Toxic gas detector control circuit capable of resisting electromagnetic interference

Abstract

The invention provides a toxic gas detector control circuit capable of resisting electromagnetic interference, which comprises a power supply voltage regulation circuit, a temperature signal acquisition circuit, a sensor voltage regulation circuit, a sensor acquisition control circuit and a gas detector main control circuit which are in power supply connection, the gas detector main control circuit is in control connection with the 485 communication circuit, the acousto-optic prompt circuit, the LED state display circuit and the digital display screen, the gas detector main control circuit is in communication connection with the sensor acquisition control circuit, and the sensor acquisition control circuit is in control connection with the gas signal acquisition circuit and the temperature signal acquisition circuit. A TVS (Transient Voltage Suppressor) tube, a common mode inductor and a diode are arranged in the power supply voltage adjusting circuit; and a TVS tube and a diode are also arranged in the gas detector main control circuit. The poisonous gas detector has the beneficial effects that the anti-electromagnetic interference capability, the reliability and the stability of the poisonous gas detector when the poisonous gas detector is independently used are greatly improved.

Description

Technical Field

[0001] The present invention relates to the technical field of gas detection, and in particular to a toxic gas detector control circuit capable of resisting electromagnetic interference. Background Art

[0002] A gas detector is an instrument that measures gas concentrations. Suitable for hazardous locations where flammable or toxic gases are present, it provides long-term, continuous monitoring of the air's concentration of the target gas within its lower explosive limit. It is widely used in various industries, including gas, petrochemicals, metallurgy, steel, coking, and power generation, where flammable or toxic gases are present, and is a crucial instrument for ensuring property and personal safety. Gas detectors utilize catalytic combustion and electrochemical gas sensors as detection elements, requiring high sensitivity and fast response times. They typically feature a die-cast aluminum housing and meet certain explosion-proof rating requirements. Gas detectors are categorized as either flammable or toxic, depending on the type of gas being detected. Toxic gas detectors typically detect toxic gases such as carbon monoxide, hydrogen sulfide, ammonia, and sulfur dioxide. Currently, the industry is experiencing rapid development, with a move towards wireless functionality and miniaturization. Improved communication capabilities facilitate the integration of detectors into various devices and machines without compromising their ability to detect toxic or flammable gases at a safe distance.

[0003] In existing technology, toxic gas detectors typically form a combustible gas detection and alarm system with an alarm controller and linkage devices (such as fans and solenoid valves). Toxic gas detectors are typically powered by direct current (DC), while alarm controllers are powered by alternating current (AC). The toxic gas detectors' power comes from power conversion within the alarm controller. According to standards, alarm controllers undergo multiple electromagnetic compatibility (EMC) tests during inspection and certification, or during type evaluation, and these tests must be performed alongside corresponding detector models.

[0004] According to the standard requirements, during the inspection and certification or type evaluation process of the inspection institute, toxic gas detectors are required to reduce a variety of electromagnetic compatibility-related items because they are DC-powered devices. This leads to the DC-powered toxic gas detectors having weakened anti-interference protection capabilities in terms of design requirements. When they are disconnected from the alarm controller and used alone, they cannot guarantee high anti-electromagnetic interference capabilities. When they are subject to electromagnetic interference, the concentration value displayed by the toxic gas detector may experience irregular jumps and false alarms, and may even cause shutdowns and freezes, resulting in a poor user experience. Summary of the Invention

[0005] In order to solve the problems in the prior art, the present invention provides a toxic gas detector control circuit that is resistant to electromagnetic interference. The toxic gas detector control circuit that is resistant to electromagnetic interference is provided with a power supply voltage adjustment circuit, a sensor voltage adjustment circuit, a gas detector main control circuit, a sensor acquisition control circuit, a gas signal acquisition circuit, a temperature signal acquisition circuit, a 485 communication circuit, an audio-visual prompt circuit, an LED status display circuit and a digital display screen that cooperate with each other. The power supply voltage adjustment circuit is provided with a TVS tube, a common-mode inductor and a diode. The 485 communication circuit is also provided with a common-mode inductor and multiple TVS tubes. The gas detector main control circuit is also provided with a TVS tube and a diode. The TVS tube, common-mode inductor and diode can enhance the anti-electromagnetic interference capability of the gas detector main control circuit, the 485 communication circuit and the power supply voltage adjustment circuit. That is, through multiple electronic circuit protection measures, the anti-electromagnetic interference capability, reliability and stability of the toxic gas detector when used alone are greatly improved, thereby solving the problem in the prior art that the toxic gas detector has poor anti-electromagnetic interference capability and is prone to malfunction when used alone.

[0006] The present invention provides a toxic gas detector control circuit capable of resisting electromagnetic interference, comprising a power supply voltage adjustment circuit, a sensor voltage adjustment circuit, a gas detector main control circuit, a sensor acquisition control circuit, a gas signal acquisition circuit, a temperature signal acquisition circuit, a 485 communication circuit, an audio-visual prompt circuit, an LED status display circuit, and a digital display screen. The input end of the power supply voltage adjustment circuit is connected to a 24V DC power supply, the output end of the power supply voltage adjustment circuit is connected to the temperature signal acquisition circuit, the gas signal acquisition circuit, the sensor voltage adjustment circuit, the sensor acquisition control circuit, and the gas detector main control circuit for power supply, the output end of the sensor voltage adjustment circuit is connected to the gas signal acquisition circuit for power supply, the output end of the gas detector main control circuit is connected to the input end of the 485 communication circuit, the input end of the audio-visual prompt circuit, the input end of the LED status display circuit, and the input end of the digital display screen. The gas detector main control circuit is also communicatively connected to the sensor acquisition control circuit, and the sensor acquisition control circuit is connected to the gas signal acquisition circuit. The collecting circuit and the temperature signal acquisition circuit are controlled and connected. The gas detector main control circuit is provided with a current loop module and a relay module. The gas signal acquisition circuit is provided with a toxic gas acquisition sensor. The gas signal acquisition circuit can collect the concentrations of carbon monoxide, hydrogen sulfide, ammonia and sulfur dioxide gases. The power supply voltage adjustment circuit is provided with a TVS tube, a common-mode inductor and a diode. The 485 communication circuit is also provided with a common-mode inductor and multiple TVS tubes. The gas detector main control circuit is also provided with a TVS tube and a diode. The TVS tube, common-mode inductor and diode can improve the anti-electromagnetic interference capability of the gas detector main control circuit, the 485 communication circuit and the power supply voltage adjustment circuit.

