IR flame amplifier
Patent 4904986 Issued on February 27, 1990. Estimated Expiration Date: 
January 4, 2009. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.
January 4, 2009. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.Patent References 3202976 3299361 3421156 3541549 3742474 3820097 3822408 Flame monitoring apparatus Safety circuit for monitoring a flickering flame Spark ignition gas flow control system InventorAssigneeApplicationNo. 293377 filed on 01/04/1989US Classes:340/578, By radiant energy250/554, Flame light source431/79Photoelectric sensorExaminersPrimary: Swann, III, Glen R.Assistant: Mullen, Thomas J. Jr. Attorney, Agent or FirmInternational ClassesG08B 017/12F23N 005/08 AbstractA flame detector, for use with a photocell which produces a flame signal when the photocell is exposed to a flame, is used for detecting the presence of a flame. An input circuit is coupled to the photocell for receiving and buffering the flame signal. The buffered flame signal is filtered and amplified in a filter. An output circuit further amplifies the filtered flame signal providing an output flame signal. A switch is also used in the flame detector for substantially short circuiting the flame signal to a known value upon receiving a switch-close signal from either a test computer or from a hot refractory detection circuit. A flame-out condition is detected by the hot refractory detection circuit which generates an HRD signal causing the flame signal to be substantially short circuited to a known value thereby eliminating a false flame signal caused by hot refractory shimmering. | |
