Abstract: A system and method for driving a stepper motor utilizing a near minimum amount of driving power is described. A stepping detector is utilized to determine whether the motor has actually stepped in response to a driving power applied thereto. When it is determined that the motor has stepped, the magnitude of the driving power is decreased. When the stepping detector indicates a stall condition, the driving power is increased. As a result, the motor operates near stall condition and power consumption is minimized. In the preferred embodiment during each consecutive step a different phase of the motor is deenergized to conserve power. By stepping the motor a voltage pulse is induced into the deenergized phase. The polarity and magnitude of that voltage pulse are examined after each step to determine whether the motor has actually stepped. The use of the deenergized phase to ascertain motor status eliminates the need for an external stepping detector.

Abstract: A method of analyzing the voltage induced in an exciter coil of a stepping motor. After energization the exciter coil is loaded by a low impedance so that the induction voltage can produce a current. Subsequently, it is attempted to maintain the current through said coil equal to zero by periodically connecting said coil to a positive or negative voltage. The pattern of consecutive polarities of these periodic energizations is analyzed.

Abstract: In a wristwatch movement with a stepping motor with a rotor connected to drive a gear train which periodically advances the hands of the wristwatch, the stepping motor has a flat stator piece secured in a plastic movement frame. A coilcore assembly comprising a flat hook-shaped core plate having a straight core portion of uniform width with a coil inserted over the free hand of the core portion is secured to the stator so that opposite ends of the hook-shaped member overlap opposite ends the stator to complete a path for the magnetic flux. The hook-shaped coil core is placed on top of the stator during assembly and is held down by insulated clamping means such as a bridge or circuit board bolted to the frame at the time of final assembly. Preferably, the stator and coil core member are located with respect to one another by plastic studs integral with the frame extending through aligned holes in the stator and coil core. Some of the studs receive bolts which hold the clamping means to the frame.

Abstract: The application discloses two time clocks interconnected by a transmission, one clock is driven by a 60 cycle synchronous motor for standard time which drives the second clock at fast time for six months then slow time for six months.

Abstract: An analog clock comprises an oscillator circuit for producing a signal having a predetermined frequency, a circuit for frequency-dividing the output signal of the oscillator circuit so as to produce a clock pulse signal and adjustment pulse signals having a period different from that of the clock pulse signal, a manipulation part for producing an adjustment instruction signal responsive to a time adjustment made in the manipulation part, a circuit for producing a driving pulse signal from one of the clock pulse signal and the adjustment pulse signals depending on the adjustment instruction signal and for supplying the driving pulse signal to a coil for forward rotation or to a coil for reverse rotation, and a stepping motor having a rotor which is rotated in the forward (or reverse) direction by a predetermined angle responsive to an excitation of the coil for forward (or reverse) rotation by one pulse of the driving pulse signal. Hands of the analog clock are rotated by the rotation of the rotor.

Abstract: A step motor driving control mechanism for use in an electronic timepiece for reducing the current consumption thereof is provided. Load detection circuitry detects the load condition of the step motor and selectively produces a load condition signal representative of a predetermined load condition thereof. Driving and control circuitry is provided for receiving a low frequency timekeeping signal produced by a divider circuit and a load detection signal when same is selectively produced by the load detection circuitry. In response to the presence or absence of a load detection signal applied thereto, the drive and control circuitry is adapted to vary the duration of the pulse width of a drive signal applied to the step motor to effect a driving of same.

Abstract: In a control system for a step motor having a rotor and stator, small velocity coils are placed in the stator in quadrature to the main power phase windings. The velocity coils provide velocity feedback signals which are summed with current command signals to gradually damp the step motor. The damped step motor is effective in minimizing its rotor from oscillating about a desired stopping point.

Abstract: In an electronic analogue timepiece driven by a stepping motor, DC magnetic field detector is connected to the stepping motor to detect the presence of an external DC magnetic field by comparing two induced voltages induced across a motor coil due to free rotation of a motor rotor after each application of two successive drive pulses to the motor coil. A controller is connected to the DC magnetic field detector to control the stepping motor to effect compensation for the detected DC magnetic field.

