Systems and methods of operating power tools. The method includes receiving a command to start a recording mode at a first electronic processor of a first power tool, and receiving at the first electronic processor, a measured parameter from a sensor of the first power tool while a first motor of the first power tool is operating. The method also includes generating a recorded motor parameter by recording the measured parameter, on a first memory of the first power tool, when the first power tool operates in the recording mode, and transmitting, with a first transceiver of the first power tool, the recorded motor parameter. The method further includes receiving the recorded motor parameter at an external device, transmitting the recorded motor parameter to a second power tool via the external device, and receiving the recorded motor parameter via a second transceiver of the second power tool.

A determination method and apparatus for a brushless direct current counter-electromotive force zero crossing point threshold and a storage medium, the method includes detecting counter-electromotive force zero crossing point time intervals of two adjacent sectors of a brushless direct current electric motor to obtain at least two first time intervals; utilizing the obtained at least two first time intervals to determine errors of a counter-electromotive force zero crossing point; converging the determined errors of the counter-electromotive force zero crossing point to obtain a counter-electromotive force zero crossing point threshold correction increment; and utilizing the obtained counter-electromotive force zero crossing point threshold correction increment to determine a counter-electromotive force zero crossing point threshold.

A wristwatch includes a first motor that drives a first hour hand, a first control circuit electrically coupled to the first motor and outputting a first motor drive signal, and a second control circuit electrically coupled to the first motor and outputting a second motor drive signal. When the first control circuit outputs the first motor drive signal, the second control circuit is in a high impedance state to the input of the first motor drive signal, and when the second control circuit outputs the second motor drive signal, the first control circuit is in the high impedance state to the input of the second motor drive signal.

A geared motor is provided, including an electric motor, a transmission, a drive shaft and a switching device arranged on the drive shaft. The switching device includes a single housing that is distinct and separate from an electric motor housing and a transmission housing. The switching device also includes a contactless, absolute position-measuring device and an evaluation unit, each provided within the single housing, a gear wheel coupled to the drive shaft, and an output unit. The switching device is coupled to the position-measuring device by a pinion, which rotates about the same rotational axis as the drive shaft.

A geared motor is provided, including an electric motor, a transmission, a drive shaft and a switching device arranged on the drive shaft. The switching device includes a single housing that is distinct and separate from an electric motor housing and a transmission housing. The switching device also includes a contactless, absolute position-measuring device and an evaluation unit, each provided within the single housing, a gear wheel coupled to the drive shaft, and an output unit. The switching device is coupled to the position-measuring device by a pinion, which rotates about the same rotational axis as the drive shaft.

In response to a measured value of temperature of a stator by a thermometer exceeding a first temperature threshold, an overheat signal may be output to a rotor of a rotary connector via a communication device. In response to the measured value of the temperature exceeding a second temperature threshold higher than the first temperature threshold, power supply to a transmission coil that transmits power to a receiving coil of the rotor in a non-contact manner is stopped. In response to the overheat signal being received or a measured value of temperature of the rotor by a thermometer exceeding a third temperature threshold, a limit signal for limiting current flowing through a load circuit is output. In response to the measured value of the temperature by the thermometer exceeding a fourth temperature threshold higher than the third temperature threshold, output of power received from the stator is stopped.

A motor current controlling circuit having a voltage detection mechanism is provided. A first terminal of a first low-side transistor is connected to a second terminal of a first high-side transistor. A node between the first terminal of the first low-side transistor and the second terminal of the first high-side transistor is connected to a first terminal of a motor. A first terminal of a second low-side transistor is connected to a second terminal of a second high-side transistor. A zero current detector circuit detects a voltage of the node and determines whether or not a current flowing through the motor is equal to a zero value to output a zero current detected signal according to the detected voltage. A controller circuit controls a driver circuit to turn on or off the high-side transistors and the low-side transistors according to the zero current detected signal.

A motor current controlling circuit having a voltage detection mechanism is provided. A first terminal of a first low-side transistor is connected to a second terminal of a first high-side transistor. A node between the first terminal of the first low-side transistor and the second terminal of the first high-side transistor is connected to a first terminal of a motor. A first terminal of a second low-side transistor is connected to a second terminal of a second high-side transistor. A zero current detector circuit detects a voltage of the node and determines whether or not a current flowing through the motor is equal to a zero value to output a zero current detected signal according to the detected voltage. A controller circuit controls a driver circuit to turn on or off the high-side transistors and the low-side transistors according to the zero current detected signal.

A motor control device includes a motor, a drive circuit, a current detection unit, and a control unit. The motor has a plurality of phases of motor windings. The drive circuit is provided on a low potential side of the motor windings. The current detection unit has current detection resistors corresponding to each phase, and is provided on a low potential side of the drive circuit. The control unit includes an actuator control unit and an abnormality diagnosis unit. The abnormality diagnosis unit determines that the current detection unit is abnormal, when a difference between a maximum current, which is a maximum value of the phase current when a same duty ratio is commanded to each phase, and a minimum current, which is a minimum value of the phase current when a same duty ratio is commanded to each phase, is equal to or greater than an abnormality determination threshold.

Provided is a motor control device in which, with a position detection signal corresponding to a phase with a first reference Hall edge forming a first Hall stage, which is a minimum counter value, defined as a first reference position detection signal, and with a position detection signal corresponding to a phase with a second reference Hall edge forming a second Hall stage, which is an intermediate value, defined as a second reference position detection signal, for a first detection error with the first reference position detection signal used as a reference and a second detection error with the second reference position detection signal used as a reference, a correction coefficient calculated from one of the first and second detection errors is selected and set based on whether the first and second detection errors include a negative value.