A fiber optic amplifier

Abstract

The invention discloses an optical fiber amplifier, which relates to the technical field of optical fiber sensors. The technical solution thereof includes an outer shell, a card slot board inserted and fixed in the outer shell, and a circuit board fixed on the card slot board. The card slot board is provided with a transmitting tube for emitting an optical signal and a receiving tube for receiving an optical signal. The circuit board is provided with a constant optical power control circuit for controlling the transmitting tube to emit a constant light intensity. The constant optical power control circuit includes a detection module for detecting the light intensity of the transmitting tube and outputting a detection signal, and an execution module coupled to the detection module and receiving the detection signal to control the transmitting tube to emit a constant optical power. The invention has the effect of constant emission optical power and stable sensing data of the optical fiber sensor.

Description

Technical Field

[0001] The present invention relates to the technical field of optical fiber type sensors, and more particularly to an optical fiber amplifier. Background Art

[0002] Fiber optic sensors use optical fiber lines to lead light signals out of the sensor body and detect the object being detected at a place far away from the sensor body. According to the selection of the appropriate fiber optic line sensor head, it can be used in a variety of harsh environments such as narrow, dense, high temperature, high humidity, corrosive, and strong interference. It has the characteristics of precise detection and intelligent control.

[0003] In the prior art, a patent document with application publication number CN103620716A discloses a sensor device comprising a main body and a pair of optical fibers installed on the front surface of the main body, one optical fiber being used for projecting light and the other optical fiber being used for receiving light, and the two optical fibers are respectively inserted into two insertion ports on the front surface of the main body.

[0004] This sensor device is the same as the common ones, which transmits light through the transmitting tube, then receives the signal through the receiving tube, and finally amplifies the signal through the internal control circuit. However, due to the unstable voltage and product production errors, the output of the optical power of the transmitting tube is unstable during use, resulting in unstable sensing data of the optical fiber sensor. Summary of the invention

[0005] In view of the shortcomings of the prior art, the first object of the present invention is to provide a fiber optic amplifier having the effects of constant emitted light power and stable sensing data of the fiber optic sensor.

[0006] To achieve the above-mentioned first purpose, the present invention provides the following technical solutions: an optical fiber amplifier, comprising an outer shell, a slot board inserted and fixed in the outer shell, and a circuit board fixed on the slot board, the slot board is provided with a transmitting tube for emitting an optical signal and a receiving tube for receiving an optical signal, the circuit board is provided with a constant optical power control circuit for controlling the transmitting tube to emit a constant light intensity; the constant optical power control circuit comprises a detection module for detecting the light intensity of the transmitting tube and outputting a detection signal, and an execution module coupled to the detection module and receiving the detection signal to control the transmitting tube to emit a constant optical power.

[0007] By adopting the above technical solution, when the voltage of the optical fiber amplifier decreases due to usage time, the light intensity emitted by the transmitting tube will weaken. At this time, the detection module is used to detect the light intensity of the light emitted by the transmitting tube, and then the detection signal is output. The execution module adjusts and controls the light intensity of the light emitted by the transmitting tube to increase, so that the transmitting tube can work at a constant optical power and the sensing data of the optical fiber sensor can be stabilized.

[0008] In a preferred embodiment, the present invention can be further configured as follows: the detection module includes a feedback tube for changing the resistance value in response to the light intensity of the emitting tube, the feedback tube is a photosensitive diode D1, a first resistor R1 is connected in series between the cathode of the photosensitive diode D1 and the power supply VCC, a second resistor R2 is connected in series between the anode of the photosensitive diode D1 and the ground terminal, and a detection signal is output at the connection point between the anode of the photosensitive diode D1 and the second resistor R2.

[0009] By adopting the above technical solution, when the light intensity of the light emitted by the emitting tube weakens, the resistance of the feedback tube increases, the detection signal is a voltage signal, and the voltage value of the detection signal output decreases. The voltage at this point is the voltage across the second resistor R2, and the light signal of the light intensity is converted into an electrical signal output, which is convenient for subsequent control.

[0010] In a preferred embodiment of the present invention, the configuration may be further as follows: a first capacitor C1 is coupled to a connection point between the first resistor R1 and the cathode of the photodiode D1 , and the other end of the first capacitor C1 is connected to the ground.