[0007] The present invention is further improved. The gas detector main control circuit is provided with a detector main control chip U5, a crystal oscillator X1, a magnetic bead B1, a magnetic bead B2, a capacitor C14, a capacitor C16 and a capacitor C18. The detector main control chip U5 is provided with 48 pins. The 1st pin of the detector main control chip U5 is connected to the output end of the power supply voltage adjustment circuit, the 31st, 29th and 30th pins of the detector main control chip U5 are connected to the input end of the 485 communication circuit, the 11th and 46th pins of the detector main control chip U5 are connected to the input end of the sound and light prompt circuit, and the 16th, 15th, 14th and 28th pins of the detector main control chip U5 are connected to the input end of the LED status display circuit. Pins 20, 19, and 18 of the detector main control chip U5 are connected to the input end of the digital display screen, pins 5 and 6 of the detector main control chip U5 are connected to the sensor acquisition control circuit, pin 5 of the detector main control chip U5 is connected to one end of the magnetic bead B1, pin 6 of the detector main control chip U5 is connected to one end of the magnetic bead B2 and one end of the capacitor C18, the other end of the magnetic bead B1 is connected to one end of the capacitor C14 and one end of the crystal oscillator X1, the other end of the magnetic bead B2 is connected to one end of the capacitor C16 and the other end of the crystal oscillator X1, the other end of the capacitor C14, the other end of the capacitor C16, and the other end of the capacitor C18 are grounded.

[0008] The present invention is further improved. The main control circuit of the gas detector is further provided with a current loop chip U11, a transistor Q1, a field effect transistor Q2, a capacitor C19, a resistor R17, a diode D12, a TVS tube D11, a relay K1 and a transistor Q3. The current loop chip U11 is provided with 10 pins. The 4th pin of the current loop chip U11 is connected to the 4th pin of the detector main control chip U5. The 6th pin of the current loop chip U11 can receive an external AD digital signal. The 2nd pin of the current loop chip U11 is connected to the emitter of the transistor. The 3rd pin of the current loop chip U11 is connected to the collector of the transistor and the gate of the field effect transistor Q2. The base of the transistor is connected to the field effect transistor Q2. The source of the field effect tube Q2 is connected to the source, the drain of the field effect tube Q2 is connected to one end of the capacitor C19 and one end of the resistor R17, the other end of the resistor R17 is connected to the positive electrode of the diode D12, the cathode of the diode D12 is connected to one end of the TVS tube D11, the cathode of the diode D12 can output a current signal, the other end of the TVS tube D11 and the other end of the capacitor C19 are grounded; the relay K1 is provided with 5 pins, the second pin of the relay K1 is connected to the collector of the transistor Q3, the base of the transistor Q3 is connected to the third pin of the detector main control chip U5, the emitter of the transistor Q3 is grounded, and the 3rd, 4th and 5th pins of the relay K1 can be connected to other external electronic devices.

[0009] The present invention is further improved. The power supply voltage adjustment circuit is provided with a voltage stabilizing chip U1, a voltage stabilizing chip U2, a voltage stabilizing chip U3, a fuse resistor F1, a diode D10, a TVS tube D1, a common-mode inductor L1, a capacitor C4, an inductor L2, a capacitor C7, a capacitor C8 and a capacitor C9. The voltage stabilizing chip U1 is provided with 6 pins, the voltage stabilizing chip U2 is provided with 3 pins, and the voltage stabilizing chip U3 is provided with 5 pins. The 4th pin of the voltage stabilizing chip U1 is connected to the output end of the common-mode inductor L1, one end of the capacitor C4, and one end of the capacitor C7. The input end of the common-mode inductor L1 is connected to one end of the TVS tube D1 and one end of the fuse resistor F1. The other end of the fuse resistor F1 is connected to the cathode of the diode D10. The anode of the diode D10 is connected to a 24V DC power supply, the 6th pin of the voltage stabilizing chip U1 is connected to one end of the inductor L2, the other end of the inductor L2 is connected to one end of the capacitor C8, one end of the capacitor C9, the 3rd pin of the voltage stabilizing chip U2, and the 1st pin of the voltage stabilizing chip U3, the 2nd pin of the voltage stabilizing chip U2 is connected to the 1st pin of the detector main control chip U5 for power supply, the 5th pin of the voltage stabilizing chip U3 is connected to the sensor voltage adjustment circuit, the sensor acquisition control circuit, the temperature signal acquisition circuit, and the gas signal acquisition circuit for power supply, the other end of the TVS tube D1, the other end of the capacitor C7, the other end of the capacitor C8, and the other end of the capacitor C9 are grounded; a voltage stabilizing chip U4 is provided in the sensor voltage adjustment circuit, and the voltage stabilizing chip U4 is provided with 5 pins, the 3rd and 5th pins of the voltage stabilizing chip U4 are connected to the 5th pin of the voltage stabilizing chip U3, and the 4th pin of the voltage stabilizing chip U4 is connected to the gas signal acquisition circuit for power supply.

[0010] The present invention is further improved. A sensor acquisition control chip U13 is provided in the sensor acquisition control circuit. The sensor acquisition control chip U13 is provided with 20 pins. The second pin of the sensor acquisition control chip U13 is connected to the fifth pin of the voltage stabilizing chip U3. The first and 20 pins of the sensor acquisition control chip U13 are respectively connected to the sixth and fifth pins of the detector main control chip U5. The sixth pin of the sensor acquisition control chip U13 is controlled and connected to the gas signal acquisition circuit. The fifth pin of the sensor acquisition control chip U13 is controlled and connected to the temperature signal acquisition circuit.

[0011] The present invention is further improved. The gas signal acquisition circuit is provided with an operational amplifier U14A, a resistor R12, a resistor R13, a resistor R14, an inductor L3 and a capacitor C17. The non-inverting input terminal of the operational amplifier U14A is connected to one end of the resistor R14, and the other end of the resistor R14 is connected to the 4th pin of the voltage regulator chip U4. The inverting input terminal of the operational amplifier U14A is connected to one end of the resistor R13, and the other end of the resistor R13 is connected to one end of the inductor L3. The other end of the inductor L3 is connected to a toxic gas acquisition sensor. The output terminal of the operational amplifier U14A is connected to one end of the resistor R12, and the other end of the resistor R12 is connected to the 6th pin of the sensor acquisition control chip U13.

