Light source control system and gas analyzer using same

Abstract

The utility model relates to the technical field of gas analysis, in particular to a light source control system and a gas analyzer applying the light source control system, and the light source control system comprises a light intensity detection module, a first controller module, a current detection module, a second controller module and a power supply module, and the second controller compares the lamp current signal with the first control signal and then outputs a second control signal for performing closed-loop control to stabilize the light intensity of the light-emitting module to the power supply module. According to the utility model, light intensity stability of the light-emitting module is realized through closed-loop control based on zinc lamp light intensity, real-time control of the light-emitting module can be realized, and meaningless waste of the service life of the light-emitting module caused by the fact that the light-emitting module cannot be used due to too fast light intensity attenuation at the initial working stage can be avoided; and meanwhile, self-adaptive adjustment of light-emitting modules with different batches and performances can be realized, pre-aging is not needed, and the labor intensity of assembling and debugging personnel and the later equipment maintenance cost are greatly reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of gas analysis, in particular to a light source control system and a gas analyzer using the same. Background Art

[0002] Pollutants, such as sulfur dioxide, are typical acidic gases that, when combined with water vapor, form acid rain, damaging the ecological environment and even endangering human health. Real-time monitoring of sulfur dioxide concentrations in the atmosphere allows for timely understanding of pollution conditions and facilitates pollution control efforts. The existing method of detecting polluted gases generally adopts a gas analyzer, which can detect the polluted gas content in the ppb~ppm level through ultraviolet fluorescence method and weak signal processing technology. In order to maintain a high detection accuracy, a highly stable zinc lamp light source is required. The existing zinc lamp light source generally adopts constant current open-loop control. Under this driving mode, the light intensity of a new zinc lamp light source will drop rapidly in the initial period of time during use, which may easily cause the measured concentration value of the gas analyzer to drift. After a certain period of use, the light intensity decay will reach a relatively slow speed, and it can only be used for instrument detection. Therefore, there will be a certain aging time, which will cause unnecessary waste of its service life. At the same time, due to the individual performance differences of each zinc lamp light source, the degree of light intensity decay is different, and each zinc lamp light source needs to be debugged separately. In order to compensate for the gas measurement concentration value algorithm under the state of light intensity decay, it takes a lot of manpower and time. Utility Model Content

[0003] The technical problem to be solved by the present invention is that the light intensity of the existing zinc lamp light source will gradually decay under the driving mode, resulting in a long aging time, which wastes the service life during the aging time. It needs to be debugged separately for use, which is time-consuming and labor-intensive. At the same time, after the light intensity of the zinc lamp decays, it needs to be calibrated frequently to maintain the gas measurement accuracy, resulting in high subsequent maintenance costs.

[0004] In order to solve the above technical problems, the first aspect of the present invention adopts the following technical solution: a light source control system, comprising:

[0005] A light intensity detection module, configured to detect the light intensity of the corresponding light emitting module, convert the light into a voltage signal in proportion, and output a light intensity detection signal, wherein the signal output end of the light intensity detection module is connected to the signal input end of the first controller module;

[0006] a first controller module, configured to compare the light intensity detection signal with the light intensity setting signal and output a first control signal, wherein the signal output terminal of the first controller module is connected to the signal input terminal of the second controller module;

[0007] a current detection module, configured to detect the operating current of the light-emitting module and output a lamp current signal; wherein the detection terminal of the current detection module is connected to the light-emitting module, and the signal output terminal of the current detection module is connected to the signal input terminal of the second controller module;

[0008] a second controller module, configured to compare the lamp current signal with the first control signal or a reference voltage and output a second control signal for performing a compensation output, wherein a signal output terminal of the second controller module is connected to a control terminal of the power module;

[0009] a power module, configured to supply power and perform compensation output according to a second control signal;

[0010] The second controller outputs a second control signal for performing closed-loop control to stabilize the light intensity of the light-emitting module to the power module after comparing the lamp current signal with the first control signal.

[0011] When the utility model is working, the light intensity of the light-emitting module is stabilized through closed-loop control based on the intensity of zinc lamp light, which can realize real-time control of the light-emitting module with high control accuracy, improve the stability of light intensity, and avoid the meaningless waste of the service life of the light-emitting module due to the light intensity decaying too quickly in the early stage of operation. At the same time, it can also realize adaptive adjustment of light-emitting modules with different performance batches without the need for pre-aging, which greatly reduces the labor intensity of assembly and debugging personnel and the later equipment maintenance costs.

[0012] Preferably, the light intensity detection module includes a light intensity sensor PD1, an operational amplifier U1, a resistor R1, a resistor R2, a resistor R3, a resistor R4, a capacitor C1 and a capacitor C2. The inverting input terminal of the operational amplifier U1 is connected to the first end of the light intensity sensor through the resistor R1, the second end of the light intensity sensor is grounded, the non-inverting input terminal of the operational amplifier U1 is grounded through the resistor R2, the inverting input terminal of the operational amplifier U1 is connected to the output terminal of the operational amplifier U1 through the resistor R3 and the capacitor C1 respectively, the output terminal of the operational amplifier U1 is connected to the first end of the resistor R4, the second end of the resistor R4 is connected to the signal input terminal of the first controller module and is grounded through the capacitor C2.

