and means for regulating said driving pulses in accordance with said third signal.
A device as recited in clam 1, further including means coupled to said comparing means for varying said third signal.
Dependencies are inferred from the claim text.