Abstract: Two standard waves from a standard waveform generation circuit are output via an output gate while being interchanged by a direction selector. The switching operation of the direction selector is controlled by a direction control signal M/I. 200 cycles of the standard waveforms are counted up by a 200-cycle counter. A drive counter is downcounted every 200 cycles, while the drive counter is upcounted in accordance with the number of drive pulses DRIVE. When the count value of the drive counter becomes zero, output from the output gate is thereby stopped. At the time of startup, outputs from the 200-cycle counter are counted so as to output a drive wave in a predetermined number in a predetermined direction.

Abstract: Two standard waves from a standard waveform generation circuit are output via an output gate while being interchanged by a direction selector. The switching operation of the direction selector is controlled by a direction control signal M/I. 200 cycles of the standard waveforms are counted by a 200-cycle counter. A drive counter is downcounted every 200 cycles, while the drive counter is upcounted in accordance with the number of drive pulses DRIVE. When the count value of the drive counter becomes zero, output from the output gate is thereby stopped.

Abstract: A single phase motor driving unit includes: a first driving transistor supplying a single phase coil with a driving electric current in a certain direction; a second driving transistor supplying the single phase coil with a driving electric current in the opposite direction; a comparison section comparing an intensity of a sine wave signal obtained from a Hall device detecting a rotational position of a single phase motor and a reference value, and generating a timing signal in a predetermined period starting immediately before and ending immediately after a point at which the direction of the driving electric current for the single phase coil changes; and a recirculating section recirculating the driving electric current by controlling ON-OFF timings of the first and the second driving transistors in the predetermined period in which the timing signal is generated such that, within a given period in which the first and the second driving transistors on the side to which the driving electric current flows out

Abstract: A single phase motor driving unit comprises a first driving transistor supplying a single phase coil with a driving electric current in a certain direction, a second driving transistor supplying the single phase coil with a driving electric current in the opposite direction, and a recirculating section which recirculates the driving electric current for the single phase coil by controlling on-off timings of the first driving transistor and the second driving transistor in a predetermined period immediately before the direction of the driving electric current for the single phase coil changes.

Abstract: A single-phase motor driving circuit includes a controller for outputting a control signal to drive a single-phase motor in a period in which a saw-tooth voltage of a predetermined cycle is larger than a duty setting voltage based on a result of comparing a detected temperature voltage changed based on a temperature detected by a temperature detecting device with a starting duty setting voltage increased with time while a voltage smaller than the detected temperature voltage at the time of starting the single-phase motor is set as an initial value. The controller sets the duty setting voltage as the starting duty setting voltage when the result of the comparison shows that the starting duty setting voltage is smaller than the detected temperature voltage, and the duty setting voltage as the detected temperature voltage when the starting duty setting voltage is larger than the detected temperature voltage.

Abstract: A single phase motor driving unit includes: a first driving transistor supplying a single phase coil with a driving electric current in a certain direction; a second driving transistor supplying the single phase coil with a driving electric current in the opposite direction; a comparison section comparing an intensity of a sine wave signal obtained from a Hall device detecting a rotational position of a single phase motor and a reference value, and generating a timing signal in a predetermined period starting immediately before and ending immediately after a point at which the direction of the driving electric current for the single phase coil changes; and a recirculating section recirculating the driving electric current by controlling ON-OFF timings of the first and the second driving transistors in the predetermined period in which the timing signal is generated such that, within a given period in which the first and the second driving transistors on the side to which the driving electric current flows out

Abstract: A single-phase motor driving circuit includes a controller for outputting a control signal to drive a single-phase motor in a period in which a saw-tooth voltage of a predetermined cycle is larger than a duty setting voltage based on a result of comparing a detected temperature voltage changed based on a temperature detected by a temperature detecting device with a starting duty setting voltage increased with time while a voltage smaller than the detected temperature voltage at the time of starting the single-phase motor is set as an initial value. The controller sets the duty setting voltage as the starting duty setting voltage when the result of the comparison shows that the starting duty setting voltage is smaller than the detected temperature voltage, and the duty setting voltage as the detected temperature voltage when the starting duty setting voltage is larger than the detected temperature voltage.

Abstract: A single-phase motor driving circuit includes a controller for outputting a control signal to drive a single-phase motor in a period in which a saw-tooth voltage of a predetermined cycle is larger than a duty setting voltage based on a result of comparing a detected temperature voltage changed based on a temperature detected by a temperature detecting device with a starting duty setting voltage increased with time while a voltage smaller than the detected temperature voltage at the time of starting the single-phase motor is set as an initial value. The controller sets the duty setting voltage as the starting duty setting voltage when the result of the comparison shows that the starting duty setting voltage is smaller than the detected temperature voltage, and the duty setting voltage as the detected temperature voltage when the starting duty setting voltage is larger than the detected temperature voltage.

Abstract: A single phase motor driving unit comprises a first driving transistor supplying a single phase coil with a driving electric current in a certain direction, a second driving transistor supplying the single phase coil with a driving electric current in the opposite direction, and a recirculating section which recirculates the driving electric current for the single phase coil by controlling on-off timings of the first driving transistor and the second driving transistor in a predetermined period immediately before the direction of the driving electric current for the single phase coil changes.

Abstract: A full wave signal E is compared with a trapezoidal wave signal G in a comparator to output a second comparison signal H. The full wave signal E is obtained through full wave conversion applied to a sine wave signal of a Hall element. The trapezoidal wave signal G is obtained by sampling and holding an attenuated signal F, obtained by attenuating the full wave signal E, at a trailing end of a first comparison signal D, and nulling the attenuated signal F at a subsequent leading end thereof. Then, the first and second comparison signals D, H are added up in an OR circuit to output an addition signal K, so that no drive current IL flows through the driving coils at a point near the former and latter halves of a phase changeover point. Near the former half of a phase changeover a point, the drive current IL is nulled before counter electromotive force Ec becomes small, enabling motor noise reduction.

Abstract: In a motor, drive transistors (7, 9) are turned off by drive signals I, J output from a control circuit (10) at a point adjacent to a phase changeover point of the energizing to drive coils (1, 2), so that no drive current flows through the drive coils (1, 2). Since the counter electromotive forces of the drive coils (1, 2) become small, the drive current can be eliminated before the drive current sharply rises. As a result, sharp dropping of the drive current can be prevented. This allows variation in rotational torque of a motor to be suppressed, and thus reduces vibrational noise in the motor.

Abstract: A light-received position detecting circuit includes a light receiving portion 10 formed by plural photodiodes arranged side by side for detecting light to generate a photoelectric current, and a resistor group RR formed by plural resistors RR1 to RRn-1 connected in series and the photodiodes are correspondingly connected to the respective resistors to divide the photoelectric current from a light emitting portion 31 into photoelectric current parts according to the position of generation of the photoelectric current. First and second current detecting amplifiers 12 and 16 for generating detection signals corresponding to the photoelectric current parts are connected to the opposite ends of the resistor group RR, respectively. A third current detecting amplifier 14 for dividing the light receiving portion 10 into light receiving sections and detecting the photoelectric current part is connected to selected one of the resistors located in the intermediate portion of the resistor group RR.