[0013] When the utility model is working, the light intensity sensor PD1 generates a photocurrent which is converted into a voltage signal by the operational amplifier U1 and then filtered by a low-pass filter to output a light intensity detection signal to the first controller, with high measurement accuracy and strong anti-interference ability.

[0014] Preferably, the first controller module includes an operational amplifier U2, a diode ZD2, a resistor R5, a resistor R6, a capacitor C3 and a capacitor C4, the inverting input terminal of the operational amplifier U2 is connected to the signal output terminal of the light intensity detection module through the resistor R5, the non-inverting input terminal of the operational amplifier U2 is connected to the corresponding light intensity setting signal, the inverting input terminal of the operational amplifier U2 is connected to the output terminal of the operational amplifier U2 through the capacitor C4 and is connected to the output terminal of the operational amplifier U2 through the capacitor C3 and the resistor R6, and the output terminal of the operational amplifier U2 is connected to the signal input terminal of the second controller module and is grounded through the diode ZD2.

[0015] When the utility model is working, the error comparison between the set light intensity setting signal and the light intensity detection signal output by the light intensity detection module is carried out, and the closed-loop adjustment of the light intensity signal is realized by using a proportional integral circuit, so as to facilitate the control and adjustment of the target light intensity of the light-emitting module. At the same time, the level of the output signal is limited by the diode voltage regulator clamp, so that the first control signal can be protected when the light intensity is severely attenuated or the adjustment is accidentally out of control to avoid excessive lamp current of the light-emitting module, thereby improving the safety factor.

[0016] Preferably, the current detection module includes a diode D1, a diode D2, a diode D3, a diode D4 and a resistor R7, the anode of the diode D1, the anode of the diode D4, the cathode of the diode D2 and the cathode of the diode D3 are all connected to the drive circuit in the light-emitting module, the anode of the diode D2 and the anode of the diode D3 are both grounded, and the cathode of the diode D1 and the cathode of the diode D4 are connected to the signal input end of the second controller module and grounded through the resistor R7.

[0017] Preferably, the second controller module includes an operational amplifier U3, a diode ZD1, a resistor R8, a resistor R9, a resistor R10, a capacitor C5 and a capacitor C6. The inverting input terminal of the operational amplifier U3 is connected to the output terminal of the first controller or the reference voltage signal through the resistor R9, the inverting input terminal of the operational amplifier U3 is connected to the output terminal of the operational amplifier U3 through the resistor R10 and the capacitor C6 respectively, the non-inverting input terminal of the operational amplifier U3 is connected to the signal output terminal of the current detection module through the resistor R8, the non-inverting input terminal of the operational amplifier U3 is grounded through the diode ZD1 and the capacitor C5 respectively, and the output terminal of the operational amplifier U3 is connected to the control terminal of the power supply module.

[0018] When the utility model is working, by comparing the lamp current signal and the first control signal, a second control signal for closed-loop control to stabilize the light intensity of the light-emitting module can be output, which can realize closed-loop control of the light intensity of the light-emitting module with high control accuracy and good light intensity stability. At the same time, by comparing the lamp current signal and the reference voltage, a second control signal for controlling the light-emitting module to operate at the maximum power state can be output, which facilitates the adjustment of the target light intensity of the light-emitting module according to its actual working state, and optimizes the steps of debugging the light-emitting module.

[0019] Preferably, the power supply module includes a DC voltage regulation module and an AC drive module, the control end of the DC voltage regulation module is connected to the signal output end of the second controller module, the output end of the DC voltage regulation module is connected to the input end of the AC drive module, and the output end of the AC drive module is connected to the power input end of the light-emitting module.

