Ignition and flame detection circuit and fuel gas device

Abstract

The invention provides an ignition and flame detection circuit and a fuel gas device. The circuit comprises an ignition circuit, a control circuit, a flame detection circuit and an amplifying circuit,wherein the ignition circuit comprises a third power supply end, a high-voltage spray point and an air discharge tube, the high-voltage spray point and the air discharge tube are connected to the twoends of the third power supply end and act on a shell, the other end of the air discharge tube is connected with the shell, the control circuit comprises an ignition control end for receiving an ignition signal and a switch circuit for conducting the third power supply end after receiving the ignition signal, the flame detection circuit comprises a first power supply end and a fire detection pinand a third resistor, the fire detection pin and the third resistor are connected to the two ends of the first power supply end, the other end of the third resistor is connected with the shell, the amplifying circuit comprises an operational amplifier, the two input ends of the operational amplifier are connected with the two ends of the third resistor, and the output ends output detection signals. According to the design, the existence and the size of flame can be detected by outputting the detection signals through the output ends of the amplifying circuit, ignition control is realized through the ignition control end, only two chip IO ports are required to realize ignition and detection of the existence and the size of the flame, and the chip resources and the cost are saved.

Description

technical field [0001] The invention relates to the technical field of household appliances, in particular to an ignition and detection circuit and a gas device. Background technique [0002] Gas equipment such as gas water heaters, gas hot air stoves, gas boilers, gas wall-hung boilers, etc., the circuits of these products usually include ignition and detection circuits. The ignition and flame detection circuit needs to be compatible with the dual functions of ignition and flame detection, which is very important for gas equipment. [0003] The principle design of pulse ignition and flame detection is similar. At present, one needle is commonly used for ignition and one needle for flame detection. The ignition needle and fire detection needle respectively control their respective functions. The structure of the double-needle ignition and fire detection burner is relatively complicated; the controller Two output ports are required to control the ignition module and the fire...

AI Technical Summary

Problems solved by technology

[0003] The principle design of pulse ignition and flame detection is similar. At present, one needle is commonly used for ignition and one needle for flame detection. The ignition needle and fire detection needle respectively control their respective functions. The structure of the double-needle ignition and fire detection burner is relatively complicated; the controller Two output ports are required to control the ignition module and the fire detection module separately, and one input port is used to receive the detection signal of the fire detection module, which has certain requirements for the controller chip resources

[0004] And the ignition detection circuit in the prior art often can only detect the presence or absence of the flame, and cannot detect the size of the flame

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