Patent ID: 9257925
Filing Date: 2016-02-09
CPC Classification: A01D,B25F,H02P

Claim Text:
1. A power tool, comprising: a driven element, an electric motor coupled to the driven element so as to drive the driven element, an electric power source electrically coupled to the motor so as to supply electric current to the motor and a control circuit arranged to control the supply of electric current to the motor from the power source, and a current sensor operable to output a current signal indicative of the current flowing through the motor; in which the control circuit has a high speed mode and a low speed mode, the control circuit being arranged so that: when it is in the high speed mode, the control circuit supplies electric current to the motor so as to attempt to drive the driven element at a first desired speed; when it is in the low speed mode, the control circuit supplies electric current to the motor so as to attempt to drive the driven element at a second desired speed which is lower than the first desired speed; and the control circuit switches between the high speed mode and the low speed mode dependent on the current signal, wherein the control circuit is configured to switch to the high speed mode when the current signal indicates increasing current and to switch to the low speed mode when the current signal indicates lessening current.