US3822981A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Flame monitoring system
Assignee: Kidde Inc
•
Filing: 1972-06-23
•
Granted: 1974-07-09
•
Expires: 1992-06-23
Abstract
Abstract Disclosed is a burner control system in which fuel flow is maintained by an operator in response to a flame signal produced by a capacitor charged by flame rectified current. System operation is initiated by precharging the capacitor from an auxiliary direct current source while preventing the operator from supplying fuel. Subsequently, the operator is activated simultaneously with disconnection of the auxiliary direct current source from the capacitor.
Inventors
- 👤 L Bridge
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 19:58
CPC Classifications
F; F23; F23N; F23N5/00; F23N5/02; F23N5/12
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
199 words
Circuit apparatus for controlling a fuel burner and comprising a source of alternating current voltage; a flame sensing electrode for disposition adjacent a fuel burner in the region occupied by flame emanating therefrom; direct current sensing means coupled to said flame sensing electrode and adapted to provide a flame signal in response to current rectified by flame in said region; fuel control circuit means for controlling the flow of fuel to said fuel burner; said fuel control circuit means being coupled to said direct current sensing means and adapted to provide fuel flow to said burner in response to said flame signal; direct current source means for supplying direct current to said direct current sensing means; and operator means operative in one state to simultaneously establish flow of direct current from said direct current source to said direct current sensing means and prevent said fuel control circuit means from providing fuel flow to said burner, and operative in a second state to simultaneously prevent flow of direct current from said direct current source to said direct current sensing means and allow said fuel control circuit means to provide fuel flow to said burner in response to said flame signal.
Claim 2
Dependent Claim
199 words
Circuit apparatus for controlling a fuel burner and comprising a source of alternating current voltage; a flame sensing electrode for disposition adjacent a fuel burner in the region occupied by flame emanating therefrom; direct current sensing means coupled to said flame sensing electrode and adapted to provide a flame signal in response to current rectified by flame in said region; fuel control circuit means for controlling the flow of fuel to said fuel burner; said fuel control circuit means being coupled to said direct current sensing means and adapted to provide fuel flow to said burner in response to said flame signal; direct current source means for supplying direct current to said direct current sensing means; and operator means operative in one state to simultaneously establish flow of direct current from said direct current source to said direct current sensing means and prevent said fuel control circuit means from providing fuel flow to said burner, and operative in a second state to simultaneously prevent flow of direct current from said direct current source to said direct current sensing means and allow said fuel control circuit means to provide fuel flow to said burner in response to said flame signal.
Claim 3
Dependent Claim
44 words
Circuit apparatus according to claim 1 wherein said direct current sensing means comprises electrical energy storage means for storing energy present in said current rectified by flame, and said flame signal is provided by a given stored energy level in said energy storage means.
Claim 4
Dependent Claim
35 words
Circuit apparatus according to claim 2 wherein said energy storage means comprises a capacitor that is charged by said current rectified by flame and by said direct current supplied by said direct current source means.
Claim 5
Dependent Claim
48 words
Circuit apparatus according to claim 2 wherein said operator means comprises switch means operative in said one state to connect said direct current energy source to said energy storage means, and operative in said second state to disconnect said direct current energy source from said energy storage means.
Claim 6
Dependent Claim
22 words
Circuit apparatus according to claim 2 wherein said direct current source comprises rectifier means connected to said source of alternating current voltage.
Claim 7
Dependent Claim
25 words
Circuit apparatus according to claim 2 wherein said fuel control circuit means comprises an electrically controlled actuator for a valve supplying fuel to said burner.
Claim 8
Dependent Claim
64 words
Circuit apparatus according to claim 6 wherein said operator means comprises switch means operative in said one state to simultaneously connect said direct current energy source to said energy storage means and to prevent energization of said valve actuator, and in said second state to simultaneously disconnect said direct current energy source from said energy storage means and allow energization of said valve actuator.
Claim 9
Dependent Claim
66 words
Circuit apparatus according to claim 7 wherein said switch means comprises double-throw switch means that in one position connects said energy storage means to said direct current energy source and disconnects said valve actuator from any source of energization, and in a second position disconnects said energy storage means from said direct current energy source and connects said valve actuator to said fuel control circuit means.
Claim 10
Dependent Claim
31 words
Circuit apparatus according to claim 8 wherein said valve actuator comprises an operating solenoid and an SCR that provides energizing current to said operating solenoid in response to said flame signal.
Claim 11
Dependent Claim
153 words
A burner safety timer control circuit adapted to be connected to a source of alternating current voltage and to rectification flame sensor means of a fuel burner, including: capacitive means and rectification means connected to said alternating current voltage source upon energization of said burner control circuit to supply an initial charge to said capacitive means; current drain means connected to said capacitive means to slowly drain said capacitive means of said initial charge; solid-state current control means having an input connected to said capacitive means and output means adapted to be connected to operate said fuel burner when said capacitive means charge is maintained; and connection means adapted to connect said rectification flame sensor means to said capacitive means to supply a charge to said capacitive means when said fuel burner has a proper flame to maintain said charge and keep said solid-state current control means output means operating said fuel burner.
Claim 12
Dependent Claim
153 words
A burner safety timer control circuit adapted to be connected to a source of alternating current voltage and to rectification flame sensor means of a fuel burner, including: capacitive means and rectification means connected to said alternating current voltage source upon energization of said burner control circuit to supply an initial charge to said capacitive means; current drain means connected to said capacitive means to slowly drain said capacitive means of said initial charge; solid-state current control means having an input connected to said capacitive means and output means adapted to be connected to operate said fuel burner when said capacitive means charge is maintained; and connection means adapted to connect said rectification flame sensor means to said capacitive means to supply a charge to said capacitive means when said fuel burner has a proper flame to maintain said charge and keep said solid-state current control means output means operating said fuel burner.
Claim 13
Dependent Claim
23 words
A circuit according to claim 10 including isolation means for isolating said capacitive means from the supply of charge from said rectification means.
Claim 14
Dependent Claim
24 words
A circuit according to claim 11 including delay means for operating said isolation means a given period after energization of said burner control circuit.
Claim 15
Dependent Claim
14 words
A circuit according to claim 12 wherein said isolation means comprises a relay means.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-07-08 | 1978-01-07 | 1978-07-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-07-08 | 1982-01-07 | 1982-07-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-07-08 | 1986-01-07 | 1986-07-09 | $7700.00 | Window Closed / Lapsed |