Abstract: A power tool having an electronically commutated DC motor capable of providing various operating modes ranging from a maximum efficiency operating mode to a maximum power operating mode. The motor has a rotor having permanent magnets mounted in recesses in a back iron of the rotor. In one embodiment the motor has three phase windings, each having at least a pair of coils. The phase windings are connected in either a delta or a wye configuration via electromechanical or electronic switching components, or a combination of both, by a controller within the tool. The coils in each phase winding can also be switched between series and parallel configurations to configure the motor to provide its various operating modes. In one embodiment a dual wound motor is disclosed that has its phase coils dynamically or statically switchable between series and parallel configurations.

Abstract: A power tool in accordance with an embodiment of the invention has a motor driving a member, a switch coupled across windings of the motor that dynamically brakes the motor, and a mechanical brake that brakes speed of the member. In an aspect, the combined dynamic and mechanical braking brakes speed of the member to a desired speed in no more than about two second. In an aspect, the motor is an electronically commutated motor and the power tool includes a controller that electronically commutates the motor by switching switches that switch power to the motor in an electronic commutation sequence and switches the switches to electronically brake the motor.

Abstract: A power tool having an electronically commutated DC motor capable of providing various operating modes ranging from a maximum efficiency operating mode to a maximum power operating mode. The motor has a rotor having permanent magnets mounted in recesses in a back iron of the rotor. In one embodiment the motor has three phase windings, each having at least a pair of coils. The phase windings are connected in either a delta or a wye configuration via electromechancial or electronic switching components, or a combination of both, by a controller within the tool. The coils in each phase winding can also be switched between series and parallel configurations to configure the motor to provide its various operating modes. In one embodiment a dual wound motor is disclosed that has its phase coils dynamically or statically switchable between series and parallel configurations.

Abstract: A hand held orbital sander has a housing having an electronically commutated motor disposed therein and an orbit mechanism disposed beneath the housing. A motor controller is coupled to the motor. The motor controller changes the speed of at which it runs the motor from an idle speed to a sanding speed upon the motor speed dropping from idle speed to an idle speed threshold value and changes the speed at which it runs the motor from sanding speed to idle speed upon the motor speed increasing from sanding speed to a sanding speed threshold value. The sander may have a mechanical brake that brakes the orbit mechanism and the motor controller also dynamically brakes the motor.

Abstract: A charger including a power supply connectable to an outside power source, first and second battery power sources connected to the power supply for providing power to a battery pack, and a controller connected to the first and second battery power sources for controlling the first and second battery power sources. The first and second battery power sources are preferably connected in parallel to the battery.

Abstract: A control system is provided for use in a power tool. The control system includes: a rotational rate sensor having a resonating mass and a controller electrically connected to the rotational rate sensor. The rotational rate sensor detects lateral displacement of the resonating mass and generates a signal indicative of the detected lateral displacement, such that the lateral displacement is directly proportional to a rotational speed at which the power tool rotates about an axis of the rotary shaft. Based on the generated signal, the controller initiates a protective operation to avoid further undesirable rotation of the power tool. The control scheme employed by the power tool may initiate different protective operations for different tool conditions.

Abstract: A power tool is a “low profile” power tool, that is the overall height of the power tool is sufficiently small that a user can grasp the top of the power tool with the user's hand and the hand will be positioned relative close to the bottom of the power tool compared with existing power tools. The low profile power tool uses a low profile motor having a diameter to lamination height ratio of at least 2:1. In an aspect of the invention, the motor is an electronically commutated “pancake” style motor. In an aspect of the invention, the power tool is a random orbital sander or an orbital sander having a motor that provides at least 40 watts of power. In an aspect of the invention, the sander has a mechanical brake that brakes the orbital mechanism and the motor is dynamically braked.

Abstract: A hand held orbital sander has a housing having an electronically commutated motor disposed therein and an orbit mechanism disposed beneath the housing. A motor controller is coupled to the motor. The motor controller changes the speed of at which it runs the motor from an idle speed to a sanding speed upon the motor speed dropping from idle speed to an idle speed threshold value and changes the speed at which it runs the motor from sanding speed to idle speed upon the motor speed increasing from sanding speed to a sanding speed threshold value. The sander may have a mechanical brake that brakes the orbit mechanism and the motor controller also dynamically brakes the motor.