[0012] The present invention is further improved. A temperature signal acquisition chip U15 and a capacitor C12 are provided in the temperature signal acquisition circuit. The temperature signal acquisition chip U15 is provided with three pins. The first pin of the temperature signal acquisition chip U15 is connected to the fifth pin of the voltage stabilizing chip U3 and one end of the capacitor C12. The second pin of the temperature signal acquisition chip U15 is connected to the fifth pin of the sensor acquisition control chip U13. The third pin of the temperature signal acquisition chip U15 and the other end of the capacitor C12 are grounded.

[0013] The present invention is further improved. The 485 communication circuit is provided with a 485 communication chip U6, a common-mode inductor L6, a TVS tube D7 and a TVS tube D9, wherein the 485 communication chip U6 is provided with 8 pins, the 1st, 3rd and 4th pins of the 485 communication chip U6 are respectively connected to the 31st, 29th and 30th pins of the detector main control chip U5, the 8th pin of the 485 communication chip U6 is connected to the 2nd pin of the voltage stabilizing chip U2, the 6th and 7th pins of the 485 communication chip U6 are connected to one end of the common-mode inductor L6, the other end of the common-mode inductor L6 can be connected to an external 485 communication device, the other end of the common-mode inductor L6 is also connected to the negative pole of the TVS tube D7 and the negative pole of the TVS tube D9, and the positive pole of the TVS tube D7 and the positive pole of the TVS tube D9 are grounded.

[0014] The present invention is further improved. The sound and light prompt circuit is provided with a transistor Q4, a speaker prompt interface J6, a transistor Q5 and a light prompt interface J7, wherein the base of the transistor Q4 is connected to the 11th pin of the detector main control chip U5, the collector of the transistor Q4 is connected to the input end of the speaker prompt interface J6, the output end of the speaker prompt interface J6 can be connected to an external speaker, the emitter of the transistor Q4 is grounded, the base of the transistor Q5 is connected to the 46th pin of the detector main control chip U5, the collector of the transistor Q5 is connected to the input end of the light prompt interface J7, the output end of the light prompt interface J7 can be connected to an external light-emitting LED lamp, and the emitter of the transistor Q5 is grounded. ; The LED status display circuit is provided with a light-emitting diode D1, a light-emitting diode D2, a light-emitting diode D3 and a light-emitting diode D4, wherein the positive pole of the light-emitting diode D1, the positive pole of the light-emitting diode D2, the positive pole of the light-emitting diode D3 and the positive pole of the light-emitting diode D4 are connected to the 2nd pin of the voltage regulator chip U2, the cathode of the light-emitting diode D1 is connected to the 16th pin of the detector main control chip U5, the cathode of the light-emitting diode D2 is connected to the 15th pin of the detector main control chip U5, the cathode of the light-emitting diode D3 is connected to the 14th pin of the detector main control chip U5, and the cathode of the light-emitting diode D4 is connected to the 28th pin of the detector main control chip U5.

[0015] The present invention is further improved. The model of the detector main control chip U5 is STM32F103C8T6, the model of the current loop chip U11 is XTR111, the model of the voltage regulator chip U1 is LM2842, the model of the voltage regulator chip U2 is AMS1117-3V3, the model of the voltage regulator chip U3 is TPS76333DBV, the model of the voltage regulator chip U4 is TLV376IDBVR, the model of the sensor acquisition control chip U13 is STM32C011F4U6TR, the model of the temperature signal acquisition chip U15 is TMP235A2DBZR, and the model of the 485 communication chip U6 is SN65HVD72.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows: providing a toxic gas detector control circuit capable of resisting electromagnetic interference, by arranging a power supply voltage adjustment circuit, a sensor voltage adjustment circuit, a gas detector main control circuit, a sensor acquisition control circuit, a gas signal acquisition circuit, a temperature signal acquisition circuit, a 485 communication circuit, an audio-visual prompt circuit, an LED status display circuit and a digital display screen that cooperate with each other in the toxic gas detector control circuit capable of resisting electromagnetic interference, a TVS tube, a common-mode inductor and a diode are arranged in the power supply voltage adjustment circuit, a common-mode inductor and multiple TVS tubes are also arranged in the 485 communication circuit, and a TVS tube and a diode are also arranged in the gas detector main control circuit. Diodes, TVS tubes, common-mode inductors, and diodes can improve the anti-electromagnetic interference capability of the gas detector's main control circuit, 485 communication circuit, and power supply voltage adjustment circuit. That is, through multiple electronic circuit protection measures, the anti-electromagnetic interference capability of the toxic gas detector when used alone is greatly improved, and the reliability and stability of the toxic gas detector are improved. When the toxic gas detector is used alone without power supply from the alarm controller or external power supply, it can accurately detect the concentration of combustible gas in real time, and can adapt to various complex interference environments, thereby improving the user experience and solving the problem of poor anti-electromagnetic interference capability and prone to failure of toxic gas detectors in the existing technology when used alone. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the present invention or the solutions in the prior art, a brief introduction is given below to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0018] Figure 1 This is a principle block diagram of a control circuit for a toxic gas detector capable of resisting electromagnetic interference according to the present invention;

[0019] Figure 2 A circuit diagram of a main control circuit of a gas detector of the present invention;

[0020] Figure 3 A circuit diagram of a main control circuit of a gas detector of the present invention;

[0021] Figure 4 A circuit diagram of a main control circuit of a gas detector of the present invention;

[0022] Figure 5 A circuit diagram of a main control circuit of a gas detector of the present invention;

[0023] Figure 6 is a circuit diagram of a power supply voltage regulating circuit of the present invention;

[0024] Figure 7 is a circuit diagram of a power supply voltage regulating circuit of the present invention;

[0025] Figure 8 A circuit diagram of a sensor acquisition control circuit of the present invention;

[0026] Figure 9 A circuit diagram of a gas signal acquisition circuit according to the present invention;

[0027] Figure 10 A circuit diagram of a temperature signal acquisition circuit according to the present invention;

[0028] Figure 11 A circuit diagram of the 485 communication circuit of the present invention;

[0029] Figure 12 It is a circuit diagram of the sound and light prompt circuit of the present invention. DETAILED DESCRIPTION

[0030] Unless otherwise defined, all technical and scientific terms used herein have the same meanings as commonly understood by those skilled in the art to which the present invention belongs. The terms used in the specification of the application are for the purpose of describing specific embodiments only and are not intended to limit the present invention. The terms "including" and "having" and any variations thereof in the specification and claims of the present invention and the accompanying drawings are intended to cover non-exclusive inclusions. The terms "first" and "second" in the specification and claims of the present invention or the accompanying drawings are used to distinguish different objects, not to describe a specific order.

