Patent ID: 7701159

Claim:
A brushless motor system, comprising: a brushless motor having a stator that includes motor windings, and a rotor, wherein a first metal housing is associated with said rotor and stator; and an inverter including an inverter circuit inside a second metal housing, for driving said brushless motor through three motor power lines connected to said motor windings; wherein said first metal housing and said second metal housing are electrically connected to ground; said inverter has i) a first wiring for receiving electric power from a first terminal of a direct current power source which has a second terminal electrically connected to ground, and ii) a second wiring that is electrically connected to a ground, for connection to said second terminal of said direct current power source via ground; and a noise return line for returning a noise current is connected between said brushless motor and said inverter, independently of the electrical connection of said first and second metal housings to ground.