Fault detection in a flame scanner
Patent 4322723 Issued on March 30, 1982. Estimated Expiration Date: 
September 8, 2000. 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.
September 8, 2000. 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 3476945 3538332 3594746 3846772 Flame monitoring system Passive infrared intruder detection system Patent #: 4242669 InventorAssigneeApplicationNo. 06/185113 filed on 09/08/1980US Classes:340/578, By radiant energy340/507, Fail-safe340/511, Threshold or window (e.g., of analog electrical level)340/600Radiant energyExaminersPrimary: Swann, III, Glen R.Attorney, Agent or FirmInternational ClassF23N 5/08 (20060101)AbstractA flame scanner has a sensing circuit (10) utilizing a photosensitive device (12) for monitoring and a logic circuit (20) which includes a flame detection circuit (22) and a fault detection circuit (24). The photosensitive device produces a current signal (13) indicative of the intensity of the flame. The current signal is fed to a logarithmic amplifier (14) and converted to a voltage signal (15). The voltage signal (15) powers an LED (18) with its output (4) impinging on the photosensitive device (12). The voltage signal (15) is also transmitted to the flame detection circuit and the fault detection circuit for simultaneous and independent processing. The flame detection circuit continuously processes the signal to determine if a stable flame is present, while the fault detection circuit continuously monitors the integrity of the photosensitive device and its associated sensing circuitry. | |
