A motor starter has a housing, a contactor portion disposed within the housing, a motor protection system disposed within the housing adjacent to the contactor portion in a vertical direction, and an actuation system disposed within the housing. The contactor portion may switch between an open position and a closed position, in which, in the open position, current does not flow through the motor starter and, in the closed position, current is allowed to flow through the motor starter. The motor protection system includes a plurality of components that may move the contactor portion to the open position based on a current flow, in which the actuation system may move the contactor portion between the closed position and the open position in response to receiving an input.

A motor starter has a housing, a contactor portion disposed within the housing, a motor protection system disposed within the housing adjacent to the contactor portion in a vertical direction, and an actuation system disposed within the housing. The contactor portion may switch between an open position and a closed position, in which, in the open position, current does not flow through the motor starter and, in the closed position, current is allowed to flow through the motor starter. The motor protection system includes a plurality of components that may move the contactor portion to the open position based on a current flow, in which the actuation system may move the contactor portion between the closed position and the open position in response to receiving an input.

A fan for use in agriculture which has a BLDC motor which allows for varying the speed of the fan to vary the airflow rate of the fan and vary the efficiency of the fan. A ventilation system for use in a livestock confinement building to maximize a rate of growth of the livestock. A process for maximizing the growth of livestock in a livestock confinement building by controlling the airflow in the livestock confinement building.

A power tool includes a housing, an electric motor, a driver circuit, a speed detection device, and a control device. The driver circuit is electrically connected to the electric motor to drive the electric motor to operate. The speed detection device is configured to acquire a rotational speed of the electric motor. The control device is connected to the speed detection device and the driver circuit and outputs a control signal to the driver circuit to control rotation of the electric motor. The control device is configured to acquire the rotational speed of the electric motor when the electric motor is in a start-up stage, obtain a rotational speed variation of the electric motor within a preset time based on the rotational speed of the electric motor, and turn off the electric motor when the rotational speed variation is less than a rotational speed variation threshold.

A fan for use in agriculture which has a BLDC motor which allows for varying the speed of the fan to vary the airflow rate of the fan and vary the efficiency of the fan. A ventilation system for use in a livestock confinement building to maximize a rate of growth of the livestock. A process for maximizing the growth of livestock in a livestock confinement building by controlling the airflow in the livestock confinement building.

A BLDC motor driver circuit includes: a driving power stage circuit configured to provide a start-up test signal in a start-up mode to excite a BLDC motor, to drive a rotor of the BLDC motor to rotate for a test; a current unidirectional circuit coupled to the BLDC motor at a reverse end for detecting a BEMF, to generate a detection signal at a forward end of the current unidirectional circuit, wherein when a voltage at the reverse end exceeds a voltage at the forward end, the current unidirectional circuit limits the voltage at the forward end not to be higher than a clamp voltage; a biasing circuit for biasing the current unidirectional circuit in a forward operation state and for providing the clamp voltage; and a sensor circuit for generating a sensing signal according to the detection signal to indicate a test rotation state of the BLDC motor.

A BLDC motor driver circuit includes: a driving power stage circuit configured to provide a start-up test signal in a start-up mode to excite a BLDC motor, to drive a rotor of the BLDC motor to rotate for a test; a current unidirectional circuit coupled to the BLDC motor at a reverse end for detecting a BEMF, to generate a detection signal at a forward end of the current unidirectional circuit, wherein when a voltage at the reverse end exceeds a voltage at the forward end, the current unidirectional circuit limits the voltage at the forward end not to be higher than a clamp voltage; a biasing circuit for biasing the current unidirectional circuit in a forward operation state and for providing the clamp voltage; and a sensor circuit for generating a sensing signal according to the detection signal to indicate a test rotation state of the BLDC motor.

The present disclosure a program burning device configured to read or write to a program burning interface. The program burning device includes a microprocessor, a programming drive circuit and an overcurrent protection circuit. The microprocessor outputs a first test signal or a second test signal. The programming drive circuit outputs a high driving voltage or a low driving voltage to the program burning interface. After the programming drive circuit outputs the low driving voltage for a preset time, the programming drive circuit outputs the high driving voltage to make the program burning interface form a high impedance. Afterwards, the overcurrent protection circuit receives the first test signal to trigger the overcurrent protection, and then receives the second test signal to trigger the undercurrent protection. If triggering the overcurrent protection and the undercurrent protection are continuously failed over a preset number of times, the microprocessor determines that current protection is failed.

An electric work machine includes a motor, a first connector, a second connector, an energizing circuit, a manual switch, and a controller. The controller electrically disconnects the first connector from the motor based on a first voltage value below a first threshold at a start of motor rotation. The controller maintains an electrical connection of the first connector to the motor based on the first voltage value below the first threshold and equal to or greater than a second threshold during discharge of the first battery.

An electric work machine includes a motor, a first connector, a second connector, an energizing circuit, a manual switch, and a controller. The controller electrically disconnects the first connector from the motor based on a first voltage value below a first threshold at a start of motor rotation. The controller maintains an electrical connection of the first connector to the motor based on the first voltage value below the first threshold and equal to or greater than a second threshold during discharge of the first battery.