The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Dec. 30, 1997
Filed:
May. 10, 1996
Gary Chris Fulks, Spring Valley, OH (US);
William Dale Cornwell, Jr, Beavercreek, OH (US);
General Motors Corporation, Detroit, MI (US);
Abstract
A solenoid driver circuit is provided that operates a solenoid in a quiet operation by reducing solenoid armature velocity. A pulse signal and a ramp signal are provided by a frequency generator and a ramp generator, respectively. A frequency switching circuit receives the pulse and ramp signals and responsively provides a time varying pulse signal that has a duty cycle that decreases with time. A dwell circuit allows the frequency switching circuit to control the solenoid for a first time period and then provides an on signal to the solenoid, maintaining the solenoid in the on position. The solenoid driver circuit is particularly suitable for use with solenoid controlled valves.