Patent ID: 7487844
Filing Date: 2009-02-10
Classification: B25B,B25F,H01H,H02P,Y10S

Abstract:
1. A hand power tool having solid state motor control comprising: a moveable member having a reflective surface and the moveable member traversing a distance between a stop position and a full speed position; a biasing member operatively coupled to the moveable member to bias the moveable member toward the stop position; an optical signal generator for generating an optical signal, the optical signal generator being oriented so that the optical signal is directed toward the reflective surface of the moveable member; a speed control signal generator for generating a variable speed control signal that corresponds to a reflection of the generated optical signal reflected by the reflective surface of the moveable member; a microcontroller for generating a pulse width modulated (PWM) signal corresponding to the variable speed control signal; a driver circuit for generating H-bridge driving signals corresponding to the PWM signal; and an H-bridge circuit for selectively coupling a motor to a power source in accordance with the H-bridge driving signals.