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. 04, 1977
Filed:
Jan. 12, 1976
Zbynek Antonin Capurka, Glen Ellyn, IL (US);
Ronald William Rumple, Schaumburg, IL (US);
Motorola, Inc., Schaumburg, IL (US);
Abstract
A selective threshold ignition circuit adaptable for use in an electronic ignition system for an engine is disclosed. A magnetic pick-up produces an AC signal about a DC reference level which has a frequency related to the rotational movement produced by the engine. A circuit receives this AC signal and produces a corresponding spark timing signal by comparing the AC signal with a DC threshold level. A selector circuit chooses a first DC threshold level for the comparing circuit which is effectively equal to the DC reference level during the period of engine start up. The selector circuit chooses a second DC threshold level which is different from the DC reference level when the engine is running and before the engine has been started. By providing a threshold level equal to the DC reference level during the engine start up mode of operation, an accurate ignition timing signal is produced during this critical period. By providing a different threshold level during the other modes of engine operation, increased noise immunity is obtained during these other modes of operation which results in lessening the chance of noise transients causing a timing pulse which may result in an unwanted ignition spark.