ELECTRIC TOOL Russian patent published in 2018 - IPC B25F5/00 H02P27/08 

FIELD: electricity.

SUBSTANCE: invention relates to electric tools. Electric tool comprises a motor configured to be controlled by pulse width modulation through semiconductor switching element using a power supply, transmission mechanism configured to transmit rotation of the motor to an end tool, and a controller. Controller provides control of motor rotation through the duty ratio of a pulse width modulation signal. If an extension cord is connected between the power cord and the external power source and the power from the external power source is supplied through the power cord and extension cord, the controller provides, after a predetermined time after the engine start, engine control with setting of the duty factor to a value, greater than the value set in the case of power supply from an external power source only through the power cord.

EFFECT: preventing decrease in the motor torque during voltage fluctuations.

12 cl, 10 dwg