[0031] References herein to "embodiments" mean that a particular feature, structure, or characteristic described in connection with the embodiments may be included in at least one embodiment of the present invention. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute a separate or alternative embodiment that is mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0032] In order to enable those skilled in the art to better understand the solutions of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings.

[0033] like Figures 1-12As shown, the present invention provides a toxic gas detector control circuit that is resistant to electromagnetic interference, including a power supply voltage adjustment circuit, a sensor voltage adjustment circuit, a gas detector main control circuit, a sensor acquisition control circuit, a gas signal acquisition circuit, a temperature signal acquisition circuit, a 485 communication circuit, an audio and light prompt circuit, an LED status display circuit and a digital display screen. The input end of the power supply voltage adjustment circuit is connected to a 24V A DC power supply, the output end of the power supply voltage adjustment circuit is connected to the temperature signal acquisition circuit, the gas signal acquisition circuit, the sensor voltage adjustment circuit, the sensor acquisition control circuit, and the gas detector main control circuit. The output end of the sensor voltage adjustment circuit is connected to the gas signal acquisition circuit. The output end of the gas detector main control circuit is controlled and connected to the input end of the 485 communication circuit, the input end of the sound and light prompt circuit, the input end of the LED status display circuit, and the input end of the digital display screen. The gas detector main control circuit is also communicatively connected to the sensor acquisition control circuit. The sensor acquisition control circuit is controlled and connected to the gas signal acquisition circuit and the temperature signal acquisition circuit. A current loop module and a relay module are provided in the gas detector main control circuit. A toxic gas acquisition sensor is provided in the gas signal acquisition circuit. The gas signal acquisition circuit can collect the concentrations of carbon monoxide, hydrogen sulfide, ammonia and sulfur dioxide gases. In this embodiment, a TVS tube, a common-mode inductor and a diode are provided in the power supply voltage adjustment circuit, a common-mode inductor and multiple TVS tubes are also provided in the 485 communication circuit, and a TVS tube and a diode are also provided in the gas detector main control circuit. The TVS tube, common-mode inductor and diode can enhance the anti-electromagnetic interference capability of the gas detector main control circuit, the 485 communication circuit and the power supply voltage adjustment circuit. That is, through multiple electronic circuit protection measures, the anti-electromagnetic interference capability of the toxic gas detector when used alone is greatly improved, and the reliability and stability of the toxic gas detector are improved. When the toxic gas detector is used alone without power supply from the alarm controller or external power supply, it can accurately detect the concentration of combustible gas in real time, and can adapt to various complex interference environments, thereby improving the user experience.

[0034] like Figure 2-Figure 3As shown, the main control circuit of the gas detector is provided with a detector main control chip U5, a crystal oscillator X1, a magnetic bead B1, a magnetic bead B2, a capacitor C14, a capacitor C16 and a capacitor C18, wherein the model of the detector main control chip U5 is STM32F103C8T6, and the detector main control chip U5 has 48 pins. The first pin of the detector main control chip U5 is connected to the output end of the power supply voltage adjustment circuit, the 31st, 29th and 30th pins of the detector main control chip U5 are connected to the input end of the 485 communication circuit, the 11th and 46th pins of the detector main control chip U5 are connected to the input end of the sound and light prompt circuit, and the 16th, 15th, 14th and 28th pins of the detector main control chip U5 are connected to the input end of the sound and light prompt circuit. The pin is connected to the input end of the LED status display circuit, the 20th, 19th, and 18th pins of the detector main control chip U5 are connected to the input end of the digital display screen, the 5th and 6th pins of the detector main control chip U5 are connected to the sensor acquisition control circuit, the 5th pin of the detector main control chip U5 is connected to one end of the magnetic bead B1, the 6th pin of the detector main control chip U5 is connected to one end of the magnetic bead B2 and one end of the capacitor C18, the other end of the magnetic bead B1 is connected to one end of the capacitor C14 and one end of the crystal oscillator X1, the other end of the magnetic bead B2 is connected to one end of the capacitor C16 and the other end of the crystal oscillator X1, the other end of the capacitor C14, the other end of the capacitor C16, and the other end of the capacitor C18 are grounded. Figure 4-Figure 5As shown, the main control circuit of the gas detector is also provided with a current loop chip U11, a transistor Q1, a field effect transistor Q2, a capacitor C19, a resistor R17, a diode D12, a TVS tube D11, a relay K1 and a transistor Q3. Among them, the model of the current loop chip U11 is XTR111. The current loop chip U11 has 10 pins. The 4th pin of the current loop chip U11 is connected to the 4th pin of the detector main control chip U5. The 6th pin of the current loop chip U11 can receive external AD digital signals. The 2nd pin of the current loop chip U11 is connected to the emitter of the transistor. The 3rd pin of the current loop chip U11 is connected to the collector of the transistor and the gate of the field effect transistor Q2. The base of the tube is connected to the source of the field effect tube Q2, the drain of the field effect tube Q2 is connected to one end of the capacitor C19 and one end of the resistor R17, the other end of the resistor R17 is connected to the positive electrode of the diode D12, the cathode of the diode D12 is connected to one end of the TVS tube D11, the cathode of the diode D12 can output a current signal, the other end of the TVS tube D11 and the other end of the capacitor C19 are grounded; the relay K1 has 5 pins, the second pin of the relay K1 is connected to the collector of the transistor Q3, the base of the transistor Q3 is connected to the third pin of the detector main control chip U5, the emitter of the transistor Q3 is grounded, and the 3rd, 4th and 5th pins of the relay K1 can be connected to other external electronic devices. In this embodiment, the gas detector's main control circuit is used to control the sensor acquisition control circuit to control the gas signal acquisition circuit and the temperature signal acquisition circuit to collect the concentration and temperature of combustible gas. It is also used to control the sound and light prompt circuit to issue alarm prompts, the LED status display circuit to display various statuses, and the digital display screen to display various information. It is also used to communicate with external devices via a 485 communication circuit. Crystal oscillator X1 provides the clock frequency for the detector's main control chip U5. Capacitors C14 and C16 serve as starting capacitors, magnetic beads B1 and B2 can filter noise signals in the clock frequency signal, and capacitor C18 can bypass noise signals in the clock frequency signal. Compared with ordinary crystal oscillator circuits, this circuit structure provides higher clock frequency accuracy for the entire circuit. Current loop chip U11 uses the AD digital signal at its input to control the output of a 4mA-20mA current signal. TVS diode D11 provides high-voltage protection, diode D12 protects against backflow, resistor R17 provides current limiting, and capacitor C19 provides filtering. This circuit structure, a key module in toxic gas detectors, enables them to output a stable, reliable, and high-precision 4mA-20mA current. Relay K1 provides an interface for external linkage devices (fans, solenoid valves, etc.).

