Self-checking circuit for infrared optical detection

Abstract

The utility model discloses a self-checking circuit for infrared optical detection. The self-checking circuit comprises a light source receiving module, an operational amplifier module and a negative feedback module provided with a voltage output end, and the light source receiving module, the operational amplifier module and the negative feedback module are in circuit connection. According to the self-checking circuit for infrared optical detection disclosed by the utility model, the light source receiving module is used for receiving infrared light and converting invisible infrared light into current, the current is converted into a voltage signal changing along with the current through the cooperation of the operational amplifier module and the negative feedback module, and finally the voltage is output through the voltage output end. Therefore, a worker can judge whether the current infrared light source is stable or not according to whether the detection voltage is stable or not, the condition of frequent manual intervention of calibration or debugging is avoided, and the detection efficiency is greatly improved.

Description

Technical Field

[0001] This utility model relates to the field of self-testing circuit technology, and in particular to a self-testing circuit for infrared optical detection. Background Technology

[0002] Infrared optical sensor chips can detect the intensity of infrared light in the environment. Testing these chips typically requires a light source to provide an infrared light environment and maintain the stability and accuracy of the infrared light source to ensure accurate application by the end user. Because infrared light is not visible, traditional testing equipment lacks self-testing circuitry and therefore cannot determine the operating status of the light source. This often necessitates frequent manual intervention for calibration or adjustment, a cumbersome process that significantly impacts testing efficiency. Utility Model Content

[0003] This utility model specifically provides a self-testing circuit for infrared optical detection.

[0004] The self-testing circuit for infrared optical detection provided by this utility model includes a light source receiving module, an operational amplifier module, and a negative feedback module with a voltage output terminal; the light source receiving module, the operational amplifier module, and the negative feedback module are connected in circuit.

[0005] Preferably, the light source receiving module includes a receiving tube group formed by four sets of infrared receiving tubes connected in parallel, a transistor (Q1), and a first power supply (VS); the gate (G) of the transistor (Q1) is connected to one end of the receiving tube group, the source (S) of the transistor (Q1) is connected to the other end of the receiving tube group and then connected to the negative terminal (VS-) of the first power supply (VS); the drain (D) of the transistor (Q1) is connected to the positive terminal (VS+) of the first power supply (VS).

[0006] Preferably, the transistor (Q1) is a normally closed MOSFET.

[0007] Preferably, the light source receiving module further includes a first resistor (R1) and a second resistor (R2); the first resistor (R1) is connected in series between the source (S) and the negative terminal (VS-) of the first power supply (VS); the second resistor (R2) is connected in series between the drain (D) and the positive terminal (VS+) of the first power supply (VS).

[0008] Preferably, the operational amplifier module includes an operational amplifier chip (U1); the negative feedback module further includes a third resistor (R3) and a first capacitor (C1); after the third resistor (R3) and the first capacitor (C1) are connected in parallel, one end of them is connected to the gate (G), and the other end is connected to the first pin of the operational amplifier chip (U1); the voltage output terminal is connected between the third resistor (R3) and the first pin (1) of the operational amplifier chip (U1); the second pin (2) of the operational amplifier chip (U1) is connected between the source (S) and the first resistor (R1).

[0009] Preferably, the resistance of the third resistor (R3) is 1 MΩ; the capacitance of the first capacitor is 0.5 pF.

[0010] Preferably, the negative feedback module further includes a fourth resistor (R4) and a light-emitting diode (D5); one end of the fourth resistor (R4) is connected in series with the third resistor (R3), and the other end is connected in series with one end of the light-emitting diode (D5); the other end of the light-emitting diode (D5) is grounded.

[0011] Preferably, the self-test circuit for infrared optical detection provided by this utility model further includes a second capacitor (C2), a third capacitor (C3), and a fourth capacitor (C4); one end of the second capacitor (C2) is connected between the second resistor (R2) and the drain (D), and the other end is grounded; one end of the third capacitor (C3) is connected to the third pin of the operational amplifier chip (U1) and grounded, and the other end is connected to the fourth pin of the operational amplifier chip (U1) and connected to the negative terminal (VS-) of the first power supply (VS); one end of the fourth capacitor (C4) is connected between the eighth pin of the operational amplifier chip (U1) and the positive terminal (VS+) of the first power supply (VS), and the other end is grounded.

[0012] Preferably, the capacitance of the second capacitor (C2), the third capacitor (C3), and the fourth capacitor (C4) is 0.1uF.

[0013] Preferably, the operational amplifier chip (U1) further includes a fifth pin, a sixth pin, and a seventh pin.

