Dual-gas source gas control system with anti-gas source misconnection and control circuit thereof

A control circuit, characterized by comprising:

• a power-on circuit, connected in series with an external power supply and an igniter switch to form a loop, comprising a self-locking switch triode connected in series with the external power supply and a self-locking amplifying triode connected to a base electrode of the self-locking switch triode;
• an MCU control circuit, comprising an MCU control chip, wherein the power-on circuit is connected to a power input pin of the MCU control chip, one pin on the MCU control chip is configured to detect whether the power-on circuit is connected, another pinon the MCU control chip is connected to a base electrode of the self-locking amplifying triode in the power-on circuit to be configured to send a driving signal to drive the self-locking amplification triode in the power-on circuit to be turned on when the power-on circuit is detected to be connected, so that the self-locking switch triode and the self-locking amplifying triode are turned on to form self-locking and maintain a power-on state;
• a pulse ignition circuit, comprising an oscillating loop powered by the power-on circuit, wherein the oscillating loop generates an inducted ignition high voltage and discharges to an outside through an external low calorific value gas ignition needle and a high calorific value gas ignition needle connected thereto, and one pin on the MCU control chip sends a control signal to control magnitude of an oscillating voltage of the oscillating loop;
• a gas misconnection flame detection circuit, comprising a comparator powered by the power-on circuit and configured for receiving a flame signal sent from an external flame sensor, wherein a voltage signal generated by the flame sensor is transmitted to one input pin of the comparator, the flame signal is outputted from an output pin of the comparator to a base electrode of a detection amplifying triode connected to the comparator, the flame signal passing through the detection amplifying triode is transmitted onto the MCU control chip through an input pin on the MCU control chip that is connected to the detection amplification triode and that is configured for receiving the flame signal, the flame sensor generates a negative voltage signal to the input pin configured for receiving the flame signal on the comparator when a high calorific value gas is misconnected to a low calorific value gas lighter, the output pin configured for outputting the flame signal on the comparator outputs a high electrical level to the base electrode of the detection amplifying triode, the detection amplifying triode transmits the amplified flame signal to the input pin configured for receiving the flame signal on the MCU control chip, after an output pin on the MCU control chip that is configured for sending a driving signal for driving a gas path to be cut off receives the flame signal indicating misconnection, the output pin sends the driving signal configured for driving the gas path to be cut off to an external corresponding gas path on/off control device, and a cutting off operation of a first solenoid valve in a switch control valve is controlled by the gas path on/off control device.