Ernest B Long

US Patent:

RE313912, Sep 20, 1983

Filed:

Jan 14, 1976

Appl. No.:

5/649005

Inventors:

William F. Davis - Tempe AZ
Ronald W. Russell - Sunnyvale CA
Thomas M. Frederiksen - San Jose CA
Ernest L. Long - San Jose CA

Assignee:

Motorola, Inc. - DE

International Classification:

F02D 500
H01F 718

US Classification:

361154

Abstract:

A system for energizing an inductive load includes a voltage regulator for providing a constant voltage across the load until the current builds up to a particular value, and a current regulator which then takes over to provide a constant holding current at a lower value. The voltage regulator may include a closed loop for holding the voltage across the inductive load constant or may respond to a regulated voltage value to control a power stage for providing a constant voltage. The voltage across a sensing resistor in the power stage controls the crossover from the voltage regulation mode, to the current regulation mode and the current regulator automatically resets the reference to control the power stage to provide a constant current of a lower value through the load. The system can be used to supply current to coils of injector valves in a fuel injection system, and may include two power stages for supplying current to two banks of coils. The regulator system is switched from one power stage to the other during successive 180. degree.