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. 25, 2003
Filed:
Apr. 04, 2002
Hiroshi Yorita, Kariya, JP;
Masatoshi Ikeda, Hazu-gun, JP;
Makoto Toriyama, Chiryu, JP;
Tohru Yoshinaga, Okazaki, JP;
Other;
Abstract
In an engine ignition unit, a transistor and a current detecting resistor are connected to primary and secondary windings of an ignition coil, respectively. The current detecting resistor is used for detecting a current flowing between the opposing electrodes of spark plug. At an ignition by the spark plug, high-frequency square wave signals are generated by an oscillator after an ignition signal is cut off. The square wave signals turn on and off the transistor. By this operation, a battery voltage is intermittently applied to the primary winding and an ion current is measured. A frequency of the square wave signals is set close to a resonant frequency of an ion current path including the spark plug, the secondary winding of the ignition coil and the current detecting resistor.