Abstract: The timepiece comprises a first motor for driving a second hand and a second motor for driving minute and hour hands.When the timepiece is operating normally, the first motor, which comprises at least two coils, is controlled continuously by variable voltages in such a way that its rotor is subjected to a rotating magnetic field and that the second hand moves forward by effecting at least five jumps per second. Furthermore, these voltages are preferably such that the rotor effects one revolution per minute, it therefore being possible to fix the second hand directly to the rotor shaft.The second motor is a conventional, preferably bidirectional stepping motor.

Abstract: The method according to the invention is applicable to motors comprising a magnetized rotor having two diametrically opposed poles, a stator making up a magnetic circuit having saturable constricted portions and a coil coupled magnetically to the stator. The method consists in applying to the coil an electric pulse, in measuring a control current (I'.sub.01, I'.sub.02) generated within the coil by the electric pulse at the end of a control time interval (t'.sub.o -t.sub.i) and in comparing the control current with a reference current (I.sub.r), the sign of this comparison being representative of the position of the rotor. In order to take into account the variations in the characteristics of the motor with time, the control time interval (t'.sub.o -t'.sub.i) is readjusted periodically by means of first and second electric pulses of a learning signal applied to the coil. The first pulse of this signal generates within the coil a first current (I.sub.1) which reaches the reference current (I.sub.

Abstract: The base plate bears on one of its surfaces a motor for counting off current time and two motor units for counting off minutes and hours of measured time intervals. On the lower surface it bears a motor for counting off seconds of measured time and a motor for counting off hundredths of seconds of measured time, these latter being partially superposed over the motors on the other surface. A tube is placed so as to locate and guide by its outer surface the display wheel train driven by the current time motor and by its inner surface the display wheel train driven by the motors which count seconds and hundredths of seconds of measured time. Two substrates placed respectively above and below the motors are connected by contact blocks. A control circuit and a quartz resonator are fastened to the lower substrate. The battery is accommodated in a lodging adapted thereto and its thickness extends to both surfaces of the base plate.

Abstract: The invention relates to an electric watch, wherein the rotor of a stepping motor is arranged between the metal frame and the plastic frame and is mounted in bearing holes of these frames or base plates. In accordance with the invention, the plastic frame has adjacent to the bearing hole of the rotor a partially cylindrical web extending substantially perpendicular to the metal frame and penetrating the air gap between the rotor and the stator of the stepping motor, while the stator with the associated coil is mounted on the outer side of the plastic frame. This construction enables assembly of the rotor without the effects of disturbing magnetic interaction between rotor and stator tending to dislocate the rotor.

Abstract: A stepping motor for use in a clock includes a rod core having an effective length L, and a coil wound around the rod core along the effective length L and having a thickness R defined between the center of the rod core and the outermost periphery of the coil. The effective length L and the thickness R satisfy the relation 10.ltoreq.L/R.ltoreq.40. A stator is magnetically connected between the ends of the rod core. A rotor is rotatably disposed between opposed magnetic poles of the stator, and the rotor has a circular shape of a radius r.sub.0 in the range of 1 to 2 mm. Electric pulses having a pulse width t in the range of 9 to 17mS are applied to the coil so that the stepping motor converts more than 20% of the electric energy of the pulses into rotational torque of the rotor.

Abstract: A detection circuit having a normally open low impedance loop comprised of a step motor coil and a low impedance element, and a normally open high impedance loop comprised of the step motor coil and a high impedance element is used to detect whether or not the step motor has angularly advanced in response to application of a drive pulse to the step motor coil. The detection circuit is driven by alternately switching between the low and high impedance loops to thereby alternately close the loops to enable detection of a voltage induced in the step motor coil indicative of whether or not the step motor rotor has angularly advanced in response to the application of a drive pulse to the step motor coil, and the alternate switching between the low and high impedance loops is controlled so as to prevent occurrence of a condition in which the low and high impedance loops are both open simultaneously during detection of the induced voltage.

Abstract: Circuitry for measuring the torque of a stepping motor is disclosed. The circuitry is based on the fact that the decay time of the current flowing through the stator coils is a function of the torque of the stepping motor.

Abstract: A movement for a two-hand quartz analog watch driven by a Lavet-type stepping motor has a minute hand on a shaft driven by a large center wheel overlapping the energy cell. The center wheel has 60 radial slots directly engaging and driven by the stepping motor rotor through a pair of diametrically opposed driving pins disposed in adjacent radial slots of the center wheel. The driving circuit steps the rotor 180 degrees once each minute. A reduction gear drives the hour hand mounted on a center pinion.

