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:
Nov. 17, 1987
Filed:
Apr. 24, 1986
Josef Buchl, Lenting, DE;
Other;
Abstract
A circuit and method for actuation of a gas intake or exhaust valve which is electromagnetically held in its opened and closed positions by an actuator assembly having a ferromagnetic element attractable by actuating solenoids. Control of the holding current flow through the solenoid coil is provided by a relaxation circuit element, and the excitation current is directly monitored and measured. Upon deexcitation of the coil and relaxation circuit-element activation, the decay current is not measured but is instead simulated. The relaxation circuit is supplied with pulsed current during the stationary phase of the valve, the current being measured in the pulse cycle during current supply, and is turned off upon exceeding a ceiling value. After the decay current has reached a threshold value, the current is turned on and permitted to rise momentarily. It is thereafter cycled off and on between an I.sub.1 and I.sub.2 value which is only about 10-20% of I.sub.max, the capture current.