Patent ID: 8446120
Filing Date: 2013-05-21
Classification: B25F,H01H,H01R,H02K,H02P

Abstract:
1. A power tool comprising: a tool housing; an electric motor inside the tool housing; a power interface facilitating a connection to a power source; at least four power components configured as an H-bridge to modulate a supply of power from the power interface to the electric motor, the power components being actively-controlled semiconductor switches; a user-actuated input unit configured to output a first signal indicative of a desired power output level to the electric motor and a second signal indicative of a desired direction of current flow to the electric motor; and a control unit configured to receive the first and second input signals from the user-actuated input unit and to control the supply of power to the electric motor using two of said power components with synchronous rectification for pulse-width modulation (PWM) of the supply of power based on the first signal, and to control the direction of current flow to the electric motor using the other two of said power components based on the second signal.