[0014] The self-testing circuit for infrared optical detection provided by this utility model has a light source receiving module that receives infrared light and converts the invisible infrared light into current. Through the cooperation of the operational amplifier module and the negative feedback module, the current is converted into a voltage signal that varies with the current. Finally, the voltage is output through the voltage output terminal. In this way, the operator only needs to judge whether the current infrared light source is stable by whether the detection voltage is stable, avoiding frequent manual intervention for calibration or debugging, and greatly improving the detection efficiency. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the circuit structure of the self-testing circuit for infrared optical detection provided by this utility model. Detailed Implementation

[0016] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0017] like Figure 1 As shown, the self-test circuit for infrared optical detection provided in this embodiment includes a light source receiving module, an operational amplifier module, and a negative feedback module with a voltage output terminal; the light source receiving module, the operational amplifier module, and the negative feedback module are circuitally connected. Those skilled in the art will understand that the light source receiving module receives infrared light, converting the invisible infrared light into current. Through the cooperation of the operational amplifier module and the negative feedback module, the current is converted into a voltage signal that varies with the current. Finally, the voltage is output through the voltage output terminal. This allows operators to determine the stability of the current infrared light source simply by checking whether the detected voltage is stable, avoiding frequent manual calibration or debugging and greatly improving detection efficiency.

[0018] Furthermore, the light source receiving module includes a receiver group formed by four sets of infrared receiver tubes connected in parallel, a transistor Q1, and a first power supply VS. The gate G of the transistor Q1 is connected to one end of the receiver group, and the source S of the transistor Q1 is connected to the other end of the receiver group and then connected to the negative terminal VS- of the first power supply VS. The drain D of the transistor Q1 is connected to the positive terminal VS+ of the first power supply VS. Those skilled in the art will understand that this circuit uses ±12V power supply, VS+ = 12V, VS- = -12V. After receiving external infrared light, the four infrared receiver tubes D1, D2, D3, and D4 can generate a weak current. The parallel connection of the four receiver tubes can amplify the induced current to four times that of a single tube, thereby improving the sensitivity of the subsequent detection circuit. The induced current passes through the gate G of the N-channel JFET Q1, turning on the transistor Q1.

[0019] Furthermore, the transistor Q1 is a normally closed MOSFET. Those skilled in the art will understand that the use of a normally closed MOSFET in this design results in low input impedance, making it suitable for weak current inputs and thus achieving higher sensitivity.

[0020] Furthermore, the light source receiving module also includes a first resistor R1 and a second resistor R2; the first resistor R1 is connected in series between the source S and the negative terminal VS- of the first power supply VS; the second resistor R2 is connected in series between the drain D and the positive terminal VS+ of the first power supply VS. Those skilled in the art will understand that by adding the first resistor R1 and the second resistor R2 to both the source S and the drain D, a bias is provided for the entire circuit when the transistor Q1 is turned on, preventing excessive operating current.

[0021] Furthermore, the operational amplifier module includes an operational amplifier chip U1; the negative feedback module further includes a third resistor R3 and a first capacitor C1; the third resistor R3 and the first capacitor C1 are connected in parallel, with one end connected to the gate G and the other end connected to the first pin of the operational amplifier chip U1; the voltage output terminal is connected between the third resistor R3 and the first pin 1 of the operational amplifier chip U1; the second pin 2 of the operational amplifier chip U1 is connected between the source S and the first resistor R1. Those skilled in the art will understand that the combination of the third resistor R3 and the first capacitor C1 forms a negative feedback transimpedance amplifier circuit, generating a voltage signal that varies with current at the first pin 1 of the operational amplifier. The operational amplifier chip is existing technology in this field and will not be described in detail here.

[0022] Furthermore, the resistance of the third resistor R3 is 1M ohm; the capacitance of the first capacitor is 0.5pF. Those skilled in the art will understand that the output voltage of the detection circuit is proportional to the product of the third resistor R3 and the induced current. Considering that the induced current of the infrared receiver is only in the microamp level, selecting a high-precision 1M ohm resistor with 0.1% accuracy for the third resistor R3 allows its output range to meet the requirements of -12V to +12V.

[0023] Furthermore, the negative feedback module also includes a fourth resistor R4 and a light-emitting diode D5; one end of the fourth resistor R4 is connected in series with the third resistor R3, and the other end is connected in series with one end of the light-emitting diode D5; the other end of the light-emitting diode D5 is grounded. Those skilled in the art will understand that by adding the fourth resistor R4 as a load resistor and the light-emitting diode D5 as a monitoring function, a rapid functional judgment can be made when there is a detection voltage output greater than 0.7V.