[0020] Preferably, the DC voltage regulation module includes a switching power supply control chip U20, an inductor L20, an inductor L21, a MOS tube Q20, a diode D20, a resistor R20, a resistor R21, a resistor R22, a resistor R23, a resistor R24, a resistor R25, a resistor R26, a capacitor C20, a capacitor C21, a capacitor C22, a capacitor C23 and a capacitor C24. The RUN port of the switching power supply control chip U20 is connected to the power supply and to the first end of the capacitor C20 through the resistor R20, and the second end of the capacitor C20 is grounded. The ITH port of the switching power supply control chip U20 is grounded through the resistor R23 and the capacitor C23, and the FB port of the switching power supply control chip U20 is connected to the power supply through the resistor R26. The first end of the resistor R25 is connected to the signal output end of the second controller module and is connected to the first end of the resistor R25. The second end of the resistor R25 is grounded. The FREQ port of the switching power supply control chip U20 is grounded through the resistor R22. The MODE / SYNC port and the INTVCC port of the switching power supply control chip U20 are both grounded through the capacitor C24. The GATE port of the switching power supply control chip U20 is connected to the gate of the MOS tube Q20 through the resistor R21. The VIN port of the switching power supply control chip U20 is connected to the power supply. The SENSE port of the switching power supply control chip U20 is connected to the first end of the inductor L20, the drain of the MOS tube Q20 and the first end of the capacitor C21. The inductor L The second end of the MOSFET Q20 is connected to the power supply, the source of the MOS transistor Q20 is grounded, the second end of the capacitor C21 is connected to the anode of the diode D20 and is grounded through the inductor L21, the cathode of the diode D20 is connected to the first end of the resistor R24 ​​and is grounded through the capacitor C22, the second end of the resistor R24 ​​is connected to the first end of the resistor R25, and the AC drive module includes a push-pull drive chip U30, a transformer T30, a MOS transistor Q30, a MOS transistor Q31, a resistor R30, a resistor R31, a resistor R32, a resistor R33 and a capacitor C30, the OUTA port of the push-pull drive chip U30 is connected to the gate of the MOS transistor Q30 through the resistor R31, and the drain of the MOS transistor Q30 is connected to the transformer The first pin of the transformer T30 is connected, the source of the MOS transistor Q30 is connected to the first end of the resistor R33, the OUTB port of the push-pull driver chip U30 is connected to the gate of the MOS transistor Q31 through the resistor R32, the drain of the MOS transistor Q31 is connected to the fifth pin of the transformer T30, the source of the MOS transistor Q31 is connected to the first end of the resistor R33, the second end of the resistor R33 is grounded, the third pin of the transformer T30 is connected to the cathode of the diode D20, the tenth pin of the transformer T30 is connected to the first end of the power input end of the light-emitting module through the resistor R30, and the sixth pin of the transformer T30 is connected to the second end of the power input end of the light-emitting module and the detection end of the current detection module.

[0021] In order to solve the above-mentioned technical problems, the second aspect of the present invention adopts the following technical solution: a gas analyzer, comprising a light-emitting module for emitting light for detection, such as the above-mentioned light source control system, and a concentration detection module for detecting the concentration of gas components. When detecting the concentration of gas components, the concentration detection module compensates the measured concentration value through light intensity calibration compensation and then outputs the actual concentration value.

[0022] When the utility model is working, by detecting and calibrating the light intensity of the light-emitting module before and after natural attenuation and the corresponding gas measurement concentration, it is possible to realize gas concentration compensation based on the light-emitting module in different attenuation states, without the need for tedious concentration calibration operations, and better maintain the stability of the gas measurement concentration of the light-emitting module under natural attenuation.

[0023] The beneficial technical effects of the utility model include:

[0024] 1. The utility model realizes the stability of the light intensity of the light-emitting module through closed-loop control based on the light intensity of zinc lamp, can realize real-time control of the light-emitting module, has high control accuracy, can improve the stability of the light intensity, and can also avoid the meaningless waste of the service life of the light-emitting module due to the rapid attenuation of the light intensity in the early stage of operation. At the same time, it can also realize adaptive adjustment of the light-emitting modules of different batches without the need for pre-aging, which greatly reduces the labor intensity of assembly and debugging personnel and the subsequent equipment maintenance costs.

[0025] 2. The utility model generates a photocurrent through the light intensity sensor PD1, converts it into a voltage signal through the operational amplifier U1, and then outputs the light intensity detection signal to the first controller through filtering by a low-pass filter. It has high measurement accuracy and strong anti-interference ability.

[0026] 3. The utility model compares the error between the set light intensity setting signal and the light intensity detection signal output by the light intensity detection module, and uses a proportional integral circuit to achieve closed-loop adjustment of the light intensity signal, which facilitates the control and adjustment of the target light intensity of the light-emitting module. At the same time, the level of the output signal is limited by the diode voltage regulator clamp, which can protect the first control signal to avoid excessive lamp current of the light-emitting module when the light intensity is severely attenuated or the adjustment is accidentally out of control, thereby improving the safety factor.

[0027] 4. The utility model can output a second control signal for closed-loop control to stabilize the light intensity of the light-emitting module by comparing the lamp current signal with the first control signal, thereby realizing closed-loop control of the light intensity of the light-emitting module with high control accuracy and good light intensity stability. At the same time, the utility model can also output a second control signal for controlling the light-emitting module to operate at the maximum power state by comparing the lamp current signal with the reference voltage, thereby facilitating adjustment of the target light intensity according to the actual working state of the light-emitting module and optimizing the steps of debugging the light-emitting module.

[0028] 5. The present invention can set the target light intensity value according to the actual working state of the light-emitting module, thereby improving the utilization rate of the light-emitting module. At the same time, it stabilizes the light intensity of the light-emitting module through closed-loop control with high control accuracy. It can timely adjust the light intensity of the light-emitting module to compensate for the light intensity attenuation during use, thereby improving its utilization rate in the entire working cycle.

[0029] 6. The utility model detects and calibrates the light intensity of the light-emitting module before and after natural attenuation and the corresponding gas measurement concentration, thereby realizing gas concentration compensation based on the light-emitting module in different attenuation states, without the need for tedious concentration calibration operations, and better maintaining the stability of the gas measurement concentration of the light-emitting module under natural attenuation.

