Societe Suisse Pour L'industrie Horlogere Management Services S.a.

Omega Sa

Mai Tu Xuan

Marcel Jufer

Andre Pittet

Michel Grosjean

An energizing method for a timepiece stepping motor provides just sufficient energy to the motor winding to assure a single step of the rotor with each driving pulse. With each pulse the winding is initially energized at a constant voltage (period T.sub.1) then at a constant current (period T.sub.2) between two limits Imax and Imin. When the time period .DELTA.T.sub.3 required for the current to pass from Imax to Imin is greater than a reference time period .DELTA.T.sub.ref. the energization is terminated. The invention may be employed in a wristwatch with the purpose of reducing energy consumption and increasing battery life.

Energizing method for a single phase timepiece stepping motor

The invention provides a feed arrangement enabling the detection of the rr position of a stepping motor in relation to polarity of the motor pulses and to apply a series of long duration pulses should the polarity be considered to be wrong. The detector includes means for sampling the induced voltage generated by the motor at a predetermined moment the motor being then open circuited, comparing said voltage with a reference signal and using the result of the comparison to determine whether or not the long duration pulses should be applied to the motor. The invention is intended for use with micromotors as used in timepieces.

Position detector for a stepping motor

A method for slaving a stepping motor proposes several levels of width of the control pulses U in order to adapt the torque provided by the motor to the load imposed thereon. The method includes measurement of the induced voltage Ui during a time interval T.sub.Ui situated immediately before the end of the control pulse U if the duration of such pulse does not exceed a predetermined duration T.sub.n (FIG. 8) or within a gap T.sub.x opened in the control pulse U if such pulse does exceed said predetermined duration T.sub.n (FIG. 11). The method may be applied to slaving stepping motors wherein the stator exhibits air gaps or saturable zones.

Method for slaving a stepping motor and arrangement for practising the

The invention comprises a single phase bipolar stepping motor in which the otor may rotate in both senses. A stator is provided having two windings. When these are connected in series and fed with a first type of alternating polarity pulses, the rotor turns in a preferred sense. When the windings are connected in parallel and fed by a second type of alternating polarity pulses of opposite phase to the first type the rotor turns in the opposite sense. The motor is applied to advantage in time setting arrangements for analog display timepieces.

Single phase bipolar stepping motor having two rotation senses

A feed arrangement enabling detection of the movement of a stepping motor d providing such motor with a series of long duration pulses in the event of failure to step responsive to a short duration pulse. The detector comprises means for sampling a first signal developed by the current in the motor winding and generating a second signal which is the integral of the first, in order to detect whether or not the motor has stepped. The invention is intended for use with micromotors as found in timepieces.

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Chavannes, Switzerland

Mai Tu Xuan