Ignition control system for a gas appliance
First Claim
1. An ignition control system for an appliance operating with a source of gas in response to a demand signal, said appliance including a combustion chamber for receiving said gas and containing a flame, comprising, in combination:
- a valve for receiving an interconnect signal and responsively interconnecting said appliance with said source of gas and for receiving a lockout signal for responsively disconnecting said appliance from said source of gas;
an ignition source for receiving a ignition signal and responsively producing a ignite within said combustion chamber to ignite said gas;
a flame sensor for detecting said flame within said combustion chamber, said flame sensor responsively providing a flame signal upon detecting said flame and a blank signal before and after detecting said flame;
a blower for receiving a purge signal and responsively blowing gas out of said combustion chamber;
control means, interconnected to said valve, flame sensor, and blower, for receiving said demand signal and responsively issuing a purge signal to said blower for a first predetermined period and thereafter issuing said interconnect signal to said valve for a second predetermined period after said first predetermined period and for issuing said ignition signal to said spark generator during said second predetermined period, said control means also includinga pulse generator emitting a counting pulse upon said control means receiving a blank signal from said flame sensor after said second predetermined period and a counter for receiving said counting pulse and, after said counter has received a predetermined number of count pulses, issuing a lockout signal to said valve.
2 Assignments
0 Petitions
Accused Products
Abstract
An ignition control system for a direct ignition gas appliance, such as a furnace. A main gas valve, spark generator, flame sensor, and purge blower are all interconnected to a single controller. The controller issues a purge signal to the blower for a first predetermined period. Thereafter, for a second predetermined period, the controller issues an interconnect signal to allow the main gas valve to open and an ignition signal to cause the ignition source to ignite the gas flowing into the appliance from the valve. If the controller thereafter fails to receive a signal from the flame sensor, the attempt at ignition was unsuccessful. After a predetermined number of unsuccessful attempts at ignition, the controller issues a lockout signal to the valve. Moreover, the controller includes redundant circuits for detecting malfunctions within itself and responsively closing the main gas valve.
166 Citations
14 Claims
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1. An ignition control system for an appliance operating with a source of gas in response to a demand signal, said appliance including a combustion chamber for receiving said gas and containing a flame, comprising, in combination:
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a valve for receiving an interconnect signal and responsively interconnecting said appliance with said source of gas and for receiving a lockout signal for responsively disconnecting said appliance from said source of gas; an ignition source for receiving a ignition signal and responsively producing a ignite within said combustion chamber to ignite said gas; a flame sensor for detecting said flame within said combustion chamber, said flame sensor responsively providing a flame signal upon detecting said flame and a blank signal before and after detecting said flame; a blower for receiving a purge signal and responsively blowing gas out of said combustion chamber; control means, interconnected to said valve, flame sensor, and blower, for receiving said demand signal and responsively issuing a purge signal to said blower for a first predetermined period and thereafter issuing said interconnect signal to said valve for a second predetermined period after said first predetermined period and for issuing said ignition signal to said spark generator during said second predetermined period, said control means also including a pulse generator emitting a counting pulse upon said control means receiving a blank signal from said flame sensor after said second predetermined period and a counter for receiving said counting pulse and, after said counter has received a predetermined number of count pulses, issuing a lockout signal to said valve. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14)
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Specification