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:
Sep. 19, 2000
Filed:
Sep. 22, 1998
Danny O Wright, Cobb's Creek, VA (US);
Siemens Automotive Corporation, Auburn Hills, MI (US);
Abstract
A fuel injector apparatus includes an electromagnetic fuel injector having a housing and a magnetic circuit in the housing. The magnetic circuit includes a first coil having a certain resistance to generate a peak current and a second coil having a resistance greater than the certain resistance to generate a hold current. Circuit structure is disposed in the housing and is electrically coupled with the coils to selectively excite the coils. The circuit structure includes switch structure to transition the peak current to the hold current based on a preset threshold. In a preferred embodiment of the invention, the switch structure includes an RC circuit and a comparator which sets a threshold voltage. A time constant of the RC circuit is provided to be an analog model of an inductance and resistance time constant of the fuel injector such that when a voltage of a capacitor of the RC circuit exceeds the threshold voltage, the peak current is transitioned to the hold current.