Abstract: The purpose of the invention is the realization of a motor assembly formed from a stepping motor and its control circuit capable of operating at a maximum speed substantially greater than that obtainable with comparable existing assemblies.This is effected by substituting for the single coil or for each coil of a known motor two or more windings and adopting a control circuit which connects the windings in series or parallel according to whether motor drive pulses of low or high frequency are applied thereto. The total number of winding turns and the sum of the resistances of the windings are preferably chosen to be equal respectively to the number of turns and the resistance of the coil which they replace in order to avoid basic modification of the characteristics and performances of the motor when operating at low speed.When the windings are connected in parallel their resistance and equivalent self-inductance are less than that of a single coil.

Abstract: The control circuit comprises means for measuring current flow in the motor winding including an auxiliary transistor and means to form periodically a current mirror from such auxiliary transistor and one of the transistors coupled to the winding for applying thereto energization pulses, i.e. motor drive pulses, catch-up pulses or check pulses.

Abstract: A step motor driving control mechanism for use in an electronic timepiece for reducing the current consumption thereof is provided. Load detection circuitry detects the load condition of the step motor and selectively produces a load condition signal representative of a predetermined load condition thereof. Driving and control circuitry is provided for receiving a low frequency timekeeping signal produced by a divider circuit and a load detection signal when same is selectively produced by the load detection circuitry. In response to the presence or absence of a load detection signal applied thereto, the drive and control circuitry is adapted to vary the duration of the pulse width of a drive signal applied to the step motor to effect a driving of same.

Abstract: A method of controlling a stepping motor comprises supplying the motor with a predetermined quantity of energy E.sub.io from whence there will result an automatic adaptation of the width of the motor drive pulse to the voltage U.sub.o at the motor terminals and the resistance R.sub.i of the energy source. At the moment when the internal energy E.sub.i (t) supplied to the motor, as defined by the integral over a time period of the product of U.sub.o -RI and the current I.sub.t circulating in the motor winding, becomes equal to E.sub.io the drive pulse is cut off (R is the resistance of the motor winding). The circuit for practicing the method according to the invention includes means for measuring the voltage U.sub.o and the energizing current I(t), means for obtaining the difference U.sub.o -RI, a multiplier for forming the product (U.sub.o -RI)I(t) and an integrator the output of which provides a voltage proportional to the internal energy E.sub.i (t).

Abstract: The device includes two driving circuit (C.sub.1, C.sub.2) each of which includes six power transistors (T.sub.11 -T.sub.16, T.sub.21 -T.sub.26) that are connected in pairs into three parallel circuit branches. A first coil (B.sub.11) of one of the motors and a first coil (B.sub.21) of the other are, on the one hand, both connected to the junctions of the transistors of one of the branches of one of the driving circuits (C.sub.1) and, on the other hand, respectively connected to the junctions of the transistors of the two other branches of this circuit. The same applies for the second coils (B.sub.12, B.sub.22) of the motors and the other driving circuit (C.sub.2). The various transistors are controlled so that the two coils of the same motor simultaneously receive the current pulses which are needed to make it turn but by preventing the simultaneous application of current pulses to a coil from one of the motors and to a coil from the other.

Abstract: A method by means of which the damping of the rotor and of the load of a multiphase motor can be increased when it is desired to stop the rotor and the load in a certain position consists in measuring the voltages induced by the movement of the rotor in the different stator phase windings and modifying the currents applied to these windings as a function of the measurements made, so as to produce an electromagnetic-type damping torque. A device for carrying out this method comprises circuitry for measuring the induced voltages in the phase windings and circuitry by means of which currents depending on such measurements of the induced voltages can be applied to these phase windings.

Abstract: The method involves supplying to the motor drive pulses generated by a control circuit, determining by means of a measurement circuit a physical magnitude representative of the motion of the rotor, interrupting the drive pulse at a given instant defined by a calculating circuit according to the time taken by the physical magnitude to reach, in a comparator, a reference level, controlling by means of a missed step detecting circuit whether or not the rotor has effected a step, retrieving if need be a non-effected step, summing the number of missed or non-effected steps in a counting circuit, and modifying in a reference circuit the reference level depending on the number of steps that have been missed in a given period of time.The device for putting this method into operation enables the motor to operate under optimal security and energy consumption conditions and can be used to advantage in timepieces.

