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:
Sep. 26, 1978
Filed:
Jan. 24, 1977
Russell Byron Matthews, Goshen, IN (US);
Johnson Controls, Inc., Milwaukee, WI (US);
Abstract
A control circuit for a fuel ignition system of the direct ignition type for providing an interlock on start-up to prevent the energization of a fuel supply valve of the system under certain failure conditions includes an interlock relay which is energized, after a predetermined delay, over normally closed contacts of a flame relay to control a timing network to cause a flame sensing circuit to enable the flame relay to energize the valve during a trial for ignition interval defined by the timing network, the flame sensing circuit maintaining the flame relay, and thus the valve, energized when a flame is provided during the trial for ignition interval, the energization of the valve and the interlock relay being prevented if the normally closed contacts of the flame relay are open on start-up, and the delayed operation of the interlock relay preventing lockout of the system following momentary loss of power.