Step-by-step motor unit
AssigneeFabriques d'Horlogerie de Fontainemelon S.A.
InventorEric Klein
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Abstract
To increase the speed of rotation of a step-by-step motor in the forward or reverse direction, the motor is driven at its "synchronism" speed. For the motor to perform N steps at high speed involves applying a starting drive pulse that induces forward or reverse motion, then applying N-2 alternating maintenance pulses and finally applying a stopping pulse. Preferably, a circuit using the coupling coefficient of the motor as a servo-control parameter defines the instants at which the maintainance or stopping pulses are applied.
Claims5
A motor unit comprising a stepping motor having a rotor and a stator fitted with a coil, and a control pulse generating circuit for applying drive pulses to said coil to cause the rotor to rotate N steps at high speed, said rotor capable of a forward or reverse rotation of said N steps, said circuit comprising means for successively producing and applying to the coil:
- a starting drive pulse to initiate rotation of the motor in one of said directions;
- N-2 simple maintaining drive pulses of alternating polarity to cause the rotor to rotate N-2 steps in said one direction;
- and
- a simple stopping drive pulse having a polarity opposite to that of the last maintaining pulse,
- and means for controlling the time of application of said maintaining drive pulses and of said stopping drive pulse dependent on the angular position of the rotor.
Dependencies are inferred from the claim text.