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.

Abstract: 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.

Abstract: An electronic timepiece having hands incorporates a correction system whereby the user can rapidly and easily check that the operations of the hands are synchronized, and can adjust the state of synchronization if necessary, by initiating an operating mode in which the hands should rotate to indicate a predetermined reference time value. This checking and adjustment can be carried out at any time, irrespective of the current state of timepiece operation.

Abstract: Circuits are provided for avoiding misdetection of a non-rotated condition after driving the timepiece stepping motor. Voltages induced in the rotor coil by external high frequency magnetic fields, and current produced in the coil by lower frequency AC magnetic fields are detected. When a high frequency or AC magnetic field of sufficient intensity to cause a false indication of motor rotation is detected, the motor is next driven with a pulse having greater width than the normal driving pulse so as to assure operation of the motor. A period is provided, before the normal driving pulse would be applied, to detect AC magnetic fields and a period preceding the period for detection of AC magnetic fields is provided for detection of high frequency magnetic fields. A comparator or inverter is used to determine whether the levels of external magnetic fields are sufficient to cause misdetection of rotor position.

Abstract: An electronic analog display timepiece provides multifunctions wherein the hand, or hands, is driven at different frequencies. To prevent erroneous performance of the step motor, an interval longer than the period of damped oscillation of the step motor is provided when the step motor driving frequency changes by synchronizing the lower frequency driving signals with the signal of the highest frequency of the circuit. Alternatively, one pulse of the second frequency signal is eliminated when switching from the first to the second frequency signal.

Abstract: The analog electronic timepiece has a plurality of functions, each driven independently by a dedicated step motor. A stem, pullable to three positions and a plurality of pushbuttons control operation. Each indicator hand may be set to zero independently by operation of an external button when the electronic circuits indicate that the respective hand should be at the zero position. A single frequency signal source and divider network provide frequency signals to all functions. Phase shifting circuits assure that driving signals to the independent motors are never concurrent.

Abstract: A step motor driving control mechanism for use in an electronic timepiece for reducing the current consumption thereof is provided. Load detection circuitry detects the load condition of the step motor and selectively produces a load condition signal representative of a predetermined load condition thereof. Driving and control circuitry is provided for receiving a low frequency timekeeping signal produced by a divider circuit and a load detection signal when same is selectively produced by the load detection circuitry. In response to the presence or absence of a load detection signal applied thereto, the drive and control circuitry is adapted to vary the duration of the pulse width of a drive signal applied to the step motor to effect a driving of same.

Abstract: An electronic timepiece having a step motor is driven by a drive circuit which selectively produces either continuous hand-carrying pulses or stepwise hand-carrying pulses. The continuous hand-carrying pulses are produced by a continuous hand-carrying waveform shaping circuit connected to a frequency divider, and the stepwise hand-carrying pulses are produced by a stepwise hand-carrying waveform shaping circuit connected to the frequency divider. The selection of either the continuous hand-carrying pulses or the stepwise hand-carrying pulses is executed by a hand-carrying mode selection circuit in response to the operation of a reset switch for resetting the frequency divider.

Abstract: The present control device is used in connection with a diphase or polyphase stepper motor in which the coils of two phases (b.sub.i, b.sub.j) are not simultaneously supplied with driving current. A commutation circuit CC is adapted to connect the coils to a voltage source V or to a detection circuit CD. A logic control circuit CL.sub.1, CL.sub.2, CL.sub.3, itself controlled by a clock signal source G.sub.1 and by a generator of programmed control pulses PG, supplies control signals to said circuits CC and CD. The control device provides a feedback control of the motor as a function of the speed and the position of the rotor at various instants of the control cycle in accordance with a predetermined program so as to assure perfectly reliable operation of the motor with a minimum of electric energy even for motors manufactured with rather wide manufacturing tolerances.

Abstract: The invention concerns a method for controlling a bidirectional stepping motor having two windings and three pole faces.The invention comprises applying current pulses alternately to only one of the motor windings to cause it to rotate in one direction and to only the other of the motor windings to cause it to rotate in the other direction.The invention is used for controlling bidirectional motors which are employed in particular in timepieces.

