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. 22, 1985
Filed:
Sep. 21, 1983
Hitachi, Ltd., Tokyo, JP;
Abstract
A flame-rod type flame detecting apparatus for detecting flames produced intermittently in a pulse-like combustion process is disclosed. An oscillation circuit generates an A.C. flame detecting voltage to be applied across the flame to be detected. The A.C. voltage modulated by the flame provides a signal representative of the presence of flame. The frequency of the A.C. voltage is selected higher than the commercial line frequency and higher than a maximum frequency of the pulse-like intermittent combustion and selected such that the positive half-waves of the applied A.C. voltage are superposed on the flames produced intermittently, and more preferably at least one positive half-wave is superposed on each of the flames.