[0035] like Figure 6-Figure 7As shown, the power supply voltage adjustment circuit is provided with a voltage regulator chip U1, a voltage regulator chip U2, a voltage regulator chip U3, a fuse resistor F1, a diode D10, a TVS tube D1, a common mode inductor L1, a capacitor C4, an inductor L2, a capacitor C7, a capacitor C8 and a capacitor C9. Among them, the model of the voltage regulator chip U1 is LM2842, the model of the voltage regulator chip U2 is AMS1117-3V3, and the model of the voltage regulator chip U3 is TPS76333DBV. The voltage regulator chip U1 has 6 pins, the voltage regulator chip U2 has 3 pins, and the voltage regulator chip U3 has 5 pins. The 4th pin of the voltage regulator chip U1 is connected to the output end of the common mode inductor L1, one end of the capacitor C4, and one end of the capacitor C7. The input end of the common mode inductor L1 is connected to one end of the TVS tube D1 and one end of the fuse resistor F1. The other end of the fuse resistor F1 is connected to the cathode of the diode D10, and the anode of the diode D10 is connected to a 24V The DC power supply is connected to the sixth pin of the voltage regulator chip U1, which is connected to one end of the inductor L2. The other end of the inductor L2 is connected to one end of the capacitor C8, one end of the capacitor C9, the third pin of the voltage regulator chip U2, and the first pin of the voltage regulator chip U3. The second pin of the voltage regulator chip U2 is connected to the first pin of the detector main control chip U5. The fifth pin of the voltage regulator chip U3 is connected to the sensor voltage adjustment circuit, the sensor acquisition control circuit, the temperature signal acquisition circuit, and the gas signal acquisition circuit. The other end of the TVS diode D1, the other end of the capacitor C7, the other end of the capacitor C8, and the other end of the capacitor C9 are grounded. The sensor voltage adjustment circuit includes a voltage regulator chip U4, model TLV376IDBVR. The voltage regulator chip U4 has five pins. Pins 3 and 5 of the voltage regulator chip U4 are connected to pin 5 of the voltage regulator chip U3. Pin 4 of the voltage regulator chip U4 is connected to the gas signal acquisition circuit. In this embodiment, the power supply voltage adjustment circuit is used to power the temperature signal acquisition circuit, the sensor voltage adjustment circuit, the sensor acquisition control circuit, and the gas detector main control circuit. The power supply voltage regulation circuit consists of three sub-modules. The first sub-circuit module, consisting of voltage regulator chip U1 and peripheral circuitry, steps down the 24V DC power supply to a 6V DC power supply, V6.0 in the diagram. The second sub-circuit module, consisting of voltage regulator chip U2 and peripheral circuitry, steps down the 6V DC power supply to a 3.3V DC power supply, V3.3 in the diagram. The third sub-circuit module, consisting of voltage regulator chip U3 and peripheral circuitry, steps down the 6V DC power supply to another 3.3V DC power supply, SV3.3 in the diagram.Among them, diode D10 prevents reverse connection of the power supply, fuse resistor F1 acts as a fuse to protect the circuit when the current is too large, and TVS tube D1 can release transient high voltage, such as surge voltage; common-mode inductor L1 can suppress common-mode / differential-mode interference signals in the current, enhancing the ability to resist electromagnetic interference; capacitors C4, C10 and the ground form a Y-type circuit, which can also effectively filter out differential-mode interference signals in the current signal; voltage regulator chip U1 uses the high-precision and high-stability model LM2842; capacitors C7, C8, and C9 are filter capacitors. After multiple protections composed of electronic components, the entire power supply voltage adjustment circuit has a high ability to resist electromagnetic interference, providing a stable and reliable power supply for the subsequent circuits.

[0036] like Figure 8 As shown, the sensor acquisition control circuit includes a sensor acquisition control chip U13. The model of sensor acquisition control chip U13 is STM32C011F4U6TR. Sensor acquisition control chip U13 has 20 pins. Pin 2 of sensor acquisition control chip U13 is connected to pin 5 of voltage regulator chip U3. Pins 1 and 20 of sensor acquisition control chip U13 are respectively connected to pins 6 and 5 of detector main control chip U5. Pin 6 of sensor acquisition control chip U13 is connected to the gas signal acquisition circuit, and pin 5 of sensor acquisition control chip U13 is connected to the temperature signal acquisition circuit. In this embodiment, the sensor acquisition control circuit is used to control the gas signal acquisition circuit to acquire combustible gas concentration signals and the temperature signal acquisition circuit to acquire temperature signals.

[0037] like Figure 9 As shown, the gas signal acquisition circuit includes an operational amplifier U14A, resistors R12, R13, and R14, an inductor L3, and a capacitor C17. The non-inverting input of operational amplifier U14A is connected to one end of resistor R14, the other end of which is connected to pin 4 of the voltage regulator chip U4. The inverting input of operational amplifier U14A is connected to one end of resistor R13, the other end of which is connected to one end of inductor L3, the other end of which is connected to a toxic gas acquisition sensor. The output of operational amplifier U14A is connected to one end of resistor R12, the other end of which is connected to pin 6 of the sensor acquisition control chip U13. In this embodiment, the gas signal acquisition circuit is used to convert the concentration value signal of the detected gas into an electrical signal in real time according to the control instructions of the sensor acquisition control circuit, and output it to the sensor acquisition control circuit.

