A method of determining presence of a flame in a furnace of a heating, ventilation, and air conditioning (HVAC) system. The method comprises determining, using a controller, whether a processor signal (G) is active, responsive to a determination that the processor signal (G) is active, determining, using the controller prior to assertion of a flame-test input control signal, an output state of a first comparator, responsive to a determination that the output state of the first comparator is high, determining, using the controller prior to assertion of the flame-test input control signal, an output state of a second comparator, and responsive to a determination that the output state of the second comparator is low, transmitting, using the controller, a notification that a flame is present.

A barbecue arrangement comprising a barbecue body having a cooking volume, one or more burners positioned to provide heat to the cooking volume; a gas source adapted to supply a gas to the one or more burners, and one or more control means to control the flow of gas from the gas source to the one or more burners producing a flame when the gas is ignited; a flame detection assembly, the flame detection assembly adapted to sense the flame from the one or more burners and a control means adapted to shut off the gas flow to the one or more burners if the flame is not detected within a pre-determined period of time.

A digital gas cooking appliance is disclosed. The digital gas cooking appliance has the ability of self-initiating an automatic calibration process to determine an optimum valve position to be used for an electromechanical valve when igniting a gas cooking element by performing a plurality of ignition sequences for the gas cooking element at a plurality of respective valve positions of the electromechanical valve. During each of the plurality of ignition sequences, a respective ignition duration between a start of the respective ignition sequence when an igniter is active and the electromechanical valve is open, and a flame is detected by a flame detector, may be determined.

Various embodiments include a combustion apparatus comprising: a facility for open- and/or closed-loop control of the apparatus; a combustion chamber; an actuator adjusting an air supply; and a combustion sensor in a region of a flame of the chamber. The controller stores a list of support points. A first air supply value is assigned to each support point. A drift test value and an index for ascertainment of a test result are assigned to each support point. The controller: generates a specified air supply; selects a support point as a function of the air supply; and decides on a test result using the index for the support point. To ascertain a test result: receives a signal from the combustion sensor; determines a new test result; ascertains a changed drift test value for the selected support point; and stores the changed drift test value as the drift test value.

Flame monitoring device (23) for a gas burner appliance (10), the gas burner appliance (10) being configured to burn a combustible gas, the combustion of the combustible gas resulting into a flame (12), comprising a flame supervision device (24) providing as measurement signal an electrical voltage signal depending on the presence of the flame (12), and an electronic circuit (25) converting the electrical voltage signal provided by the flame supervision device (24) into an electrical current signal.

A gas burner system has a gas burner with a conduit through which an air-gas mixture is conducted; a variable-speed forced-air device that forces air through the conduit; a control valve that controls a supply of gas for mixture with the air to thereby form the air-gas mixture; and an electrode configured to ignite the air-gas mixture so as to produce a flame. The electrode is further configured to measure a flame ionization current associated with the flame. A controller is configured to actively control the variable-speed forced-air device based on the flame ionization current measured by the electrode so as to automatically avoid a flame harmonic mode of the gas burner. Corresponding methods are provided.

A gas burner system and corresponding methods include a gas burner through which an air-gas mixture is conducted; a variable-speed forced-air device that forces air through the gas burner; a control valve that controls a supply of gas for mixture with the air to thereby form the air-gas mixture; an electrode configured to ignite the air-gas mixture and produce a flame, wherein the electrode is further configured to measure an actual flame strength of the flame; a controller; and an input device for inputting a calibration command to the controller. Upon receipt of the calibration command, the controller is configured to automatically calibrate and save the target flame strength set point and thereafter automatically regulate a speed of the variable-speed forced-air device to cause the actual flame strength to achieve the target flame strength set point.

Systems and methods for detecting the presence of a burner flame using flame rectification are shown and described. A conductive flame sensor is positioned to conduct electricity to a burner flame when the burner is lit. The flame provides a conductive path to the burner conductive body and when operatively connected to an alternating current source, half-wave rectifies the current flowing to the sensor. A flame sensing circuit provides an output signal that is conditioned for use as an input to a flame indicator and/or a controller that is configured to shut off gas flow to the burner when no flame is present after an attempt at igniting the burner.

In some examples, a method for operating a gas burner appliance includes determining, on basis of a nominal burner-load and on basis of a mixing ratio of gas and air of a gas/air mixture or a λ-value of the gas/air mixture, a nominal air mass flow in order to provide the nominal burner-load. The method further comprises determining the ambient air pressure and the ambient air temperature of the ambient air, determining, on basis of the ambient air pressure and on basis of the ambient air temperature, the atmospheric density of the ambient air, determining on basis of the nominal air mass flow, on basis of the determined atmospheric density of the ambient air, and on basis of a system resistance of the gas burner appliance, the fan speed of the fan in order to provide the nominal burner-load.

A flame sensor for a furnace of a heating, ventilation, and air conditioning (HVAC) system includes a sensor body and an electrically conductive member of the sensor body. The electrically conductive member is configured to be disposed within a flame region of a burner of the furnace and configured to receive electrical current from a controller of the furnace. The flame sensor also includes an anti-oxidation coating disposed on an outer surface of the electrically conductive member and configured to transmit the electrical current from the electrically conductive member. The anti-oxidation coating is configured to contact a flame produced by the burner and expose the electrical current to the flame.