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:
Dec. 16, 1980
Filed:
Sep. 07, 1978
Applicant:
Inventors:
Toshio Tanaka, Toride, JP;
Sumio Nakagawa, Tokyo, JP;
Assignee:
Hitachi, Ltd., , JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
F23N / ; F23Q / ; F23Q / ; F23N / ;
U.S. Cl.
CPC ...
431 24 ; 431 15 ; 431 26 ; 431 73 ;
Abstract
A check circuit for checking operation of timers of a digital type combustion process control apparatus comprises flip-flops each having a preset terminal. The preset state of the flip-flops is inverted by an operation starting signal. The inversion is detected by a detector circuit the output signal of which is utilized for driving the control circuits for a combustion apparatus. The detector circuit is composed of a flip-flop circuit having input terminals applied with the operation initiating signal and the inverted output signal from the timer circuit.