US3852606A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Flame detection system utilizing a radiation coupling
Assignee: Honeywell Inc
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Filing: 1973-10-12
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Granted: 1974-12-03
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Expires: 1993-10-12
Abstract
Abstract A substantially fail-safe system for detection of flames, particularly flames in a fuel burner. A flame sensing means and amplifier that is responsive to the flicker frequency of a burning flame is coupled by a fail-safe type of circuit to a second safety type of amplifier. The second safety type of amplifier is a cyclic type of amplifier that requires a continuously cycling input signal in order for it to have an output indicating the existence of a flame at the flame sensing means. The fail-safe coupling between the two amplifiers is a radiation emitting device and a radiation responsive device that are electrically isolated, and which are so selected and arranged that the system becomes inoperative upon a number of different types of failures.
Inventors
- 👤 J Kabat
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 04:28
CPC Classifications
F; F23; F23N; F23N5/00; F23N5/02; F23N5/08; F23N5/082; F23N2229/00; F23N2229/08
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
205 words
A fuel burner control system which is adapted to respond to the resistance variations of photocell means exposed to a flame in a fuel burner, including: power supply means having voltage output means; flame flicker amplifier means energized from said voltage output means and having an input adapted to be connected to said photocell means with said amplifier means being capable of amplifying said resistance variations which are representative of the presence of flame; said amplifier means including output circuit means having flicker frequency coupling means and radiation emitting means which emits a flickering radiation when said flame is sensed; voltage divider means including radiation responsive impedance means connected to said voltage output means; said radiation responsive impedance means varying in impedance in response to said radiation of said radiation emitting means; cyclic signal amplifier means having input means connected to saId voltage divider means to respond to variations in current flow in said voltage divider means as said radiation responsive impedance means varying with said flickering radiation from said radiation emitting means; and said cyclic signal amplifier means having output means which is energized only in response to the presence of said flame as represented by said flickering radiation from said radiation emitting means.
Claim 2
Dependent Claim
205 words
A fuel burner control system which is adapted to respond to the resistance variations of photocell means exposed to a flame in a fuel burner, including: power supply means having voltage output means; flame flicker amplifier means energized from said voltage output means and having an input adapted to be connected to said photocell means with said amplifier means being capable of amplifying said resistance variations which are representative of the presence of flame; said amplifier means including output circuit means having flicker frequency coupling means and radiation emitting means which emits a flickering radiation when said flame is sensed; voltage divider means including radiation responsive impedance means connected to said voltage output means; said radiation responsive impedance means varying in impedance in response to said radiation of said radiation emitting means; cyclic signal amplifier means having input means connected to saId voltage divider means to respond to variations in current flow in said voltage divider means as said radiation responsive impedance means varying with said flickering radiation from said radiation emitting means; and said cyclic signal amplifier means having output means which is energized only in response to the presence of said flame as represented by said flickering radiation from said radiation emitting means.
Claim 3
Dependent Claim
28 words
A fuel burner control system as described in claim 1 wherein said flame flicker amplifier means is responsive to an infrared flame flicker frequency created by said flame.
Claim 4
Dependent Claim
19 words
A fuel burner control system as described in claim 1 wherein said flicker frequency coupling means is a capacitor.
Claim 5
Dependent Claim
31 words
A fuel burner control system as described in claim 3 wherein said radiation emitting means is light emitting semiconductor means and said radiation responsive impedance means is light responsive semiconductor means.
Claim 6
Dependent Claim
60 words
A fuel burner control system as described in claim 1 wherein said voltage divider means including said radiation responsive impedance means is so selected and arranged that said cyclic signal amplifier input means can receive a varying current flow within an operating range of said cyclic signal amplifier means only when said voltage divider means has a predetermined voltage range.
Claim 7
Dependent Claim
19 words
A fuel burner control system as described in claim 5 wherein said flicker frequency coupling means is a capacitor.
Claim 8
Dependent Claim
31 words
A fuel burner control system is described in claim 6 wherein said radiation emitting means is light emitting semiconductor means and said radiation responsive impedance means is light responsive semiconductor means.
Claim 9
Dependent Claim
30 words
A fuel burner control system as described in claim 7 wherein said voltage divider means includes a Zener diode and said light emitting semiconductor means is a light emitting diode.
Claim 10
Dependent Claim
53 words
A fuel burner control system as descirbed in claim 8 wherein said light responsive semiconductor means is connected to cyclically shunt current in said voltage divider means past the input circuit means of said cyclic signal amplifier means in response to said flickering radiation from the light emitting diode when flame is sensed.
Claim 11
Dependent Claim
28 words
A fuel burner control system as described in claim 9 wherein said flame flicker amplifier means is responsive to an infrared flame flicker frequency created by said flame.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-12-02 | 1978-06-03 | 1978-12-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-12-02 | 1982-06-03 | 1982-12-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-12-02 | 1986-06-03 | 1986-12-03 | $7700.00 | Window Closed / Lapsed |