Abstract: In an electric clock movement, the electronic components, such as an IC chip (9), a quartz crystal (10) or a diode (12), instead of being fastened to a circuit board are fastened to an extension (8) on the back plate (2). For this purpose, the extension (8) is provided with holes (14) into which the leads (15) of the electronic components are inserted.

Abstract: In an electronic analog timepiece an automatic sequence of events determines the proper magnitude of a detection resistor which is used in series with the motor coil so as to determine whether in normal operation the rotor is rotated or not when driven. A detection resistor is used in series with motor coil but only after a fixed time has passed from initiation of detection current flow. The detection resistor is logically variable and selected automatically in accordance with the motor's mechanical load at the time of switching on the power source or releasing the analog timepiece from a resetting operation. The resistance is formed part of the integrated circuit.

Abstract: A method and an apparatus for controlling and regulating an electrical motor, especially a reactive motor for time-keeping devices such as clocks. The motor has a permanent-magnetic rotor with at least two poles, and a stator with at least two coils. In a normal speed mode one of coils is supplied with driving pulses whereas the second coil senses the rotational speed of the rotor. If the rotational speed of the rotor falls below a predetermined value, a self-starting mode is initiated wherein the first and second coils are alternately supplied with driving pulses. In this self-starting mode the frequency of the pulses supplied to the first and second coils is increased until normal speed has been reached wherein the self-starting mode is switched off and the normal speed mode regulation is switched on.

Abstract: An analog electronic timepiece comprises a stepping motor having a stator, rotor and drive coil, and electronic circuitry for periodically energizing the drive coil in two distinct excitation states to rotationally drive the rotor in a stepwise manner. The electronic circuitry effects sequential energization of the drive coil in first a full excitation state which is effective to at least initiate driving of the rotor from an initial position through a predetermined angle of rotation to a new position, and then in an intermediate excitation state which is effective to ensure completion of the driving of the rotor through the predetermined angle of rotation by preventing return rotation of the rotor after the rotor has advanced through a certain angular extent towards its new position.

Abstract: The motor unit comprises a stator, two independent rotors having each a permanent magnet located in a cylindrical space defined by three pole faces of the stator, two windings and at least a positioning magnet for holding both rotors, in the absence of current in the windings, in a position in which the magnetic axes of their magnets are each coincident with a rest axis. The field produced by the flow of a current in one of the windings is always at an obtuse angle to one of the rest axes and at an acute angle to the other.The two rotors perform steps of 360.degree. independently of each other in response to pairs of current pulses, the first of which is applied to one of the windings and the second of which is applied to the other winding. The direction of the current pulses determines which of the rotors performs a step, and the order in which the current pulses are applied to the windings determines the direction of rotation of that rotor.The motor unit can be used in particular in an electronic timepiece.

Abstract: A stepper rotor is driven with a narrow pulse width input which matches the load conditions on the motor. The subsequent position of the rotor is detected as being rotated or non-rotated by application of a detection pulse to the rotor. An additional driving pulse of increased width is applied should the rotor be found in a non-rotated state. A stabilizing pulse prevents intermediate rotor positioning. Position of the stepper motor is detected by passing a current through the rotor cell. The rate of increase in detection current is different when the rotor has rotated and when the rotor does not rotate because coil inductance and magnetic flux directions passing through the saturable portion of the stator are different depending upon the position of the rotor. The width of the driving pulse for normal operation is selected from a range of pulse widths so as to match the load on the motor.

Abstract: The motor comprises a stator with three pole pieces having pole faces which define a cylindrical space, two windings which are magnetically coupled to the first and the second pole piece, and to the first and the third pole piece respectively, a rotor which is concentric with respect to the cylindrical space and which comprises a first permanent magnet, and a second permanent magnet coupled with the first magnet for holding the rotor, in the absence of any other influence, in a position in which the magnetic axis of the first magnet coincides with a rest axis. The field produced in the cylindrical space by the flow of a current in any one of the windings is at an obtuse angle to the rest axis.The rotor performs 360.degree. steps in response to pairs of current pulses, the first of which is applied to one of the windings and the second is applied to the other of the windings.

