Patent ID: 7342369
Filing Date: 2008-03-11
Classification: H02P

Abstract:
1. A system for monitoring operations of an electric motor, the system comprising: a bi-directional current sensor in communication with the electric motor and configured for bi-directional sensing of current circulating through the electric motor, the bi-direction sensor configured to sense current flowing in a primary direction and secondary direction, the primary direction associated with current flow from an external power source to the electric motor and the secondary direction associated with internal current flow resulting from rotation of the electric motor when the external power source is disconnected from the motor; a controller in communication with the current sensor to determine an angular position of the electric motor as a function of the current circulating through the electric motor, regardless of whether the current is flowing in the primary or secondary directions; and a direction detector in communication with the bi-direction current sensor for determining a direction of an element moved by the electric motor, the direction detector determining the direction of movement as function of the current flowing in the primary and secondary directions.