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. 22, 1991
Filed:
Sep. 17, 1990
Hideo Asakura, Toyohashi, JP;
Motokazu Momiyama, Okazaki, JP;
Nippondenso Co., Ltd., Kariya, JP;
Abstract
A contactless ignition apparatus for an internal combustion engine comprises a resin-molded closed magnetic circuit type ignition coil including an iron core constituting a closed magnetic circuit, a primary winding and a secondary winding wound around the iron core, respectively, and mold resin for insulating the primary and secondary winding, a semiconductor switching circuit for interrupting a current flowing to the primary winding, and an ignition plug to which a high voltage generated in the secondary winding upon interruption of the primary current flow to the primary winding by the semiconductor switch circuit. The falling rate dI/dt of the primary current upon interruption thereof by the semiconductor switching circuit is set at a value in a range of 0.2 to 0.4 A/.mu.s. Noise radiation from the ignition coil can be reduced significantly.