[0038] like Figure 10As shown, the temperature signal acquisition circuit includes a temperature signal acquisition chip U15 and a capacitor C12. The model of temperature signal acquisition chip U15 is TMP235A2DBZR. Temperature signal acquisition chip U15 has three pins. Pin 1 of temperature signal acquisition chip U15 is connected to pin 5 of voltage regulator chip U3 and one end of capacitor C12. Pin 2 of temperature signal acquisition chip U15 is connected to pin 5 of sensor acquisition control chip U13. Pin 3 of temperature signal acquisition chip U15 and the other end of capacitor C12 are grounded. In this embodiment, the temperature signal acquisition circuit is used to collect ambient temperature in real time according to control instructions from the sensor acquisition control circuit, convert it into a digital signal, and output it to the sensor acquisition control circuit.

[0039] like Figure 11 As shown, the 485 communication circuit is provided with a 485 communication chip U6, a common-mode inductor L6, a TVS tube D7 and a TVS tube D9, wherein the 485 communication chip U6 is provided with 8 pins, and the model of the 485 communication chip U6 is SN65HVD72. The 1st, 3rd and 4th pins of the 485 communication chip U6 are respectively connected to the 31st, 29th and 30th pins of the detector main control chip U5, the 8th pin of the 485 communication chip U6 is connected to the 2nd pin of the voltage regulator chip U2, the 6th and 7th pins of the 485 communication chip U6 are connected to one end of the common-mode inductor L6, the other end of the common-mode inductor L6 can be connected to an external 485 communication device, the other end of the common-mode inductor L6 is also connected to the negative pole of the TVS tube D7 and the negative pole of the TVS tube D9, and the positive pole of the TVS tube D7 and the positive pole of the TVS tube D9 are grounded. In this embodiment, the 485 communication chip U6 uses the SN65HVD72 model with strong anti-interference ability; resistors R20, R22, and R24 play a current limiting role; the common-mode inductor L6 plays a role in filtering out interference signals; resistor R21 pulls down the communication signal; resistor R25 pulls up the communication signal; capacitors C26 and C27 play a filtering role; TVS tubes D7, D8, and D9 can release transient high-voltage noise / interference signals in the communication signal. The advantage of this circuit structure is that it can improve the reliability and stability of the communication signal.

[0040] like Figure 12As shown, the sound and light prompt circuit is provided with a transistor Q4, a loudspeaker prompt interface J6, a transistor Q5 and a light prompt interface J7, wherein the base of the transistor Q4 is connected to the 11th pin of the detector main control chip U5, the collector of the transistor Q4 is connected to the input end of the loudspeaker prompt interface J6, the output end of the loudspeaker prompt interface J6 can be connected to an external loudspeaker, the emitter of the transistor Q4 is grounded, the base of the transistor Q5 is connected to the 46th pin of the detector main control chip U5, the collector of the transistor Q5 is connected to the input end of the light prompt interface J7, the output end of the light prompt interface J7 can be connected to an external light-emitting LED lamp, and the emitter of the transistor Q5 is grounded; L The ED status display circuit is provided with a light-emitting diode D1, a light-emitting diode D2, a light-emitting diode D3 and a light-emitting diode D4, among which the positive pole of the light-emitting diode D1, the positive pole of the light-emitting diode D2, the positive pole of the light-emitting diode D3 and the positive pole of the light-emitting diode D4 are connected to the 2nd pin of the voltage regulator chip U2, the cathode of the light-emitting diode D1 is connected to the 16th pin of the detector main control chip U5, the cathode of the light-emitting diode D2 is connected to the 15th pin of the detector main control chip U5, the cathode of the light-emitting diode D3 is connected to the 14th pin of the detector main control chip U5, and the cathode of the light-emitting diode D4 is connected to the 28th pin of the detector main control chip U5. In this embodiment, the sound and light prompt circuit is divided into a sound alarm sub-module and a light alarm sub-module. The sound alarm sub-module is composed of a transistor Q4 and a peripheral circuit, which provides a sound alarm function for the toxic gas detector; the light alarm sub-module is composed of a transistor Q5 and a peripheral circuit, which provides a light source alarm function for the toxic gas detector. The sound and light module is a warning when the detector detects different gas concentrations; the LED status display circuit is used to indicate the operating status of the toxic gas detector. For example, the red light-emitting diode D1 is on to indicate that the power supply is normal, and the yellow light-emitting diode D3 is on to indicate an operating failure.

[0041] As can be seen from the above, the present invention provides a toxic gas detector control circuit capable of resisting electromagnetic interference. By arranging a power supply voltage adjustment circuit, a sensor voltage adjustment circuit, a gas detector main control circuit, a sensor acquisition control circuit, a gas signal acquisition circuit, a temperature signal acquisition circuit, a 485 communication circuit, an audio-visual prompt circuit, an LED status display circuit and a digital display screen that cooperate with each other in the toxic gas detector control circuit capable of resisting electromagnetic interference, a TVS tube, a common-mode inductor and a diode are provided in the power supply voltage adjustment circuit, a common-mode inductor and multiple TVS tubes are also provided in the 485 communication circuit, a TVS tube and a diode are also provided in the gas detector main control circuit, and a T VS tubes, common-mode inductors, and diodes can enhance the anti-electromagnetic interference capability of the gas detector's main control circuit, 485 communication circuit, and power supply voltage adjustment circuit. That is, through multiple electronic circuit protection measures, the anti-electromagnetic interference capability of the toxic gas detector when used alone is greatly improved, and the reliability and stability of the toxic gas detector are improved. When the toxic gas detector is used alone without power supply from the alarm controller or external power supply, it can accurately detect the concentration of combustible gas in real time, and can adapt to various complex interference environments, thereby improving the user experience and solving the problem of poor anti-electromagnetic interference capability and prone to failure of toxic gas detectors in the existing technology when used alone.

