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:
Jan. 17, 1984
Filed:
Aug. 06, 1981
Hitachi, Ltd., Tokyo, JP;
Abstract
The output of a knock sensor for detecting a knock signal of an engine is applied to a bandpass filter for bandpassing only the knock signal. The output of the bandpass filter is applied to an automatic gain control circuit for variably controlling the gain of the knock signal. The output of the automatic gain control circuit is applied to an averaging circuit via a maximum clamp circuit. A comparator supplies an output to an integration circuit of the next stage when the output of the bandpass filter becomes greater than that of the averaging circuit. An ignition control device for controlling the spark timing of an ignition coil energizes the ignition coil by the output from a pick-up coil and that of the integration circuit and delivers a feedback signal to the integration circuit.