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.
A motor control circuit includes: a detector outputting a detection signal in accordance with the motor rpm; a counter counting the number of clocks in accordance with a rotational cycle represented by the detection signal; a controller counting a DC motor based on the count value; and a divider dividing a frequency of a basic clock based on a preset division value to generate a counting clock. The divider generates a counting clock having a frequency corresponding to a rotational cycle, and the counter counts the number of counting clocks.
A bi-directional stepping motor in which a rotor is rotatable in steps of 180 degrees each, the stepping motor comprising a rotor comprising a permanent magnet and rotatably mounted about an axis and providing a permanent magnetic field; a first electrical coil and a second electrical coil; a stator on which the first electrical coil is mounted; and a control circuit, coupled to the first and second electrical coils, for applying electrical pulses independently to each coil and for controlling the polarity thereof, the coils producing magnetic fields in response to the pulses and wherein the rotor is rotatable in response to the magnetic fields; wherein each step of 180 degrees is effectuated by providing to the first coil, a first pulse of a first polarity and a second pulse of a second polarity; and to said second coil, a pulse of the second polarity simultaneously with the providing of the second pulse to the first coil; wherein during the providing of the first pulse to the first coil, there is no pulse being provided to the second coil.
The present invention relates to an apparatus for driving a stepping motor, including a plurality of push-pull circuits each of which is capable of controlling a push state in which a current is supplied to a terminal and a pull state in which a current is drawn through the terminal and which are connected to coils to operate the stepping motor utilizing the bipolar driving. In the apparatus of the present invention, at least one of the push-pull circuits is connected to a common terminal having one ends of the coils of different phases connected thereto, thereby reducing the number of circuits and driving lines.
A drive control and interface apparatus housed within an advertising display for driving a stepper motor coupled to a display device to sequentially display a plurality of images. The drive control and interface apparatus includes a microprocessor having program memory connected to the motor through a motor driver. A drive control program operates the microprocessor to drive the stepper motor to change the image displayed after a corresponding predetermined period of time. The program includes drive routines for fast and slow image changes that drive the stepper motor to minimize resonance. A control interface connects to the microprocessor. The program is responsive to the control interface to permit manual sequencing of the display and user selection of the corresponding display times for each image.