[0030] Other features and advantages of the present invention will be disclosed in detail in the following specific embodiments and drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The present invention will be further described below with reference to the accompanying drawings:

[0032] Attachment Figure 1 The following is a workflow diagram of a light source control system;

[0033] Attachment Figure 2 This is the circuit structure diagram of the light intensity detection module;

[0034] Attachment Figure 3 is a circuit structure diagram of the first controller module;

[0035] Attachment Figure 4 This is the circuit structure diagram of the current detection module;

[0036] Attachment Figure 5 is a circuit structure diagram of the second controller module;

[0037] Attachment Figure 6 This is the circuit structure diagram of the DC voltage regulation module;

[0038] Attachment Figure 7 This is the circuit structure diagram of the AC drive module. DETAILED DESCRIPTION

[0039] The following is an explanation and description of the technical solutions of the embodiments of the present invention in conjunction with the drawings of the embodiments of the present invention, but the following embodiments are only preferred embodiments of the present invention and are not exhaustive. Based on the embodiments in the embodiments, other embodiments obtained by those skilled in the art without creative work are all within the scope of protection of the present invention.

[0040] In the following description, terms such as "inside", "outside", "up", "down", "left", "right", etc. that indicate directions or positional relationships are only used to facilitate the description of the embodiments and simplify the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operate in a specific direction. Therefore, they should not be understood as limiting the present invention.

[0041] Example 1:

[0042] Please see the attached Figure 1 This embodiment discloses a light source control system, a debugging method thereof, and a gas analyzer using the same, including:

[0043] The light intensity detection module 1 is used to detect the light intensity of the corresponding light emitting module, that is, the zinc lamp light source, which can of course also be any other suitable light source, convert the light into a voltage signal in proportion and output a light intensity detection signal. The signal output end of the light intensity detection module 1 is connected to the signal input end of the first controller module 2;

[0044] The first controller module 2 is used to compare the light intensity detection signal with the light intensity setting signal and output a first control signal, and the signal output end of the first controller module 2 is connected to the signal input end of the second controller module 4;

[0045] The current detection module 3 is used to detect the working current of the light-emitting module and output a lamp current signal. The detection end of the current detection module 3 is connected to the light-emitting module, and the signal output end of the current detection module 3 is connected to the signal input end of the second controller module 4;

[0046] The second controller module 4 is used to compare the lamp current signal with the first control signal or the reference voltage and output a second control signal for compensation output. The signal output terminal of the second controller module 4 is connected to the control terminal of the power module 5;

[0047] A power supply module 5, configured to supply power and perform compensation output according to a second control signal;

[0048] The second controller compares the lamp current signal with the first control signal and then outputs a second control signal to the power supply module 5 for closed-loop control to stabilize the light intensity of the light-emitting module.

[0049] When this embodiment is working, the light intensity of the light-emitting module is stabilized through closed-loop control based on the light intensity of the zinc lamp, which can realize real-time control of the light-emitting module with high control accuracy, improve the stability of the light intensity, and avoid the meaningless waste of the service life of the light-emitting module due to the rapid attenuation of the light intensity in the early stage of operation. At the same time, it can also realize adaptive adjustment of the performance of light-emitting modules of different batches without the need for pre-aging, which greatly reduces the labor intensity of assembly and debugging personnel and the subsequent equipment maintenance costs.

[0050] Please see the attached Figure 1 To the attached Figure 7 Preferably, the power supply module 5 includes a DC voltage regulating module 51 and an AC driving module 52, the control end of the DC voltage regulating module 51 is connected to the signal output end of the second controller module 4, the output end of the DC voltage regulating module 51 is connected to the input end of the AC driving module 52, and the output end of the AC driving module 52 is connected to the power input end of the light-emitting module.

[0051] In a specific implementation, the DC voltage regulation module 51 includes a switching power supply control chip U20, an inductor L20, an inductor L21, a MOS tube Q20, a diode D20, a resistor R20, a resistor R21, a resistor R22, a resistor R23, a resistor R24, a resistor R25, a resistor R26, a capacitor C20, a capacitor C21, a capacitor C22, a capacitor C23 and a capacitor C24. The RUN port of the switching power supply control chip U20 is connected to the power supply and to the first end of the capacitor C20 through the resistor R20, and the second end of the capacitor C20 is grounded. The ITH port of the switching power supply control chip U20 is grounded through the resistor R23 and the capacitor C23. The FB port of the power supply control chip U20 is connected to the signal output end of the second controller module 4 through the resistor R26 and is connected to the first end of the resistor R25. The second end of the resistor R25 is grounded. The FREQ port of the switching power supply control chip U20 is grounded through the resistor R22. The MODE / SYNC port and the INTVCC port of the switching power supply control chip U20 are both grounded through the capacitor C24. The GATE port of the switching power supply control chip U20 is connected to the gate of the MOS tube Q20 through the resistor R21. The VIN port of the switching power supply control chip U20 is connected to the power supply. The SENSE port of the switching power supply control chip U20 is connected to the inductor L20. The first end of the MOS tube Q20 is connected to the drain of the MOS tube Q20 and the first end of the capacitor C21. The second end of the inductor L20 is connected to the power supply. The source of the MOS tube Q20 is grounded. The second end of the capacitor C21 is connected to the anode of the diode D20 and is grounded through the inductor L21. The cathode of the diode D20 is connected to the first end of the resistor R24 ​​and is grounded through the capacitor C22. The second end of the resistor R24 ​​is connected to the first end of the resistor R25. In a specific implementation, the switching power supply control chip U20 can be set to LTC1871 or LM3481. At the same time, the SEPIC switching power supply topology is used to achieve buck-boost. When the light-emitting module is started, the back-stage AC The current driving module 52 provides high voltage, which breaks down the zinc lamp light source of the light-emitting module through the high voltage to make it enter a steady-state working state. It can also provide low voltage for the AC driving module 52 to generate a lower AC voltage. At the same time, by connecting the SENSE port of the switching power supply control chip U20 to the drain of the MOS tube Q20, the on-resistance of the MOS tube Q20 can be used as a current sampling resistor, and a current sampling resistor can be omitted, thereby reducing costs and making the circuit more compact. Preferably, the switching power supply circuit can be selected as a BUCK type, a BOOST type, a SEPIC type, or any non-isolated DC-DC power converter according to the input DC voltage.

