A reversible pulse-motor driving circuit comprising a steady driving circuit composed of an oscillator circuit, a frequency divider circuit, a waveform conversion circuit, and a driving circuit, and a fast correction driving-circuit composed of a fast correction set-circuit, a first gate circuit, a detector circuit, a normal and reverse discrimination circuit, a conversion change-over circuit, a pulse selector circuit, a first memory circuit, a second gate circuit and a second memory circuit, whereby a user can hear a time signal delivered from a calculation circuit and only push a pushbutton to rotate the pulse motor in a reverse direction when the second hand is ahead of the correct time, and rotate the pulse motor in a forward direction when the second hand is lagging with respect to the correct time, and the use of a frequency higher than the steady driving frequency permits a fast setting of the second, minute or hour hand to the correct time. A reversible pulse motor for use in timepiece and more particularly in wrist watch is disclosed which can be rotated in forward and reverse directions by the driving circuit, which is small in size and which can operate with a minimal consumption of the electtric power.
A system for driving a bipolar stepping motor by a pair of pulse driving currents wherein an output level of a control circuit is selected depending on one of the pulse drive currents applied just prior to the stoppage of the motor by a reset signal, switching of a set of signal transmitting paths for connecting between a reference signal generating circuit and a motor drive circuit is selected depending on an output level of the control circuit, that one of a pair of reference signals produced by the reference signal generating circuit during the operation of the motor which first appears after the release of the stop causes production of the other of the pulse drive currents by the selected path, and a predetermined time period after the release of the stop the pulse drive current of opposite polarity to that of the pulse drive current being applied to the motor which is just about to stop is applied to the motor to positively re-start the operation of the motor at a predetermined time.
In an analogue electronic timepiece the hands are moved by a stepping motor driven by a time standard signal supplied from a generating circuit comprising a quartz oscillator. In order to amend the time in a reverse direction, for example to correct for a different time zone, means is provided for detecting the angular position of the rotor of the motor and for supplying current in the reverse direction to the coil of the motor when the rotor reaches a predetermined angular position so as to cause the motor to rotate in a reverse direction.
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.
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. Those pulses have always the same direction, and the order in which they are applied to the windings determines the direction of rotation of the rotor. The motor can be used in particular in an electronic timepiece.