[0042] The specific implementation manner described above is a preferred implementation manner of the present invention, and is not intended to limit the specific implementation scope of the present invention. The scope of the present invention includes but is not limited to this specific implementation manner. All equivalent changes made in accordance with the present invention are within the protection scope of the present invention.

Claims

1. A toxic gas detector control circuit capable of resisting electromagnetic interference, characterized in that: It includes a power supply voltage adjustment circuit, a sensor voltage adjustment circuit, a gas detector main control circuit, a sensor acquisition control circuit, a gas signal acquisition circuit, a temperature signal acquisition circuit, a 485 communication circuit, an audio-visual prompt circuit, an LED status display circuit and a digital display screen. The input end of the power supply voltage adjustment circuit is connected to a 24V DC power supply. The output end of the power supply voltage adjustment circuit is connected to the temperature signal acquisition circuit, the gas signal acquisition circuit, the sensor voltage adjustment circuit, the sensor acquisition control circuit and the gas detector main control circuit for power supply. The output end of the sensor voltage adjustment circuit is connected to the gas signal acquisition circuit for power supply. The output end of the gas detector main control circuit is connected to the input end of the 485 communication circuit, the input end of the audio-visual prompt circuit, the input end of the LED status display circuit and the input end of the digital display screen for control. The gas detector main control circuit is also connected to the sensor acquisition control circuit for communication. The sensor acquisition control circuit is connected to the gas signal acquisition circuit for power supply. The collecting circuit and the temperature signal acquisition circuit are controlled and connected. The gas detector main control circuit is provided with a current loop module and a relay module. The gas signal acquisition circuit is provided with a toxic gas acquisition sensor. The gas signal acquisition circuit can collect the concentrations of carbon monoxide, hydrogen sulfide, ammonia and sulfur dioxide gases. The power supply voltage adjustment circuit is provided with a TVS tube, a common-mode inductor and a diode. The 485 communication circuit is also provided with a common-mode inductor and multiple TVS tubes. The gas detector main control circuit is also provided with a TVS tube and a diode. The TVS tube, common-mode inductor and diode can improve the anti-electromagnetic interference capability of the gas detector main control circuit, the 485 communication circuit and the power supply voltage adjustment circuit.

2. The electromagnetic interference resistant toxic gas detector control circuit according to claim 1, characterized in that: The gas detector main control circuit is provided with a detector main control chip U5, a crystal oscillator X1, a magnetic bead B1, a magnetic bead B2, a capacitor C14, a capacitor C16 and a capacitor C18. The detector main control chip U5 is provided with 48 pins. The 1st pin of the detector main control chip U5 is connected to the output end of the power supply voltage adjustment circuit, the 31st, 29th and 30th pins of the detector main control chip U5 are connected to the input end of the 485 communication circuit, the 11th and 46th pins of the detector main control chip U5 are connected to the input end of the sound and light prompt circuit, the 16th, 15th, 14th and 28th pins of the detector main control chip U5 are connected to the input end of the LED status display circuit, and the detector main Pins 20, 19, and 18 of the control chip U5 are connected to the input end of the digital display screen, pins 5 and 6 of the detector main control chip U5 are connected to the sensor acquisition control circuit, pin 5 of the detector main control chip U5 is connected to one end of the magnetic bead B1, pin 6 of the detector main control chip U5 is connected to one end of the magnetic bead B2 and one end of the capacitor C18, the other end of the magnetic bead B1 is connected to one end of the capacitor C14 and one end of the crystal oscillator X1, the other end of the magnetic bead B2 is connected to one end of the capacitor C16 and the other end of the crystal oscillator X1, the other end of the capacitor C14, the other end of the capacitor C16, and the other end of the capacitor C18 are grounded.

3. The electromagnetic interference resistant toxic gas detector control circuit according to claim 2, characterized in that: The main control circuit of the gas detector is also provided with a current loop chip U11, a transistor Q1, a field effect transistor Q2, a capacitor C19, a resistor R17, a diode D12, a TVS tube D11, a relay K1 and a transistor Q3, wherein the current loop chip U11 is provided with 10 pins, the 4th pin of the current loop chip U11 is connected to the 4th pin of the detector main control chip U5, the 6th pin of the current loop chip U11 can receive an external AD digital signal, the 2nd pin of the current loop chip U11 is connected to the emitter of the transistor, the 3rd pin of the current loop chip U11 is connected to the collector of the transistor and the gate of the field effect transistor Q2, and the base of the transistor is connected to the source of the field effect transistor Q2 The drain of the field effect tube Q2 is connected to one end of the capacitor C19 and one end of the resistor R17, the other end of the resistor R17 is connected to the positive electrode of the diode D12, the cathode of the diode D12 is connected to one end of the TVS tube D11, the negative electrode of the diode D12 can output a current signal, the other end of the TVS tube D11 and the other end of the capacitor C19 are grounded; the relay K1 is provided with 5 pins, the second pin of the relay K1 is connected to the collector of the transistor Q3, the base of the transistor Q3 is connected to the third pin of the detector main control chip U5, the emitter of the transistor Q3 is grounded, and the 3rd, 4th and 5th pins of the relay K1 can be connected to other external electronic devices.

4. The electromagnetic interference resistant toxic gas detector control circuit according to claim 3, characterized in that: The power supply voltage adjustment circuit is provided with a voltage stabilizing chip U1, a voltage stabilizing chip U2, a voltage stabilizing chip U3, a fuse resistor F1, a diode D10, a TVS tube D1, a common mode inductor L1, a capacitor C4, an inductor L2, a capacitor C7, a capacitor C8 and a capacitor C9, wherein the voltage stabilizing chip U1 is provided with 6 pins, the voltage stabilizing chip U2 is provided with 3 pins, and the voltage stabilizing chip U3 is provided with 5 pins. The 4th pin of the voltage stabilizing chip U1 is connected to the output end of the common mode inductor L1, one end of the capacitor C4, and one end of the capacitor C7. The input end of the common mode inductor L1 is connected to one end of the TVS tube D1 and one end of the fuse resistor F1. The other end of the fuse resistor F1 is connected to the cathode of the diode D10, and the anode of the diode D10 is connected to a 24V DC power supply, the 6th pin of the voltage stabilizing chip U1 is connected to one end of the inductor L2, the other end of the inductor L2 is connected to one end of the capacitor C8, one end of the capacitor C9, the 3rd pin of the voltage stabilizing chip U2, and the 1st pin of the voltage stabilizing chip U3, the 2nd pin of the voltage stabilizing chip U2 is connected to the 1st pin of the detector main control chip U5 for power supply, the 5th pin of the voltage stabilizing chip U3 is connected to the sensor voltage adjustment circuit, the sensor acquisition control circuit, the temperature signal acquisition circuit, and the gas signal acquisition circuit for power supply, the other end of the TVS tube D1, the other end of the capacitor C7, the other end of the capacitor C8, and the other end of the capacitor C9 are grounded; a voltage stabilizing chip U4 is provided in the sensor voltage adjustment circuit, and the voltage stabilizing chip U4 is provided with 5 pins, the 3rd and 5th pins of the voltage stabilizing chip U4 are connected to the 5th pin of the voltage stabilizing chip U3, and the 4th pin of the voltage stabilizing chip U4 is connected to the gas signal acquisition circuit for power supply.