[0052] The AC drive module 52 includes a push-pull drive chip U30, a transformer T30, a MOS transistor Q30, a MOS transistor Q31, a resistor R30, a resistor R31, a resistor R32, a resistor R33 and a capacitor C30. The OUTA port of the push-pull drive chip U30 is connected to the gate of the MOS transistor Q30 through the resistor R31, the drain of the MOS transistor Q30 is connected to the first pin of the transformer T30, and the source of the MOS transistor Q30 is connected to the first end of the resistor R33. The OUTB port of the push-pull drive chip U30 is connected to the gate of the MOS transistor Q31 through the resistor R32, the drain of the MOS transistor Q31 is connected to the fifth pin of the transformer T30, the source of the MOS transistor Q31 is connected to the first end of the resistor R33, and the second end of the resistor R33 is connected. The terminal is grounded, the third pin of the transformer T30 is connected to the cathode of the diode D20, the tenth pin of the transformer T30 is connected to the first terminal of the power input terminal of the light-emitting module through the resistor R30, and the sixth pin of the transformer T30 is connected to the second terminal of the power input terminal of the light-emitting module and the detection terminal of the current detection module 3. In a specific implementation, the output of the push-pull driver chip U30 causes the MOS tube Q30 and the MOS tube Q31 to be alternately turned on in half a cycle, so that the high-frequency transformer T30 is boosted, so that the amplitude of the AC square wave output by the secondary is proportional to the voltage of the DC voltage regulation terminal, thereby driving the light-emitting module to emit light. Preferably, the push-pull driver chip U30 can be SG3525 or TL494. Of course, any other suitable chip can also be used.

[0053] Example 2:

[0054] Please see the attached Figure 1 This embodiment provides a light source control system. The similarities with other embodiments will not be repeated here. The differences will be described in detail below with reference to the accompanying drawings.

[0055] Please see the attached Figure 1 To the attached Figure 7 In this embodiment, the light intensity detection module 1 includes a light intensity sensor PD1, an operational amplifier U1, a resistor R1, a resistor R2, a resistor R3, a resistor R4, a capacitor C1 and a capacitor C2. The inverting input terminal of the operational amplifier U1 is connected to the first terminal of the light intensity sensor through the resistor R1, the second terminal of the light intensity sensor is grounded, the non-inverting input terminal of the operational amplifier U1 is grounded through the resistor R2, the inverting input terminal of the operational amplifier U1 is connected to the output terminal of the operational amplifier U1 through the resistor R3 and the capacitor C1 respectively, the output terminal of the operational amplifier U1 is connected to the first terminal of the resistor R4, the second terminal of the resistor R4 is connected to the signal input terminal of the first controller module 2 and is grounded through the capacitor C2.

[0056] When this embodiment is working, the photocurrent generated by the light intensity sensor PD1 is converted into a voltage signal by the operational amplifier U1 and then filtered by a low-pass filter to output the light intensity detection signal to the first controller, with high measurement accuracy and strong anti-interference ability.

[0057] Preferably, the first controller module 2 includes an operational amplifier U2, a diode ZD2, a resistor R5, a resistor R6, a capacitor C3 and a capacitor C4, the inverting input terminal of the operational amplifier U2 is connected to the signal output terminal of the light intensity detection module 1 through the resistor R5, the non-inverting input terminal of the operational amplifier U2 is connected to the corresponding light intensity setting signal, the inverting input terminal of the operational amplifier U2 is connected to the output terminal of the operational amplifier U2 through the capacitor C4 and is connected to the output terminal of the operational amplifier U2 through the capacitor C3 and the resistor R6, and the output terminal of the operational amplifier U2 is connected to the signal input terminal of the second controller module 4 and is grounded through the diode ZD2.