Abstract: The present invention concerns a method and a device for reducing the consumption of a stepping motor by automatically adapting the duration of each drive pulse supplied to said motor to the mechanical load that its rotor is to drive.The method comprises forming each drive pulse by a series of elementary pulses separated by interruption periods, and determining the mechanical load by measuring, during said interruption periods, a parameter which is representative of the variation in the voltage induced in the winding (11a) of the motor by the rotary movement of the rotor.

Abstract: 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.

Abstract: The present invention concerns a method and a device for controlling a stepping motor of a timepiece, which permit the power of each drive pulse to be adapted to the value of the electromotive force (V) and/or the internal resistance (R*) of the power supply source (10).In accordance with the invention, at a given moment, a value of a chopping rate (Ha) is determined in dependence on the value of the electromotive force V and/or the internal resistance R* of the power supply source (10), said value being stored, and the chopping rate of each control pulse being adjusted to the stored value.The control device comprises means (13) for supplying a chopping signal (M) to a drive circuit (12) of the motor (11). The chopping rate is determined by information contained in a memory (14). The stored information is periodically corrected in dependence on the value of the electromotive force (V) and/or the internal resistance (R*) of the power supply source (10).

Abstract: The motor assembly comprises a bidirectional stepping motor having a coil, a stator provided with a central opening in which is mounted for rotation about an axis a rotor including a permanent magnet which is magnetized along an axis of magnetization, and positioning means for defining two rest positions of the rotor in which the axis of magnetization of the magnet is directed along an axis of static equilibrium. The stator is formed of two pole pieces which partly surround the rotor and are interconnected by two intermediate parts and by four isthmuses in such a manner that the intermediate parts are intersected by the axis of static equilibrium and that two isthmuses which are opposite each other in relation to the axis of rotation of the rotor are located in one direction making with the axis of static equilibrium an angle of between 30.degree. and 60.degree..

Abstract: In an electronic timepiece utilizing a stepping motor, voltage induced in the electromagnetic coil of the motor due to free oscillation of a rotor thereof is detected in a plurality of successive detection periods after application of a driving force to the motor is completed, and it is determined on the basis of such induced voltage for the respective detection periods whether the rotor failed to step or not. If the stepping failure is determined in at least one detection period, a compensation pulse is fed to the stepping motor to compensate for the stepping failure of the rotor and thereafter driving energy supplied to the electromagnetic coil of the motor is increased.

Abstract: 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.

Abstract: The method comprises measuring the voltage induced during the driving pulse in the coil by rotation of the rotor, and interrupting the drive pulse in dependence on the measurement made.The device for carrying out this method comprises a circuit for measuring the induced voltage, a circuit for comparison with a reference value and a circuit for calculating the duration of the drive pulse.

Abstract: An electronic analog timepiece with time zone and time setting modes selected by appropriate rotation and axial movement of a crown that controls a high speed stepping motor is disclosed. The stepping motor provides high frequency signals to produce time correction rotation of the timepiece hands. The speed of the stepping motor is reduced by a deceleration ramp from high speed prior to stopping the motor at the end of time correction. The time setting mode may be selected when the watch is in the shutdown mode and the time zone mode is selected when the watch is in the normal clockwise running mode by rotating the crown in either the clockwise or counterclockwise direction. The shutdown mode may be selected from the normal running mode by pulling the crown to its out/setting position and the normal running mode may be selected from the shutdown mode by pushing the crown to its on/run position.

Abstract: A driver circuit for a stepping motor having a coil, a stator and a rotor receives pulse signals from a pulse signal generator to rotationally drive the rotor. A rotation detection circuit comprises switching circuitry switchable between a high impedance loop formed of the coil and a high impedance element and a low impedance loop formed of the coil and a low impedance element, and means for detecting the voltage induced in the coil. After a pulse signal is applied to the stepping motor, the switching circuitry forms the high impedance loop and the detecting means compares the voltage developed across the high impedance element with a predetermined voltage to thereby detect the rotation and non-rotation states of the rotor.

Abstract: In an electronic timepiece having two stepping motors, one for driving at least a second-hand and the other for driving at least an hour-hand, rotation or non-rotation of the rotor of said other stepping rotor is detected and when non-rotation is detected, failure of stepping of said other stepping motor is determined and said one stepping motor is controlled to be actuated in a warning mode which is different from a normal mode to give warning of the failure of stepping of said other stepping motor.