Chervon (Hk) Limited

Nanjing Chervon Industry Co., Ltd.

Chervon Intellectual Property Limited

Pingbo Shi

Dezhong Yang

Lei Liu

Fangjie Nie

Lei Wang

Junya Duan

Qi Zhang

Jifeng Feng

Zheng Geng

Yingdian Xiang

A power tool and a printed circuit board for use therewith. The power tool has an electric motor and a power source. The printed circuit board assembly has a main board having a conductive portion, a semiconductor power device, and a conductor attached to the conductive portion. The conductive portion electrically connects to the semiconductor power device and the conductor electrically connects to the conductive portion. When current is flowing through the printed circuit board, the heat and the voltage loss generated by the printed circuit board can be reduced.

Power tool and circuit board

A battery pack, a method for detecting the battery pack, a charging assembly, and an electric tool are provided for detecting voltage and disconnection of the battery cells. The battery pack may have an output voltage of at least 56V and may include a plurality of series connection units. A voltage detecting module may be utilized for detecting voltage in the battery pack. A battery control module configured to control voltage detecting module may also be employed. The method may involve determining whether the series connection units are disconnected based on rates of voltage change or internal-resistance of the series connection units.

Battery pack, method for detecting battery pack, charging assembly and electric tool

An electric tool has a motor, an implementing member driven by the motor for driving a working element and a controlling circuit for controlling the electric tool. The controlling circuit includes a current detecting module for detecting the current flowing through the motor; a microprocessor for memorizing and storing a current value; an user interface module for an user to select working modes, and the working modes at least comprising a learning mode for recording the current value after the implementing member has driven the working element and a constant torque mode for driving other working elements having the same size based on the recorded current value; and a driving module for driving or stopping the torque output of the motor. The electric tool can achieve the function of electronic clutch so as to drive screws having the same size with substantially the same effect. The present disclosure also discloses a controlling method by using the above controlling circuit.

Electric tool and controlling method thereof

A brushless motor includes a rotor, a plurality of sets of stator windings, a position detection assembly, a MOSFET assembly, an inductance detection module and a main control module that controls them. The position detection assembly has a plurality of detection elements for detecting a position of the rotor and a position detection module for receiving signals fed back from the detection elements with the position detection module being electrically connected to the main control module and feeding back the positional information of the rotor thereto. The main control module alternatively switches between the position detection assembly and the inductance detection module to detect the position of the rotor. When the motor runs at a low speed, the system may effectively judge the position of the rotor to enable the machine to start with a load and, when the motor runs at a high speed, the system may accurately judge the position of the rotor, correctly drive the motor to run, eliminate errors caused by assembly, and prolong the service life of the motor.

Brushless motor and control method thereof

An over-temperature protection circuit for a direct current (DC) electric tool includes a current detecting circuit electrically coupled to a battery pack, a power device control circuit electrically coupled to an electric motor of the DC electric tool and a power device for controlling the power state of the circuit. A computation control circuit controls the power supply of the motor according to the circuit current value detected by the current detecting circuit. When the electric motor is not in a speed control state, the allowable current passing through the over-temperature protection circuit of the DC electric tool cannot exceed a preset first current value. When the electric motor is in the speed control state, the allowable current passing through the over-temperature protection circuit of the DC electric tool cannot exceed a preset second current value less than the first current value.

Over-temperature protection circuit for power devices

A power tool includes a replaceable blade, a fixing device for clamping and securing the blade, a control circuit for controlling a driving device, and a main switch electrically connected to the control circuit. A safety device prevents the blade from moving when the fixing device is opened.

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Nanjing, China

Pingbo Shi