A fan driving circuit includes a primary winding, an activating capacitor, a control circuit, a switch circuit and a secondary winding. The primary winding and the activating capacitor are electrically coupled to an external power source. The control circuit generates a control signal. The switch circuit is electrically coupled to the first winding. The switch circuit is also electrically coupled to the activating capacitor. The switch circuit has at least one control terminal electrically coupled to the control circuit for receiving the control signal. The secondary winding is electrically coupled to the switch circuit. The secondary winding is electrically coupled to the switch circuit. The secondary winding electromagnetically drives a fan according to a flowing direction of its driving current. The switch circuit conducts the secondary winding's driving current's flowing direction based on the control signal's voltage level.

An electric tool includes a drive structure, a motor, a driver circuit, and a controller. The controller is configured to output a first control signal to control the motor to drive the drive structure to operate in a first operation mode for a preset period of time in response to receiving a start instruction. After the preset period of time, the controller will output a second control signal to control the motor to drive the drive structure to operate in a second operation mode to a preset state. The first operation mode and the second operation mode are two opposite operation modes.

An electric tool includes a drive structure, a motor, a driver circuit, and a controller. The controller is configured to output a first control signal to control the motor to drive the drive structure to operate in a first operation mode for a preset period of time in response to receiving a start instruction. After the preset period of time, the controller will output a second control signal to control the motor to drive the drive structure to operate in a second operation mode to a preset state. The first operation mode and the second operation mode are two opposite operation modes.

Technical solutions are described for controlling operation of a motor using a controller to: energize the motor to rotate driveshaft and a worm; drive a worm gear by the worm; stop the motor from rotating the driveshaft in response to the worm gear rotating to a given one of a plurality of first stop positions; and change the given one of the first stop positions to another one of the first stop positions. A method for controlling a machine comprises: rotating a driveshaft by a motor; driving a worm gear by a worm to cause the worm gear to rotate; stopping the motor from rotating the driveshaft in response to the worm gear rotating to a given one of a plurality of first stop positions; and changing the given one of the first stop positions to another one of the first stop positions.

Technical solutions are described for controlling operation of a motor using a controller to: energize the motor to rotate driveshaft and a worm; drive a worm gear by the worm; stop the motor from rotating the driveshaft in response to the worm gear rotating to a given one of a plurality of first stop positions; and change the given one of the first stop positions to another one of the first stop positions. A method for controlling a machine comprises: rotating a driveshaft by a motor; driving a worm gear by a worm to cause the worm gear to rotate; stopping the motor from rotating the driveshaft in response to the worm gear rotating to a given one of a plurality of first stop positions; and changing the given one of the first stop positions to another one of the first stop positions.

A motor control apparatus includes a detection unit configured to detect an actual rotation position of a motor, a control unit configured to provide position feedback control on the motor so that the detected actual rotation position sequentially approaches a plurality of target rotation positions, and a processing unit configured to perform, before the position feedback control starts, processing to make an initial position deviation fall within a predetermined range, the initial position deviation being a difference between the actual rotation position and a first target rotation position of the plurality of target rotation positions.

To achieve a size reduction by on-off controlling non-contact switching devices with a microcomputer. When a three-phase alternating-current electric motor is to be used, lead wires of the three-phase alternating-current electric motor are connected to output terminals of a control board. When a single-phase alternating-current electric motor is to be used, two supply terminals of the control board are electrically connected together through a first connecting member, and one end of the first connecting member is defined as a single-phase alternating-current power supply terminal. A second connecting member is connected to a supply terminal, and one end of the second connecting member is defined as a single-phase alternating-current power supply terminal. A main winding of the single-phase alternating-current electric motor is connected to the output terminals, and an auxiliary winding is connected to the output terminal and the second connecting member.

A motor driver for driving a rotor of a single coil motor in a clockwise or counterclockwise rotation direction concerning a stator of the single coil motor is adapted for generating a position signal which is representative for the angular position of the rotor regarding the stator and comprises a controller which comprises a direction input to define the rotation direction of the rotor, and which is adapted for generating a driving signal for rotating the rotor in the defined rotation direction, wherein the driving signal is based on the position signal and is based on a signal indicative for an electrical lead angle wherein the signal indicative for the electrical lead angle is set such that the total lead angle is positive in both rotation directions of the rotor.

A motor driver for driving a rotor of a single coil motor in a clockwise or counterclockwise rotation direction concerning a stator of the single coil motor is adapted for generating a position signal which is representative for the angular position of the rotor regarding the stator and comprises a controller which comprises a direction input to define the rotation direction of the rotor, and which is adapted for generating a driving signal for rotating the rotor in the defined rotation direction, wherein the driving signal is based on the position signal and is based on a signal indicative for an electrical lead angle wherein the signal indicative for the electrical lead angle is set such that the total lead angle is positive in both rotation directions of the rotor.

There are described herein methods and systems for operating an electric motor of a watercraft. In one method, the electric motor of the watercraft is controlled based on commands received from an accelerator of the watercraft, a sensor signal is received from at least one sensor of the watercraft while the electric motor is in operation, the sensor signal indicative of an undesirable condition of a water intake of the watercraft, and a change is effected to the controlling of the electric motor in response to receiving the sensor signal.