[0058] When this embodiment is working, an error comparison is performed between the set light intensity setting signal and the light intensity detection signal output by the light intensity detection module, and a proportional integral circuit is used to implement closed-loop regulation of the light intensity signal, thereby facilitating the control and adjustment of the target light intensity of the light-emitting module. At the same time, the level of the output signal is limited by the diode voltage regulator clamp, which can protect the first control signal when the light intensity is severely attenuated or the adjustment is accidentally out of control to avoid excessive lamp current of the light-emitting module, thereby improving the safety factor.

[0059] In a specific implementation, the current detection module 3 includes a diode D1, a diode D2, a diode D3, a diode D4 and a resistor R7. The anode of the diode D1, the anode of the diode D4, the cathode of the diode D2 and the cathode of the diode D3 are all connected to the drive circuit in the light-emitting module, the anode of the diode D2 and the anode of the diode D3 are both grounded, and the cathode of the diode D1 and the cathode of the diode D4 are connected to the signal input end of the second controller module 4 and grounded through the resistor R7, thereby generating a lamp current signal through full-wave rectification.

[0060] Preferably, the second controller module 4 includes an operational amplifier U3, a diode ZD1, a resistor R8, a resistor R9, a resistor R10, a capacitor C5 and a capacitor C6. The inverting input terminal of the operational amplifier U3 is connected to the output terminal of the first controller or the reference voltage signal through the resistor R9, the inverting input terminal of the operational amplifier U3 is connected to the output terminal of the operational amplifier U3 through the resistor R10 and the capacitor C6 respectively, the non-inverting input terminal of the operational amplifier U3 is connected to the signal output terminal of the current detection module 3 through the resistor R8, the non-inverting input terminal of the operational amplifier U3 is grounded through the diode ZD1 and the capacitor C5 respectively, and the output terminal of the operational amplifier U3 is connected to the control terminal of the power supply module 5.

[0061] When this embodiment is working, by comparing the lamp current signal and the first control signal, a second control signal for closed-loop control to stabilize the light intensity of the light-emitting module can be output, thereby realizing closed-loop control of the light intensity of the light-emitting module with high control accuracy and good light intensity stability. At the same time, by comparing the lamp current signal and the reference voltage, a second control signal for controlling the light-emitting module to operate at the maximum power state can be output, thereby facilitating adjustment of the target light intensity of the light-emitting module according to its actual working state and optimizing the steps of debugging the light-emitting module.

[0062] Example 3:

[0063] This embodiment provides a light source control system. The similarities with other embodiments are not repeated here, and the differences are described in detail below.

[0064] In this embodiment, the first controller module 2 and the second controller module 4 can be configured as an ADC chip circuit for converting the collected light intensity detection signal and lamp current signal into a digital signal, a microprocessor circuit for obtaining a corresponding adjustment signal using an algorithm according to a light intensity setting value, and a DAC chip for converting the adjustment signal into a voltage signal. During operation, the power supply module 5 performs output compensation through the output voltage signal received from the DAC chip to achieve closed-loop control of the light intensity. More flexible control can be achieved through digital control. At the same time, various advanced algorithm logics such as PID / model predictive control MPC / fuzzy control can also be deployed to facilitate the detection and processing of overvoltage and overcurrent conditions.

[0065] Example 4:

[0066] This embodiment provides a debugging method for a light source control system, which uses a light source control system as described in the above embodiment, including the following steps:

[0067] S1: Initialize the light source control system and connect the light emitting module, light intensity detection module 1, first controller module 2, current detection module 3, second controller module 4 and power supply module 5;

[0068] S2: Switch the light source control system to the open-loop control mode, set the reference voltage, and use the second controller module 4 to compare the reference voltage and the lamp current signal to output a second control signal to the power supply module 5 to adjust the driving state of the light-emitting module to the maximum power state. The maximum light intensity value of the light-emitting module is calibrated by the light intensity detection module 1, and the target light intensity value is calculated according to the preset target light intensity ratio;

[0069] S3: Switch the light source control system to the closed-loop control mode, set the light intensity setting signal to the calculated target light intensity value, compare the actual light intensity value with the target light intensity value through the first controller module 2 and output a first control signal, the second controller module 4 outputs a second control signal to the power supply module 5 by comparing the second control signal and the lamp current signal to compensate for the output power, and control the actual light intensity value of the light source module to remain at the target light intensity value.

[0070] When this embodiment is working, the target light intensity value can be set according to the actual working state of the light-emitting module, which can improve the utilization rate of the light-emitting module. At the same time, the light intensity of the light-emitting module is stabilized through closed-loop control. The control accuracy is high, and the light intensity of the light-emitting module can be adjusted in time to compensate for the light intensity attenuation during use, thereby improving its utilization rate in the entire working cycle.

[0071] As a further improvement of this embodiment, in step S3, the following steps are also included: when the actual light intensity value detected by the light intensity detection module 1 is lower than the current target light intensity value and the power module output has reached the maximum power, go to step S2, which can achieve resetting the target light intensity value after the light-emitting module attenuates to a certain extent, thereby improving its utilization rate in the entire working cycle.

