| abstract |
The invention discloses a gas circuit and a gas device for detecting an air-fuel ratio. The gas circuit comprises: a charging and discharging module, a first end of the charging and discharging module is connected to a power supply module, and a second end of the charging and discharging module passes through a flame grounding; the sampling module includes a sampling capacitor and a first bidirectional trigger module connected in parallel with each other, one end of the sampling module is connected to the second end of the charging and discharging module through the protection resistor, and the other end of the sampling module is grounded; The air-fuel ratio detection module is provided with an input end and a signal output end, the input end is connected with the second end of the charging and discharging module, and the signal output end is connected with the signal receiving port of the control chip; the control chip is used for The duration of the first electrical signal is detected. In this way, when the ratio of oxygen to fuel gas is appropriate, the combustion is just sufficient, and at this time, the signal receiving port detects the low level for the longest duration. Therefore, it can be used to adjust the air-fuel ratio. |