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:
Mar. 24, 2009
Filed:
Dec. 04, 2007
Atsuya Mizutani, Obu, JP;
Atsuya Mizutani, Obu, JP;
Denso Corporation, Kariya, Aichi-Pref., JP;
Abstract
An ignition system for an internal-combustion engine includes an ignition coil and an ignition control circuit. The ignition coil includes a primary coil and a secondary coil. The ignition control circuit includes a capacitor. The ignition control circuit employs a capacitor discharged ignition method, whereby the ignition control circuit is configured such that electrical charge, with which the capacitor is charged, is discharged into the primary coil to drive the ignition coil. A coupling coefficient, which indicates a degree of magnetic coupling between the primary coil and the secondary coil, is set in a range of 0.9 to 0.97. k, which is the coupling coefficient, is provided using a formula k=(1−L'/L), wherein Lis an inductance of the primary coil and L′ is an inductance of the primary coil when the secondary coil is short-circuited.