Patent ID: 7054772
Filing Date: 2006-05-30
Classification: F02D,F02M,G01R,H01F

Abstract:
1. A method for compensating for variation in electrical resistance in a solenoid coil during pulse-width cyclic operation thereof between energized and de-energized states, comprising the steps of: a) providing means for determining when said coil is in said de-energized state; b) passing an electrical current of known amperage through said coil when said coil is in said de-energized state; c) measuring voltage drop across said coil during said passing of said current; d) calculating said electrical resistance from said amperage and said voltage drop, using Ohm's Law; e) selecting a nominal resistance for said coil; f) comparing said calculated electrical resistance to said nominal resistance to determine a resistance deviation from nominal; and g) adjusting said pulse width operation to change the respective lengths of said energized and de-energized states to compensate for said resistance deviation.