5. The electromagnetic interference resistant toxic gas detector control circuit according to claim 4, characterized in that: A sensor acquisition control chip U13 is provided in the sensor acquisition control circuit. The sensor acquisition control chip U13 has 20 pins. The second pin of the sensor acquisition control chip U13 is connected to the fifth pin of the voltage stabilizing chip U3. The first and 20 pins of the sensor acquisition control chip U13 are respectively connected to the sixth and fifth pins of the detector main control chip U5. The sixth pin of the sensor acquisition control chip U13 is controlled and connected to the gas signal acquisition circuit. The fifth pin of the sensor acquisition control chip U13 is controlled and connected to the temperature signal acquisition circuit.

6. The electromagnetic interference resistant toxic gas detector control circuit according to claim 5, characterized in that: The gas signal acquisition circuit is provided with an operational amplifier U14A, a resistor R12, a resistor R13, a resistor R14, an inductor L3 and a capacitor C17. The non-inverting input terminal of the operational amplifier U14A is connected to one end of the resistor R14, and the other end of the resistor R14 is connected to the 4th pin of the voltage regulator chip U4. The inverting input terminal of the operational amplifier U14A is connected to one end of the resistor R13, and the other end of the resistor R13 is connected to one end of the inductor L3. The other end of the inductor L3 is connected to a toxic gas acquisition sensor. The output terminal of the operational amplifier U14A is connected to one end of the resistor R12, and the other end of the resistor R12 is connected to the 6th pin of the sensor acquisition control chip U13.

7. The electromagnetic interference resistant toxic gas detector control circuit according to claim 6, characterized in that: The temperature signal acquisition circuit is provided with a temperature signal acquisition chip U15 and a capacitor C12. The temperature signal acquisition chip U15 is provided with three pins. The first pin of the temperature signal acquisition chip U15 is connected to the fifth pin of the voltage stabilizing chip U3 and one end of the capacitor C12. The second pin of the temperature signal acquisition chip U15 is connected to the fifth pin of the sensor acquisition control chip U13. The third pin of the temperature signal acquisition chip U15 and the other end of the capacitor C12 are grounded.

8. The electromagnetic interference resistant toxic gas detector control circuit according to claim 7, characterized in that: The 485 communication circuit is provided with a 485 communication chip U6, a common-mode inductor L6, a TVS tube D7 and a TVS tube D9, wherein the 485 communication chip U6 is provided with 8 pins, the 1st, 3rd and 4th pins of the 485 communication chip U6 are respectively connected to the 31st, 29th and 30th pins of the detector main control chip U5, the 8th pin of the 485 communication chip U6 is connected to the 2nd pin of the voltage stabilizing chip U2, the 6th and 7th pins of the 485 communication chip U6 are connected to one end of the common-mode inductor L6, the other end of the common-mode inductor L6 can be connected to an external 485 communication device, the other end of the common-mode inductor L6 is also connected to the negative pole of the TVS tube D7 and the negative pole of the TVS tube D9, and the positive pole of the TVS tube D7 and the positive pole of the TVS tube D9 are grounded.

9. The electromagnetic interference resistant toxic gas detector control circuit according to claim 8, characterized in that: The sound and light prompt circuit is provided with a transistor Q4, a loudspeaker prompt interface J6, a transistor Q5 and a light prompt interface J7, wherein the base of the transistor Q4 is connected to the 11th pin of the detector main control chip U5, the collector of the transistor Q4 is connected to the input end of the loudspeaker prompt interface J6, the output end of the loudspeaker prompt interface J6 can be connected to an external speaker, the emitter of the transistor Q4 is grounded, the base of the transistor Q5 is connected to the 46th pin of the detector main control chip U5, the collector of the transistor Q5 is connected to the input end of the light prompt interface J7, the output end of the light prompt interface J7 can be connected to an external light-emitting LED lamp, and the emitter of the transistor Q5 is grounded; the LE The D state display circuit is provided with a light-emitting diode D1, a light-emitting diode D2, a light-emitting diode D3 and a light-emitting diode D4, wherein the positive pole of the light-emitting diode D1, the positive pole of the light-emitting diode D2, the positive pole of the light-emitting diode D3 and the positive pole of the light-emitting diode D4 are connected to the 2nd pin of the voltage regulator chip U2, the negative pole of the light-emitting diode D1 is connected to the 16th pin of the detector main control chip U5, the negative pole of the light-emitting diode D2 is connected to the 15th pin of the detector main control chip U5, the negative pole of the light-emitting diode D3 is connected to the 14th pin of the detector main control chip U5, and the negative pole of the light-emitting diode D4 is connected to the 28th pin of the detector main control chip U5.

10. The electromagnetic interference resistant toxic gas detector control circuit according to claim 9, characterized in that: The model of the detector main control chip U5 is STM32F103C8T6, the model of the current loop chip U11 is XTR111, the model of the voltage regulator chip U1 is LM2842, the model of the voltage regulator chip U2 is AMS1117-3V3, the model of the voltage regulator chip U3 is TPS76333DBV, the model of the voltage regulator chip U4 is TLV376IDBVR, the model of the sensor acquisition control chip U13 is STM32C011F4U6TR, the model of the temperature signal acquisition chip U15 is TMP235A2DBZR, and the model of the 485 communication chip U6 is SN65HVD72.

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