[0011] By adopting the above technical solution, the first capacitor C1 has the effect of stabilizing the potential of the connection point between the photodiode D1 and the first resistor R1 through charging and discharging.

[0012] In a preferred embodiment, the present invention can be further configured as follows: a mounting block is fixed on the card slot plate, the mounting block is provided with a receiving hole for placing a receiving tube, a transmitting hole for placing a transmitting tube, and a feedback hole for placing a feedback tube; the feedback hole is connected to the transmitting hole, and the mounting block is provided with a through hole for the pin of the feedback tube to pass through.

[0013] By adopting the above technical solution, the transmitting tube and the feedback tube are both installed on the mounting block, and the structure in which the transmitting hole and the feedback hole are connected facilitates the feedback tube to collect the optical signal.

[0014] In a preferred embodiment, the present invention can be further configured as follows: the feedback hole includes a large annular hole and a small annular hole that are connected, the small annular hole is connected to the emission hole, the aperture of the large annular hole is larger than the aperture of the small annular hole, and the large annular hole is connected to the side of the small annular hole away from the emission hole.

[0015] By adopting the above technical solution, the feedback tube is first inserted into the large annular hole far away from the emission hole, and then inserted into the small annular hole with a smaller aperture, which has the effect of facilitating the insertion of the feedback tube.

[0016] The present invention can be further configured as follows in a preferred embodiment: the execution module includes a dual-channel analog switch and an operational amplifier; the dual-channel analog switch is a TC7WB66 chip, and the model of the operational amplifier is LM358; the VCC terminal of the TC7WB66 chip is connected to the power supply VCC, the GND terminal of the TC7WB66 chip is connected to the ground terminal, the OE1 terminal and the OE2 terminal of the TC7WB66 chip are coupled to and receive the pulse transmission signal TX, the A1 terminal of the TC7WB66 chip is coupled to the connection point between the first resistor R1 and the cathode of the photosensitive diode D1 and receives the detection signal, the B1 pin of the TC7WB66 chip is coupled to the inverting input terminal of the operational amplifier, and a second capacitor C is connected in series between the B1 pin of the TC7WB66 chip and the ground terminal. 2. A fourth capacitor C4 is connected in series between the A2 terminal of the TC7WB66 chip and the ground terminal, a third resistor R3 is connected in series between the A2 terminal of the TC7WB66 chip and the output terminal of the operational amplifier, the non-inverting input terminal of the operational amplifier receives a stable DC voltage DAC, a third capacitor C3 is connected in series between the output terminal and the inverting input terminal of the operational amplifier, a base of a transistor Q1 is coupled to the B2 terminal of the TC7WB66 chip, a sixth resistor R6 is coupled to the emitter of the transistor Q1 and the ground terminal, a fifth resistor R5 is connected in series between the base and the emitter of the transistor Q1, the emitting tube is a light-emitting diode D2, the collector of the transistor Q1 is coupled to the cathode of the light-emitting diode D2, and a fourth resistor R4 is connected in series between the anode of the light-emitting diode D2 and the power supply VCC.

[0017] By adopting the above technical solution, the pulse transmission signal TX gives a high-level pulse. During the pulse duration, the dual-way analog switch is turned on, and the A1 terminal of the TC7WB66 chip receives a voltage signal, which is the voltage drop of the second resistor R2; when the light intensity of the light emitted by the transmitting tube decreases, the resistance of the photosensitive diode D1 increases, and the voltage received by the A1 terminal of the TC7WB66 chip decreases. The voltage value output by the B1 terminal of the TC7WB66 chip is the voltage drop V2 generated by the photocurrent on the second resistor R2. The stable DC voltage DAC is the stable DC voltage V1 provided by the microcontroller DAC. When V2 is less than V1, the output voltage of the operational amplifier will increase, and through the third resistor R3 and the fourth capacitor C4, through the second switch channel of the dual-way analog switch that is turned on, that is, the B2 terminal of the TC7WB66 chip, it is loaded to the base of the transistor Q1, so that the conduction degree of Q1 increases, the current on the transmitting tube is increased, and the light intensity of the transmitting tube is enhanced. As the light intensity of the photodiode D1 increases, V2 becomes larger until V2=V1. The output voltage of the operational amplifier no longer changes and becomes stable. In this way, the current passing through the transmitting tube also reaches a stable value, and the light intensity emitted by the transmitting tube is directly proportional to V1.