[0024] Furthermore, the self-test circuit for infrared optical detection provided in this embodiment also includes a second capacitor C2, a third capacitor C3, and a fourth capacitor C4; one end of the second capacitor C2 is connected between the second resistor R2 and the drain D, and the other end is grounded; one end of the third capacitor C3 is connected to the third pin of the operational amplifier chip U1 and grounded, and the other end is connected to the fourth pin of the operational amplifier chip U1 and connected to the negative terminal VS- of the first power supply VS; one end of the fourth capacitor C4 is connected between the eighth pin of the operational amplifier chip U1 and the positive terminal VS+ of the first power supply VS, and the other end is grounded. Those skilled in the art will understand that placing the second capacitor C2, the third capacitor C3, and the fourth capacitor C4 at the power supply terminals of each device achieves power supply decoupling and ensures reliable circuit operation.

[0025] Furthermore, the capacitance of the second capacitor C2, the third capacitor C3, and the fourth capacitor C4 is 0.1uF.

[0026] Furthermore, the operational amplifier chip U1 also includes a fifth pin, a sixth pin, and a seventh pin. Those skilled in the art will understand that in subsequent circuit upgrades, this circuit can utilize the fifth, sixth, and seventh pins inside the operational amplifier chip U1 to add another set of operational amplifier circuits, thereby implementing two sets of detection circuits.

[0027] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and not to limit it. Although this utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this utility model.

Claims

1. A self-checking circuit for infrared optical detection, characterized in that, It includes a light source receiving module, an operational amplifier module, and a negative feedback module with a voltage output terminal; the light source receiving module, the operational amplifier module, and the negative feedback module are connected in circuit.

2. The self-checking circuit for infrared optical detection of claim 1, wherein, The light source receiving module includes a receiver tube group formed by four sets of infrared receiver tubes connected in parallel, a transistor (Q1), and a first power supply (VS); the gate (G) of the transistor (Q1) is connected to one end of the receiver tube group, the source (S) of the transistor (Q1) is connected to the other end of the receiver tube group and then connected to the negative terminal (VS-) of the first power supply (VS); the drain (D) of the transistor (Q1) is connected to the positive terminal (VS+) of the first power supply (VS).

3. The self-checking circuit for infrared optical detection of claim 2, wherein, The transistor (Q1) is a normally closed MOSFET.

4. The self-checking circuit for infrared optical detection of claim 3, wherein, The light source receiving module further includes a first resistor (R1) and a second resistor (R2); the first resistor (R1) is connected in series between the source (S) and the negative terminal (VS-) of the first power supply (VS); the second resistor (R2) is connected in series between the drain (D) and the positive terminal (VS+) of the first power supply (VS).

5. The self-checking circuit for infrared optical detection of claim 4, wherein, The operational amplifier module includes an operational amplifier chip (U1); the negative feedback module also includes a third resistor (R3) and a first capacitor (C1); after the third resistor (R3) and the first capacitor (C1) are connected in parallel, one end of them is connected to the gate (G), and the other end is connected to the first pin of the operational amplifier chip (U1); the voltage output terminal is connected between the third resistor (R3) and the first pin (1) of the operational amplifier chip (U1); the second pin (2) of the operational amplifier chip (U1) is connected between the source (S) and the first resistor (R1).

6. The self-checking circuit for infrared optical detection of claim 5, wherein, The resistance of the third resistor (R3) is 1 MΩ; the capacitance of the first capacitor is 0.5 pF.

7. The self-checking circuit for infrared optical detection of claim 6, wherein, The negative feedback module also includes a fourth resistor (R4) and a light-emitting diode (D5); one end of the fourth resistor (R4) is connected in series with the third resistor (R3), and the other end is connected in series with one end of the light-emitting diode (D5); the other end of the light-emitting diode (D5) is grounded.

8. The self-checking circuit for infrared optical detection of claim 7, wherein, It also includes a second capacitor (C2), a third capacitor (C3), and a fourth capacitor (C4); one end of the second capacitor (C2) is connected between the second resistor (R2) and the drain (D), and the other end is grounded; one end of the third capacitor (C3) is connected to the third pin of the operational amplifier chip (U1) and grounded, and the other end is connected to the fourth pin of the operational amplifier chip (U1) and connected to the negative terminal (VS-) of the first power supply (VS); one end of the fourth capacitor (C4) is connected between the eighth pin of the operational amplifier chip (U1) and the positive terminal (VS+) of the first power supply (VS), and the other end is grounded.

9. The self-checking circuit for infrared optical detection of claim 8, wherein, The capacitance of the second capacitor (C2), the third capacitor (C3), and the fourth capacitor (C4) is 0.1uF.

10. The self-checking circuit for infrared optical detection of claim 9, wherein, The operational amplifier chip (U1) also includes a fifth pin, a sixth pin, and a seventh pin.

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