The present teaching relates to a magnetic sensor comprising an input port to be connected to an external power supply, a magnetic field detecting circuit configured to generate a magnet detection signal, an output control circuit configured to control operation of the magnetic sensor in response to the magnet detection signal, and an output port. The magnetic field detecting circuit includes a magnetic sensing element configured to detect an external magnetic field and output a detection signal, a signal processing element configured to amplify the detection signal and removing interference from the detection signal to generate processed detection signal, and an analog-digital conversion element configured to convert the processed detection signal into a magnet detection signal, and the output control circuit is configured to control the magnetic sensor to operate in at least one of a first state and a second state responsive to at least the magnet detection signal.

A fan motor controller comprises a pulse width modulation signal, a switch circuit, a control unit, and a frequency judging unit. The switch circuit is coupled to a fan motor for supplying a driving current to the fan motor. The control unit generates a control signal to the switch circuit, so as to control the switch circuit. The frequency judging unit receives the pulse width modulation signal for generating a judging signal to the control unit. The pulse width modulation signal is configured to adjust a speed of a fan. The pulse width modulation signal has a frequency. Based on the frequency and a judgment rule, the fan motor controller is configured to attain the function of switching between the forward direction and the reverse direction of the fan.

A long-distance speed control system for a brushless DC motor of a fan is provided. The long-distance speed control system includes a switch connected with a mains power supply, a switch circuit, a voltage detection module, a power cord, a processing unit, and a drive unit, which can control the multi-stage rotational speed of the motor. In the field of brushless DC motors for fans, there is no need to use analog-to-digital conversion chips between the mains power supply and the processor, having the advantages of low cost, environmental protection, and reduction of waste of earth resources. Besides, the switch, the switch circuit and the power cord can withstand the mains power supply, having the advantages of less signal attenuation and long-distance transmission.

A motor control system for a closure latch assembly is provided and includes a power release motor operatively coupled to a power release gear of the closure latch assembly. A plurality of relays are coupled between one of a first motor terminal and a second motor terminal and one of a voltage supply and an electrical ground to provide one of a first motor current flow to drive the power release motor in a first direction and a second motor current flow to drive the power release motor in a second direction. An electronic control unit is coupled to the plurality of relays and configured to command the plurality of relays to provide the first motor current flow in one of a power release mode and a release mode and the second motor current flow in one of a reset mode and an unlock mode.

A motor drive system includes a rectifier circuit, a controller, a modulator circuit and a direct current (DC) motor. The rectifier circuit is configured to convert an alternating current (AC) voltage to a DC voltage. The controller is configured to output a control signal. The modulator circuit includes a pulse generation module, a feedback determination module, a pulse modulation module and a driving module, and is configured to generate a modulated DC driving signal based on the DC voltage and the control signal generated by the rectifier circuit and the controller. The DC motor is configured to operate in accordance with the modulated DC driving signal generated by the modulator circuit.

A power tool and a safety control circuit module and a safety control method thereof are provided. The power tool includes a power supply device, a control processing device, a safety control circuit module, and a power output device. The control processing device is electrically connected with the power supply device. The safety control circuit module includes a first switch control circuit, a second switch control circuit, a third switch control circuit, a first resistor, and a first diode. The power output device includes a first power connection terminal and a second power connection terminal. Before switch units of the control circuits are controlled, the control processing device detects whether the switch unit has failed, so as to increase safety.

A fluid sprayer includes a housing, a pump, a nozzle, a high voltage direct current (HVDC) brushed electric motor that drives the pump, and a motor controller electrically connected to the motor. The motor controller drives the motor with a high speed pulse width modulated (PWM) drive signal that switches current through the motor on and off. The motor controller varies the PWM signal as a function of a spray setting input and sensed current through the motor.

A power tool includes a multi-phase BLDC motor, a plurality of switches, an input unit, and a controller. For each phase, the controller operates to vary power output to the motor between a first power and a second power by varying a duty cycle of a PWM signal from 0% to 100% while keeping a conduction band (CB) of corresponding motor switches and/or an advance angle (AA) at a predetermined value when the input unit moves between a first position and a predetermined position between the first and a second position. For each phase, the controller operates to increase the power output by the motor to greater than the second power by increasing the CB/AA to greater than the predetermined value while keeping the duty cycle of the PWM signal at 100% when the input unit moves between the predetermined position and the second position.

A long-distance speed control system for a brushless DC motor of a fan is provided. The long-distance speed control system includes a switch connected with a mains power supply, a switch circuit, a voltage detection module, a power cord, a processing unit, and a drive unit, which can control the multi-stage rotational speed of the motor. In the field of brushless DC motors for fans, there is no need to use analog-to-digital conversion chips between the mains power supply and the processor, having the advantages of low cost, environmental protection, and reduction of waste of earth resources. Besides, the switch, the switch circuit and the power cord can withstand the mains power supply, having the advantages of less signal attenuation and long-distance transmission.

A motor control system, in some embodiments, comprises: a voltage divider circuit having an output node, a voltage on said output node representing a desired motor rotation direction; control logic configured to receive an indication of said voltage; and a motor controller coupled to the control logic, wherein, if said indication of the voltage on the output node falls outside of a predetermined range, the control logic is configured to issue a motor stop signal to the motor controller indicating that at least one resistor of the voltage divider circuit is defective or is missing from the voltage divider circuit.