Flame sensor and method of using same
First Claim
1. A flame monitor for sensing the presence of flame in a burner, said flame monitor comprising a sensor to sense radiation variation emanating from said flame and to produce a first pulsed signal having a signal to noise ratio, said sensor being operably located adjacent to said flame, an amplifier associated with said sensor to amplify said signal being received from said sensor and to pass said amplified signal to a missing pulses detector and subsequently to a micro-controller, said micro-controller being located remotely from said amplifier and said sensor, said micro-controller being operable to terminate operation of said burner upon receiving a predetermined change in said signal being received from said missing pulses detector, said signal to noise ratio being constant between said sensor and said amplifier, said amplified signal passed to said micro-controller being an analog signal.
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Accused Products
Abstract
A flame sensor for sensing the presence of a flame in a burner. The signal from the sensor is passed to an amplifier located adjacent to the sensor and amplified without having a sensor signal contaminated with common mode radiation. The selectively amplified signal between 15 and 80 Hz is processed by a microcontroller located remotely from the sensor and amplifier which microcontroller may terminate or continue burner operation. The integrity of the connection circuitry between the amplifier and the microcontroller is also monitored and burner shutdown occurs if there is a fault in such circuitry.
22 Citations
13 Claims
- 1. A flame monitor for sensing the presence of flame in a burner, said flame monitor comprising a sensor to sense radiation variation emanating from said flame and to produce a first pulsed signal having a signal to noise ratio, said sensor being operably located adjacent to said flame, an amplifier associated with said sensor to amplify said signal being received from said sensor and to pass said amplified signal to a missing pulses detector and subsequently to a micro-controller, said micro-controller being located remotely from said amplifier and said sensor, said micro-controller being operable to terminate operation of said burner upon receiving a predetermined change in said signal being received from said missing pulses detector, said signal to noise ratio being constant between said sensor and said amplifier, said amplified signal passed to said micro-controller being an analog signal.
- 10. A method for sensing the presence of flame in a burner and for terminating operation of said burner when said flame is not present comprising the steps of sensing the presence of variation in radiation from said flame with a sensor located relatively closely to said flame and sending a pulsed signal having a signal to noise ratio from said sensor to an amplifier when said variation in radiation is sensed, said signal to noise ratio of said pulsed signal being amplified by said amplifier being constant between said sensor and said amplifier, analysing said amplified signal in analog form within a micro-controller located remotely from said amplifier and passing an alarm signal to said micro-controller when said analysed analog signal falls outside a predetermined range.
Specification