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:
Oct. 11, 2005
Filed:
Jun. 11, 2003
Guoming G. Zhu, Novi, MI (US);
Bruce Wang, Troy, MI (US);
Kenneth L. Gould, Fayetteville, GA (US);
Visteon Global Technologies, Inc., Van Buren Township, MI (US);
Abstract
A circuit for measuring ionization current in a combustion chamber of an internal combustion engine including an ignition coil, having a primary winding and a secondary winding, and an ignition plug. The ignition plug ignites an air/fuel mixture in the combustion chamber and produces an ignition current in response to ignition voltage from the ignition coil. A capacitor, charged by the ignition coil, provides a bias voltage producing an ionization current after ignition of the air/fuel mixture in the combustion chamber. A current mirror circuit produces an isolated current signal proportional to the ionization current. In the present invention, the ignition current and the ionization current flow in the same direction through the secondary winding of the ignition coil. The charged capacitor operates as a power source and, thus, the ignition current flows from the charged capacitor through the current mirror circuit and the ignition coil to the ignition plug.