There is provided a printer including a motor configured to convey a medium and a processor configured to control the motor. The processor acquires a signal corresponding to a counterelectromotive force of the motor and performs predetermined processing based on the acquired signal.

A motor control system has a computing device and a motor controller. The computing device receives user demands through a GUI, and provides a preset speed table based on the user demands. The preset speed table has a plurality of fixed values of a duty cycle of a pulse width modulation signal and a plurality of preset values of a preset motor speed corresponding to the plurality of fixed values of the duty cycle of the pulse width modulation signal. The motor controller provides the pulse width modulation signal to drive a motor based on the preset speed table.

Various embodiments of the present technology comprise a method and apparatus for rotation detection of a brushed DC motor. The method and apparatus may detect switching of the commutators and utilize signals indicative of switching to determine speed and/or rotation information of the motor. In one embodiment, the apparatus comprises an ADC, a difference circuit, an absolute value circuit, and a comparator connected in series with each other.

A power conversion unit may include two or more power modules for providing high-voltage direct current power to electrical loads, such as one or more propulsion motors aboard an aerial vehicle. Each of the power modules may be controlled by hysteresis, and may include one or more pairs of transistors that are switched by a gate driver with respect to differences between a reference current and a sensed current passing through a boost inductor. The number, size and shape of the power modules may be selected to accommodate the electrical loads, and may be switched on or off, as necessary. The power conversion unit may feature at least one more power module than is required to meet all anticipated electrical loads, thereby ensuring that the power conversion unit may continue to provide power even in the event that one of the power modules experiences a fault of any kind.

Various embodiments of the present technology comprise a method and apparatus for rotation detection of a brushed DC motor. The method and apparatus may detect switching of the commutators and utilize signals indicative of switching to determine speed and/or rotation information of the motor. In one embodiment, the apparatus comprises an ADC, a difference circuit, an absolute value circuit, and a comparator connected in series with each other.

The present application provides a servo motor drive circuit and a 3D printing apparatus, a motion controller is configured to send a drive enable signal to the timer; a pulse period providing unit is configured to send a pulse period value to the timer and the first comparing unit at beginning of each pulse period; the timer is configured to perform initialization in response to the received pulse period value during enabling of the drive enable signal, perform cyclic timing by taking the pulse period value as a timing period, and send a timing duration to the first comparing unit; and the first comparing unit is configured to acquire current level information that satisfies a preset duty ratio according to the preset duty ratio, the pulse period value, and the timing duration, and send a drive signal to a servo motor according to the current level information.

A motor unit includes a motor, a controller that outputs a pulse signal, a driver that supplies a drive current to the motor based on the pulse signal, and a detector that determines an actual rotation number of the motor. The controller includes calculators that calculate control values of a rotation number of the motor, and control stages. The controller also includes a pulse generator that selects one of the control values calculated by the calculators to generate the pulse signal based on the control value selected, at each of the control stages.

A method for controlling a brushless direct current (BLDC) motor is disclosed. The method includes: receiving a constant current; comparing the constant current to a reference current; based on the comparison revealing that the constant current is smaller than the reference current, providing a first speed command to the rotational speed control unit to increase a speed of the BLDC motor; based on the comparison revealing that the constant current is larger than the reference current, providing a second speed command to the rotational speed control unit to decrease a speed of the BLDC motor; based on the comparison revealing that the constant current is the same as the reference current, providing a third speed command to the rotational speed control unit to maintain a speed of the BLDC motor; and controlling, by the rotational speed control unit, a speed of the BLDC motor.

A motor controller includes a motor drive circuit, a noise cancellation circuit, and a control unit. The motor drive circuit supplies electric power to an electric motor. The noise cancellation circuit includes an RLC circuit, a switch element, and a pull-down resistor. One end of the RLC circuit is electrically connected to a positive terminal of a power supply via the switch element, and the other end of the RLC circuit is electrically connected to a frame ground. A connection point between the RLC circuit and the switch element is electrically connected to a negative terminal of the power supply via the pull-down resistor. The control unit turns ON the switch element for a predetermined time at falling timings of phase voltages output from the motor drive circuit.

A method of controlling a DC motor that includes the step of providing a pulse-width modulation (PWM) signal to the DC motor. The PWM signal provides a voltage to operate the DC motor. The method also includes the steps of measuring a voltage generated by the DC motor when the PWM signal is off. In more particular embodiments, the method includes measuring a current being supplied to the DC motor when the PWM signal is off. The method may further require determining a motor speed of the DC motor based on the measured voltage. The method further includes controlling the DC motor to maintain a relatively constant motor speed with varying loads on the DC motor.