Techniques for controlling operations of a motor based on position errors are described. In an example, a user device sends an amount of electrical current to the motor to cause the motor to move. The user device also determines the motor is in position for a time interval despite the amount of electrical current. Based at least one the time interval and the amount of electrical current, the user device determines a position difference associated with a target position and a measured position of the motor during the time interval, and reduces the amount of electrical current based at least in part on the time interval.

A fan and a motor thereof are provided. The motor includes a motor drive device. The motor drive device includes a printed circuit board. A control management unit and a voltage converter are arranged on the printed circuit board, the control management unit classifies target rotation speed signals provided by an ECU into multiple rotation speed intervals, with each rotation speed interval corresponding to a fixed duty ratio. The control management unit receives a target rotation speed signal transmitted from the ECU in a real-time manner, and outputs a pulse width modulation signal having a duty ratio corresponding to the rotation speed interval to which the target rotation speed signal transmitted from the ECU belongs. The voltage converter is connected between the power source and the winding, and is configured to regulate a voltage outputted to the winding in response to the pulse width modulation signal having the fixed duty ratio outputted from the control management unit, to control a rotation speed of the motor. The motor drive device performs segment control on the rotation speed of the motor, thereby reducing the cost.

An apparatus for controlling a fluid pump for a motor vehicle includes: a first controller configured to actuate an electric prime mover of the fluid pump by impressing at least one motor current with an adapted current intensity and an adapted waveform; and a second controller configured to detect a rotational speed of the electric prime mover and to apply an adapted voltage to the electric prime mover on the basis of the detected rotational speed.

A closed-loop control device of a mechanical sewing machine includes an isolated switch-mode power supply module, a DC motor, a speed control module, a processor, an electronic switch, a current detection module and a voltage detection module. The isolated switch-mode power supply module rectifies an AC power to a DC power and supplies the DC power to the DC motor. The speed control module sends a speed signal to the processor. The processor adjusts an output voltage to the DC motor according to the speed signal. The current detection module and the voltage detection module further detect an operating current signal and an operating voltage signal of the DC motor for the processor to control a turn-on time of the electronic switch to adjust an average operating voltage of the DC motor according to the operating current signal, the operating voltage signal and the speed signal.

A fan control circuit with temperature compensation includes an on-off unit and a speed adjustment unit. When determining that a loading is greater than or equal to an adjustable start threshold according to a load signal, the on-off unit controls the fan entering a working mode. In the working mode and determining that the loading is less than a speed-adjusting threshold, the on-off unit maintains a speed value of the fan at a first fixed speed. When determining the loading is greater than or equal to the speed-adjusting threshold, the speed adjustment unit adjusts the speed value according to the loading. The speed adjustment unit generates a speed displacement according to a temperature signal to compensate the speed value.

Fan controller (1) for a modular power supply having a fan (13). An output (8) is provided for transmitting control signals to the fan (13) for controlling fan speed. A plurality of sensor modules (20) are associated with a respective module (11,6,7) of the modular power supply. Each sensor module (20) includes a temperature detecting circuit comprising a sensor for sensing temperature variations in the respective module (11,6,7), a fan control circuit (30) galvanically isolated from the temperature detecting circuit for outputting a control signal to the output (8) for controlling the fan (13), and an optocoupler (10,9) for transferring an output signal from the temperature detecting circuit (20) to the fan control circuit (30) for generating the control signal.

A contactless power supply and motor control system includes a pulse width modulator, a rotary transformer, a demodulator circuit, a motor driver, and a motor. The pulse width modulator supplies a first pulse width modulated (PWM) signal that has a duty cycle and a first amplitude. The rotary transformer receives the PWM signal. The secondary winding is rotatable relative to the primary winding and supplies a second PWM signal having the duty cycle and a second amplitude. The demodulator circuit is rotatable with the secondary winding and supplies a demodulated direct current (DC) voltage having a DC voltage amplitude. The motor driver is rotatable with the secondary winding and the demodulator circuit and controllably supplies motor current. The motor receives the motor current and rotates at a rotational speed.

A contactless power supply and motor control system includes a pulse width modulator, a rotary transformer, a demodulator circuit, a motor driver, and a motor. The pulse width modulator supplies a first pulse width modulated (PWM) signal that has a duty cycle and a first amplitude. The rotary transformer receives the PWM signal. The secondary winding is rotatable relative to the primary winding and supplies a second PWM signal having the duty cycle and a second amplitude. The demodulator circuit is rotatable with the secondary winding and supplies a demodulated direct current (DC) voltage having a DC voltage amplitude. The motor driver is rotatable with the secondary winding and the demodulator circuit and controllably supplies motor current. The motor receives the motor current and rotates at a rotational speed.

A fan control circuit with temperature compensation includes an on-off unit and a speed adjustment unit. When determining that a loading is greater than or equal to an adjustable start threshold according to a load signal, the on-off unit controls the fan entering a working mode. In the working mode and determining that the loading is less than a speed-adjusting threshold, the on-off unit maintains a speed value of the fan at a first fixed speed. When determining the loading is greater than or equal to the speed-adjusting threshold, the speed adjustment unit adjusts the speed value according to the loading. The speed adjustment unit generates a speed displacement according to a temperature signal to compensate the speed value.

A motor drive system includes a converter configured to convert power between AC power in a power source and DC power in a DC link, an inverter for drive configured to convert power between the DC power and AC power in a servomotor for drive, a motor control unit for drive configured to control the servomotor for drive, a power storage device configured to store the DC power from the DC link or supplies the DC power to the DC link, and a determination unit configured to determine whether the holding energy of the power storage device is lower than a threshold for energy shortage determination, wherein when the holding energy is lower than the threshold for energy shortage determination, the motor control unit for drive controls the servomotor for drive by setting an additional standby period in which the servomotor for drive is inactive in a predetermined operation pattern.