Power tool with separate motor case compartment

A power tool comprising:

• a housing defining a cavity therein, where the housing includes a motor case portion and a non-motor case portion;
• an electric motor having a drive shaft and mounted within the motor case portion of the housing;
• a motor drive circuit accommodated within the non-motor case portion of the housing and configured to drive the electric motor;
• a partition separating the motor case portion from the non-motor case portion of the housing, where the partition is in form of a pocket with an open end facing the motor case portion;
• a rear bearing for the drive shaft, the rear bearing disposed into the open end of the pocket and supported by an inner surface of the pocket;
• and
• one or more sense magnets affixed to the drive shaft, where the one or more sense magnets are arranged along the drive shaft in between the rear bearing and a closed end of the pocket,
• wherein the motor drive circuit includes:
• a rectifier configured to receive an alternating current from an alternating current (AC) power source and operable to convert the alternating current to a direct current supplied to a DC power bus;
• a switching arrangement having a plurality of motor switches connected electrically between the rectifier and the electric motor, and operates to deliver the direct current from the rectifier to electric motor;
• a link capacitor electrically coupled in parallel with the rectifier and electrically connected between the rectifier and the switching arrangement;
• and
• an auxiliary switch path electrically coupled in parallel with the rectifier and electrically connected between the rectifier and the switching arrangement, wherein the auxiliary switch path includes an auxiliary capacitor in series with a switch, such that the capacitance of the auxiliary capacitor is more than capacitance of the link capacitor.

A power tool comprising:

• an elongated housing defining a cavity therein, where the housing includes a motor case disposed at a front end thereof and a handle portion extending axially along a longitudinal axis of the housing from the motor case to a rear end of the housing;
• an electric motor having a drive shaft and mounted within the motor case, wherein one or more sense magnets are affixed to the drive shaft;
• an output shaft drivably coupled to the drive shaft of the electric motor and extending perpendicular to the drive shaft;
• a wall separating the cavity between the motor case and the handle portion of the housing, wherein the wall is in form of a pocket with an open end facing the motor case portion and the pocket is sized to receive the electric motor;
• one or more position sensors mounted to a position sense board, wherein the position sense board is positioned into a slot formed in the pocket, such that the one or more position sensors are adjacent to the one or more sense magnets and cooperate with the one or more sense magnets to sense rotational motion of the drive shaft;
• and
• a motor drive circuit accommodated within the handle portion of the housing and configured to deliver a direct current from a DC power bus to the electric motor.