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. 10, 2006
Filed:
Mar. 07, 2003
John Kociecki, Powell, OH (US);
Yelena N. Kaplan, Columbus, OH (US);
John Kociecki, Powell, OH (US);
Yelena N. Kaplan, Columbus, OH (US);
Ranco Incorporated of Delaware, Wilmington, DE (US);
Abstract
An analog flame sense circuit is provided that utilizes the flame rectification method of sensing flame. The circuit uses an AC voltage source and discrete components to provide the sensing of the flame current. Either a single-pole or a two-pole filter may be used to smooth the generated sense voltage. A DC bias is provided to the filter to ensure a positive voltage. The circuit also includes a high-gain, high-impedance amplifier to translate the high impedance voltage of the sensing portion of the circuit to a relatively low impedance voltage for use by an electronic control circuit. In one embodiment, a high-gain emitter-follower amplifier constructed from two bi-polar junction transistors (BJTs) is used. An integrated Darlington configuration may be used, as well as a single BJT having a high gain, and an integrated operational amplifier.