Switch for accumulator powered, electric motor driven tool

摘要

The switch has a housing, a contact system(s) (14, 15) operated by an actuator (3), control electronic system for electric motor r.p.m. regulation, an electric and/or electronic component, eg. a power semiconductor, energised by the control electronic, for the motor control. There is a freewheeling diode (39) for reduction of energy stored in the motor, due to inductivity, and a cooler (36) in thermal contact with the power semiconductor. The latter has a casing and is pref. located outside the switch housing. The semiconductor casing is, at least partly, in thermal and/or electric contact with the cooler part outside the switch housing.