[0018] In a preferred embodiment of the present invention, a fifth capacitor C5 is connected in series between the anode of the light emitting diode D2 and the ground terminal.

[0019] By adopting the above technical solution, the fifth capacitor C5 has the effect of stabilizing the potential of the connection point between the transmitting tube and the fourth resistor R4 through charging and discharging.

[0020] In summary, the present invention detects the light intensity of the transmitting tube, and when the light intensity weakens, increases the current passing through the transmitting tube through the execution module to enhance the light intensity of the transmitting tube. Through the control of the operational amplifier and the dual-channel analog switch, V2 is equal to V1, so that the light intensity of the transmitting tube is in direct proportion to V1, and the transmitting tube maintains a fixed optical power output throughout its life cycle, thereby enhancing the stability of the sensing data of the optical fiber sensor. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a partial structural schematic diagram of the present invention;

[0022] Figure 2 It is a partial structural explosion schematic diagram of the present invention;

[0023] Figure 3 It is a schematic cross-sectional view of a local structure of the present invention;

[0024] Figure 4 It is a circuit diagram of the constant light power control circuit in the present invention.

[0025] Figure numerals: 1. outer shell; 2. card slot board; 3. circuit board; 4. mounting block; 5. receiving hole; 6. transmitting hole; 7. feedback hole; 8. receiving tube; 9. transmitting tube; 10. feedback tube; 11. large annular hole; 12. small annular hole; 13. via; 14. detection module; 15. execution module; 16. dual-channel analog switch; 17. operational amplifier. DETAILED DESCRIPTION

[0026] The present invention will be further described with reference to the accompanying drawings.

[0027] Reference Figure 1 , Figure 2 , is a fiber optic amplifier disclosed in this embodiment, comprising an outer shell 1, a slot board 2 inserted into and fixed in the outer shell 1, and a circuit board 3 fixed on the slot board 2.

[0028] Reference Figure 2 , Figure 3 A mounting block 4 is fixed on the card slot plate 2, and a receiving hole 5, a transmitting hole 6, and a feedback hole 7 are formed on the mounting block 4. A receiving tube 8 for receiving optical signals is installed in the receiving hole 5, a transmitting tube 9 for sending optical signals is installed in the transmitting hole 6, and a feedback tube 10 is installed in the feedback hole 7.

[0029] Reference Figure 2 , Figure 3 The feedback hole 7 is connected with the emission hole 6, and a through hole 13 is opened on the mounting block 4 for the pin of the feedback tube 10 to pass through. The feedback hole 7 includes a large annular hole 11 and a small annular hole 12 that are connected. The small annular hole 12 is connected with the emission hole 6. The aperture of the large annular hole 11 is larger than the aperture of the small annular hole 12. The large annular hole 11 is connected to the side of the small annular hole 12 away from the emission hole 6. The feedback tube 10 is first inserted into the large annular hole 11 far away from the emission hole 6, and then inserted into the small annular hole 12 with a smaller aperture, which has the effect of facilitating the insertion of the feedback tube 10.

[0030] Reference Figure 3 , Figure 4 The circuit board 3 is provided with a constant light power control circuit for controlling the transmitting tube 9 to emit a constant light intensity. The constant light power control circuit includes a detection module 14 for detecting the light intensity of the transmitting tube 9 and outputting a detection signal, and an execution module 15 coupled to the detection module 14 and receiving the detection signal to control the transmitting tube 9 to emit a constant light power.

[0031] Reference Figure 3 , Figure 4 , the detection module 14 includes a feedback tube 10 for changing the resistance value in response to the light intensity of the transmitting tube 9. The feedback tube 10 adopts a photosensitive diode D1. A first resistor R1 is connected in series between the cathode of the photosensitive diode D1 and the power supply VCC. The connection point between the first resistor R1 and the cathode of the photosensitive diode D1 is coupled with a first capacitor C1, and the other end of the first capacitor C1 is connected to the ground. A second resistor R2 is connected in series between the anode of the photosensitive diode D1 and the ground terminal, and a detection signal is output at the connection point between the anode of the photosensitive diode D1 and the second resistor R2. When the light intensity of the light emitted by the transmitting tube 9 decreases, the resistance of the feedback tube 10 increases, the detection signal is a voltage signal, and the voltage value of the detection signal output decreases. The voltage at this point is the voltage across the second resistor R2, and the light signal of the light intensity is converted into an electrical signal output, which is convenient for later control.