[0072] Embodiment 5:

[0073] This embodiment provides a gas analyzer, including a light emitting module for emitting light for detection, such as the light source control system in the above embodiment, and a concentration detection module for detecting the concentration of gas components, which is described in detail below.

[0074] In this embodiment, the concentration detection module compensates the measured concentration value through light intensity calibration compensation when detecting the concentration of gas components and then outputs the actual concentration value, which can reduce the concentration measurement error value of the light-emitting module after the light intensity attenuates. At the same time, the light intensity calibration compensation of this embodiment can also be applied to traditional constant current open-loop control analytical instruments. The light intensity of the zinc lamp will naturally decay after aging, and the light intensity compensation algorithm can also be used to reduce the error. At the same time, when the light intensity attenuation exceeds the closed-loop control range, the light intensity compensation algorithm is also needed to reduce the error.

[0075] In specific implementation, the light intensity calibration compensation adopts the following steps:

[0076] A1: Initialize the light module, perform normal concentration calibration on the gas analyzer, and record the current light intensity value I0 and the calibration concentration value C1;

[0077] A2: Adjust the light source to adjust the light intensity of the system. Set the signal to I0*M. M can be set to the attenuation ratio threshold, for example, 0.8. Record the concentration value at this time as C2.

[0078] A3: The light intensity compensation coefficient k is calculated using the following formula:

[0079] k=(C1-C2) / (0.2*I0);

[0080] A4: When the light intensity of the working light module decays, record the real-time light intensity I after decay and the gas concentration C detected at that time. The actual concentration C' is calculated using the following formula:

[0081] C'=C+(I0-I)*k+B;

[0082] Wherein: B is the intercept compensation coefficient of the preset concentration. In actual work, B can be adjusted according to the actual working environment.

[0083] The beneficial technical effects of this embodiment include: the utility model can realize gas concentration compensation based on the light-emitting module in different attenuation states by detecting and calibrating the light intensity of the light-emitting module and the corresponding gas measurement concentration before and after natural attenuation, without the need for tedious concentration calibration operations, and better maintaining the stability of the gas measurement concentration of the light-emitting module under natural attenuation.

[0084] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Those skilled in the art will understand that the present invention includes, but is not limited to, the contents described in the drawings and the above specific embodiments. Any modifications that do not deviate from the functional and structural principles of the present invention are intended to be included within the scope of the claims.

Claims

1. A light source control system, characterized in that: include: A light intensity detection module (1) is used to detect the light intensity of a corresponding light emitting module, convert the light into a voltage signal in proportion, and output a light intensity detection signal, wherein the signal output end of the light intensity detection module (1) is connected to the signal input end of the first controller module (2); A first controller module (2) is used to compare the light intensity detection signal with the light intensity setting signal and output a first control signal, wherein the signal output end of the first controller module (2) is connected to the signal input end of the second controller module (4); A current detection module (3) is used to detect the operating current of the light-emitting module when it is in operation and output a lamp current signal, wherein the detection end of the current detection module (3) is connected to the light-emitting module, and the signal output end of the current detection module (3) is connected to the signal input end of the second controller module (4); A second controller module (4) is used to compare the lamp current signal with the first control signal or a reference voltage and output a second control signal for performing a compensation output, wherein the signal output end of the second controller module (4) is connected to the control end of the power supply module (5); A power module (5) is used for supplying power and performing compensation output according to a second control signal; After comparing the lamp current signal with the first control signal, the second controller outputs a second control signal for closed-loop control to stabilize the light intensity of the light-emitting module to the power supply module (5).

2. A light source control system according to claim 1, characterized in that: The light intensity detection module (1) comprises a light intensity sensor PD1, an operational amplifier U1, a resistor R1, a resistor R2, a resistor R3, a resistor R4, a capacitor C1 and a capacitor C2, wherein the inverting input terminal of the operational amplifier U1 is connected to the first terminal of the light intensity sensor via the resistor R1, the second terminal of the light intensity sensor is grounded, the non-inverting input terminal of the operational amplifier U1 is grounded via the resistor R2, the inverting input terminal of the operational amplifier U1 is connected to the output terminal of the operational amplifier U1 via the resistor R3 and the capacitor C1 respectively, the output terminal of the operational amplifier U1 is connected to the first terminal of the resistor R4, the second terminal of the resistor R4 is connected to the signal input terminal of the first controller module (2) and is grounded via the capacitor C2.

3. The light source control system according to claim 1, characterized in that: The first controller module (2) comprises an operational amplifier U2, a diode ZD2, a resistor R5, a resistor R6, a capacitor C3 and a capacitor C4; the inverting input terminal of the operational amplifier U2 is connected to the signal output terminal of the light intensity detection module (1) via the resistor R5; the non-inverting input terminal of the operational amplifier U2 is connected to the corresponding light intensity setting signal; the inverting input terminal of the operational amplifier U2 is connected to the output terminal of the operational amplifier U2 via the capacitor C4 and is connected to the output terminal of the operational amplifier U2 via the capacitor C3 and the resistor R6; the output terminal of the operational amplifier U2 is connected to the signal input terminal of the second controller module (4) and is grounded via the diode ZD2.

