摘要:
A motor driving power supplying section obtains an output voltage by switching-controlling a predetermined voltage outputted from a main power supply and smoothing a voltage thus switching-controlled. A driving transistor group includes a plurality of driving transistors, for supplying electric power based on the output voltage of the motor driving power supplying section to the motor driving coils of multiple phases. A commutation control section supplies conduction switching signals to the driving transistor group so as to switch successive conduction states of the motor driving coils. An output control section controls the output voltage of the motor driving power supplying section so that a collector-emitter voltage of at least one of the plurality of driving transistors included in the driving transistor group has a predetermined value. A torque control section controls conduction current intensity to the motor driving coils by controlling output currents of the plurality of driving transistors included in the driving transistor group.
摘要:
A motor driving device includes (a) a wide-angle feeding device for feeding power to three-phase coils in a width of 150 degrees in electrical angles and (b) a feeding amount controller for controlling a feeding amount to the coils. During overlapping periods, in which adjacent coils out of the three coils are in the same fed condition, an amount of a first value is fed to the coils and an amount of a second value is fed during the periods other than the overlapping periods. This structure allows the motor to reduce torque ripples, vibrations as well as noises during its operation, and at the same time, the motor can produce a greater output and operate at higher efficiency.
摘要:
A speed control apparatus for a motor, wherein the counter-electromotive voltage is detected with great precision even when the counter-electromotive voltage to be caused from the motor driving coils is small or the ambient temperature is changed. The voltages corresponding to the detection voltages are turned into speed signals. The emitter resistance of the driving transistor, which is the cause of the torque reduction, can be removed, and uneven rotation, uneven torque is reduced. The speed control apparatus provides a composite voltage of driving coil voltages that are converted by an inversion amplifier. The voltage corresponding to the composite voltage provides the speed signal. This voltage is transferred to the driving coils and precise speed control is produced without a reduction in the controllable maximum torque or the starting torque.
摘要:
With a view to reduce vibrations generated by a motor and improve resistance to heat, reliability and vibration isolation properties without increasing the cost or the number of manufacturing steps in a rotor for a permanent-magnet motor, a rotor core is formed of an outer peripheral portion by which the permanent magnet is fixed, and a central portion by which a shaft is fixed, a clearance is provided between the outer peripheral portion and the central portion, and the outer peripheral portion is connected to the central portion by means of a plurality of fastening members. Thus, a rotor having excellent vibration isolation properties can be obtained. Since the rotor core is formed of laminated iron plates on which the outer peripheral portion, the central portion and the fastening members are all formed as one piece, resistance to heat, reliability and the vibration isolation properties can be enhanced without increasing the cost or the number of manufacturing steps.
摘要:
A brushless motor driving device includes a plurality of motor driving coils and a plurality of driving transistors, coupled to the motor driving coils, for periodically supplying an electric power to the motor driving coils. A power supply switching circuit is provided for generating a power supply switching signal for driving the motor driving coils on the basis of a frequency signal corresponding to an oscillation frequency of a voltage controlled oscillator. A phase difference detector is provided for detecting a difference between the power supply switching signal and a counterelectromotive voltage generated in the motor driving coils during a period in which no electric power is supplied to the motor driving coils. The phase difference detected by the phase different detector circuit is used to control the oscillation frequency of the voltage controlled oscillator.
摘要:
A drive apparatus for use in a brushless motor with a rotor and a drive coil assembly. The drive apparatus comprises an energization-state instruction circuit for generating an energization-state instruction signal instructing an energization state of the drive coil assembly on the basis of the position detection signal indicative of a position of the rotor and an energization switching circuit for outputting an energization switching signal to successively switch the energization state of the drive coil assembly in accordance with the energization-state instruction signal and a duty control signal. A power circuit is coupled to a direct-current voltage source and is responsive to the energization switching signal so as to energize the drive coil assembly by means of a direct-current voltage from the direct-current voltage source in accordance with the energization switching signal therefrom. A duty control circuit is responsive to a speed instruction signal from a speed instruction circuit and a motor speed signal from a speed detecting circuit for outputting the duty control signal to the energization switching circuit so as to control a duty ratio of the energization-state instruction signal on the basis of the duty control signal so as to output the energization switching signal to be inputted to the power circuit.
摘要:
In a system for driving a brushless motor having motor drive coils connected to respective drive transistors, voltages induced in the drive coils when the motor is rotating are continuously detected to produce energization switching signals to be applied to the drive transistors, thereby switching over energization of the drive coils, so that the motor can be continuously driven at optimum energization timing regardless of its rotational speed. Further, when a rotational direction command signal is applied to a forward-backward switching circuit to instruct the motor to rotate in the backward rotational direction while the motor is rotating in the forward rotational direction, torque of the opposite direction is produced to change the rotational direction of the motor. Further, separate-excitation timing pulse signals are used to sequentially switch over energization of the motor drive coils when the motor is not rotating or it is rotating at a very low speed, and hence voltages induced in the motor drive coils cannot be detected. As soon as the voltages induced in the drive coils have become able to be detected due to the rotation of the motor, self-excitation timing pulse signals are then used to sequentially switch over energization of the drive coils.
摘要:
The present invention relates to a drive device for a brushless motor utilizing no position detector for detecting the position of a movable element of the motor.The drive device comprises a phase controlled loop for controlling an output of a voltage controlled oscillator (40) by supplying an electric power to motor driving coils (1, 2, 3), detecting the difference in phase between the power supply waveforms thereof and a counterrelectromotive force of the motor driving coils during a power supply interrupting period with the use of a phase difference detector (20) and inputting a detected phase difference signal to the voltage controlled oscillator (40), an oscillation frequency initializing means (70) and a driving transistor interrupting circuit (80).
摘要:
A phase difference between a counter-electromotive voltage induced in a driving coil and a voltage which is applied to the driving coil is detected by comparison of a terminal voltage of the driving coil and a reference voltage. A frequency of a voltage-control oscillator which controls switching of the voltage applied to the driving coil is varied by an output signal made by the comparison, and the phase difference is controlled to be reduced to zero.
摘要:
The present invention is directed to a motor current phase detecting device that drives a motor having a three-phase drive coil, the device including a power distributor that supplies a drive voltage and a drive current to the drive coil, a current detector that detects a common current waveform flowing from the power distributor, a position detector that detects a position of a rotor, a waveform generator that generates a first PWM signal, a waveform regulator that generates a second PWM signal based on the first PWM signal, and a current phase detector that detects a phase of a drive current flowing in each of the drive coil. The waveform regulator generates the second PWM signal that operates a current phase detector while maintaining a relative voltage value between the drive coils determined by the first PWM signal, and the current phase detector detects the phase of the drive current of the drive coil by detecting a peak current value of the drive coil included in the common current waveform based on the second PWM signal.