A motor assembly including a motor and a control circuit board. The motor includes a housing, a stator assembly, a rotating shaft, and a rotor assembly. The control circuit board includes a first electric wire, a second electric wire, a detection wire, a ground wire, a power supply circuit, a control circuit, and a detection circuit. The first electric wire and the second electric wire are connected to the commercial AC electric supply, and the detection wire detects whether or not a load connected to the motor is electrified. The first electric wire and the second electric wire are connected to the input terminals of the power supply circuit. The detection circuit is disposed between the detection wire and the ground wire. The detection circuit transmits a detection signal to the control circuit, and the control circuit controls the motor to rotate at various rotation speeds.

To provide a power tool configured to stably rotate an end tool. The provided power tool includes a brushless motor including a rotor configured to rotate; a rectifier circuit configured to rectify an AC voltage; a smoothing capacitor configured to smooth the AC voltage rectified by the rectifier circuit to a pulsating voltage; an inverter circuit configured to perform switching operations to output the pulsating voltage to the brushless motor; a deceleration mechanism including: a driving portion at a rotor side, a driven portion configured to transmit a rotating force to an end tool side, and an elastic member configured to transmit a rotational force of the driving portion to the driven portion, the deceleration mechanism configured to decelerate a speed of a rotation of the rotor and configured to transmit the rotation to an end tool.

A motor assembly including a motor and a control circuit board. The motor includes a housing, a stator assembly, a rotating shaft, and a rotor assembly. The control circuit board includes a first electric wire, a second electric wire, a detection wire, a ground wire, a power supply circuit, a control circuit, and a detection circuit. The first electric wire and the second electric wire are connected to the commercial AC electric supply, and the detection wire detects whether or not a load connected to the motor is electrified. The first electric wire and the second electric wire are connected to the input terminals of the power supply circuit. The detection circuit is disposed between the detection wire and the ground wire. The detection circuit transmits a detection signal to the control circuit, and the control circuit controls the motor to rotate at various rotation speeds.

A motor assembly including a motor and a control circuit board. The motor includes a housing, a stator assembly, a rotating shaft, and a rotor assembly. The control circuit board includes a first electric wire, a second electric wire, a detection wire, a ground wire, a power supply circuit, a control circuit, and a detection circuit. The first electric wire and the second electric wire are connected to the commercial AC electric supply, and the detection wire detects whether or not a load connected to the motor is electrified. The first electric wire and the second electric wire are connected to the input terminals of the power supply circuit. The detection circuit is disposed between the detection wire and the ground wire. The detection circuit transmits a detection signal to the control circuit, and the control circuit controls the motor to rotate at various rotation speeds.

To provide a power tool configured to stably rotate an end tool. The provided power tool includes a brushless motor including a rotor configured to rotate; a rectifier circuit configured to rectify an AC voltage; a smoothing capacitor configured to smooth the AC voltage rectified by the rectifier circuit to a pulsating voltage; an inverter circuit configured to perform switching operations to output the pulsating voltage to the brushless motor; a deceleration mechanism including: a driving portion at a rotor side, a driven portion configured to transmit a rotating force to an end tool side, and an elastic member configured to transmit a rotational force of the driving portion to the driven portion, the deceleration mechanism configured to decelerate a speed of a rotation of the rotor and configured to transmit the rotation to an end tool.