4. A light source control system according to claim 1, characterized in that: The current detection module (3) comprises a diode D1, a diode D2, a diode D3, a diode D4 and a resistor R7; the anode of the diode D1, the anode of the diode D4, the cathode of the diode D2 and the cathode of the diode D3 are all connected to the drive circuit in the light emitting module; the anode of the diode D2 and the anode of the diode D3 are both grounded; the cathode of the diode D1 and the cathode of the diode D4 are connected to the signal input end of the second controller module (4) and are grounded through the resistor R7.

5. The light source control system according to claim 1, characterized in that: The second controller module (4) includes an operational amplifier U3, a diode ZD1, a resistor R8, a resistor R9, a resistor R10, a capacitor C5, and a capacitor C6. The inverting input terminal of the operational amplifier U3 is connected to the output terminal of the first controller or the reference voltage signal through the resistor R9. The inverting input terminal of the operational amplifier U3 is connected to the output terminal of the operational amplifier U3 through the resistor R10 and the capacitor C6 respectively. The non-inverting input terminal of the operational amplifier U3 is connected to the signal output terminal of the current detection module (3) through the resistor R8. The non-inverting input terminal of the operational amplifier U3 is grounded through the diode ZD1 and the capacitor C5 respectively. The output terminal of the operational amplifier U3 is connected to the control terminal of the power supply module (5).

6. A light source control system according to claim 1, characterized in that: The power supply module (5) comprises a DC voltage regulating module (51) and an AC driving module (52); the control end of the DC voltage regulating module (51) is connected to the signal output end of the second controller module (4); the output end of the DC voltage regulating module (51) is connected to the input end of the AC driving module (52); and the output end of the AC driving module (52) is connected to the power input end of the light-emitting module.

7. A light source control system according to claim 6, characterized in that: The DC voltage regulation module (51) comprises a switching power supply control chip U20, an inductor L20, an inductor L21, a MOS tube Q20, a diode D20, a resistor R20, a resistor R21, a resistor R22, a resistor R23, a resistor R24, a resistor R25, a resistor R26, a capacitor C20, a capacitor C21, a capacitor C22, a capacitor C23 and a capacitor C24, a RUN port of the switching power supply control chip U20 is connected to a power supply and to a first end of the capacitor C20 via the resistor R20, a second end of the capacitor C20 is grounded, an ITH port of the switching power supply control chip U20 is grounded via the resistor R23 and the capacitor C23, and an FB port of the switching power supply control chip U20 is connected to a second end of the capacitor C20 via the resistor R26. The signal output end of the controller module (4) is connected to the first end of the resistor R25, the second end of the resistor R25 is grounded, the FREQ port of the switching power control chip U20 is grounded through the resistor R22, the MODE / SYNC port and the INTVCC port of the switching power control chip U20 are both grounded through the capacitor C24, the GATE port of the switching power control chip U20 is connected to the gate of the MOS tube Q20 through the resistor R21, the VIN port of the switching power control chip U20 is connected to the power supply, the SENSE port of the switching power control chip U20 is connected to the first end of the inductor L20, the drain of the MOS tube Q20 and the first end of the capacitor C21, and the inductor L20 is connected to the VIN port of the switching power control chip U20. The second end of the MOSFET Q20 is connected to a power supply, the source of the MOS transistor Q20 is grounded, the second end of the capacitor C21 is connected to the anode of the diode D20 and is grounded through the inductor L21, the cathode of the diode D20 is connected to the first end of the resistor R24 ​​and is grounded through the capacitor C22, the second end of the resistor R24 ​​is connected to the first end of the resistor R25, the AC drive module (52) comprises a push-pull drive chip U30, a transformer T30, a MOS transistor Q30, a MOS transistor Q31, a resistor R30, a resistor R31, a resistor R32, a resistor R33 and a capacitor C30, the OUTA port of the push-pull drive chip U30 is connected to the gate of the MOS transistor Q30 through the resistor R31, the drain of the MOS transistor Q30 is connected to the transformer T The first pin of the transformer T30 is connected to the first pin of the MOS transistor Q30, the source of the MOS transistor Q30 is connected to the first end of the resistor R33, the OUTB port of the push-pull driver chip U30 is connected to the gate of the MOS transistor Q31 through the resistor R32, the drain of the MOS transistor Q31 is connected to the fifth pin of the transformer T30, the source of the MOS transistor Q31 is connected to the first end of the resistor R33, the second end of the resistor R33 is grounded, the third pin of the transformer T30 is connected to the cathode of the diode D20, the tenth pin of the transformer T30 is connected to the first end of the power input terminal of the light emitting module through the resistor R30, and the sixth pin of the transformer T30 is connected to the second end of the power input terminal of the light emitting module and the detection end of the current detection module (3).

8. A gas analyzer comprising a light emitting module for emitting light for detection, a light source control system according to any one of claims 1 to 7, and a concentration detection module for detecting the concentration of gas components, characterized in that: When detecting the concentration of gas components, the concentration detection module compensates the measured concentration value by light intensity calibration compensation and then outputs the actual concentration value.

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