[0032] Reference Figure 3 , Figure 4, the execution module 15 includes a dual-channel analog switch 16 and an operational amplifier 17; the dual-channel analog switch 16 is a TC7WB66 chip, and the model of the operational amplifier 17 is LM358; the VCC terminal of the TC7WB66 chip is connected to the power supply VCC, the GND terminal of the TC7WB66 chip is connected to the ground terminal, the OE1 terminal and the OE2 terminal of the TC7WB66 chip are coupled and receive the pulse transmission signal TX, the A1 terminal of the TC7WB66 chip is coupled to the connection point between the first resistor R1 and the cathode of the photosensitive diode D1 and receives the detection signal, the B1 pin of the TC7WB66 chip is coupled to the inverting input terminal of the operational amplifier 17, the second capacitor C2 is connected in series between the B1 pin of the TC7WB66 chip and the ground terminal, the A2 terminal of the TC7WB66 chip and the ground terminal are connected in series with a fourth capacitor C4, and the TC7WB66 chip is connected to the ground terminal. A third resistor R3 is connected in series between the A2 end of the WB66 chip and the output end of the operational amplifier 17. The non-inverting input end of the operational amplifier 17 receives the stable DC voltage V1 provided by the microcontroller DAC. A third capacitor C3 is connected in series between the output end and the inverting input end of the operational amplifier 17. The B2 end of the TC7WB66 chip is coupled to the base of the transistor Q1. The transistor Q1 is an NPN transistor. The emitter of the transistor Q1 is coupled to the ground end with a sixth resistor R6. A fifth resistor R5 is connected in series between the base and the emitter of the transistor Q1. The transmitting tube 9 is a light-emitting diode D2. The collector of the transistor Q1 is coupled to the cathode of the light-emitting diode D2. A fourth resistor R4 is connected in series between the anode of the light-emitting diode D2 and the power supply VCC. A fifth capacitor C5 is connected in series between the anode of the light-emitting diode D2 and the ground end. The pulse transmission signal TX gives a high-level pulse. During the pulse duration, the dual-way analog switch 16 is turned on, and the A1 terminal of the TC7WB66 chip receives a voltage signal, which is the voltage drop of the second resistor R2. When the light intensity of the light emitted by the transmitting tube 9 decreases, the resistance of the photodiode D1 increases, and the voltage received by the A1 terminal of the TC7WB66 chip decreases. The voltage value output by the B1 terminal of the TC7WB66 chip is the voltage drop V2 generated by the photocurrent on the second resistor R2. When V2 is less than V1, the output voltage of the operational amplifier 17 will increase, and through the third resistor R3 and the fourth capacitor C4, through the second switch channel of the turned-on dual-way analog switch 16, that is, the B2 terminal of the TC7WB66 chip, it is loaded to the base of the transistor Q1, so that the conduction degree of Q1 increases, the current on the transmitting tube 9 is increased, and the light intensity of the transmitting tube 9 is enhanced. As the light intensity of the photodiode D1 increases, V2 increases until V2=V1. The output voltage of the operational amplifier 17 stops changing and becomes stable. In this way, the current passing through the transmitting tube 9 also reaches a stable value. The light intensity of the transmitting tube 9 is directly proportional to V1.

[0033] The specific effects are as follows:

[0034] When the voltage of the optical fiber amplifier decreases due to the use time, the light intensity emitted by the transmitting tube 9 will weaken, the resistance of the feedback tube 10 will increase, V2 will decrease, and the current passing through the transmitting tube 9 in the execution module 15 will increase, thereby enhancing the light intensity of the transmitting tube 9. Through the control of the operational amplifier 17 and the dual-channel analog switch 16, V2 is equal to V1, so that the light intensity of the transmitting tube 9 is in direct proportion to V1, so that the transmitting tube 9 maintains a fixed optical power output throughout its life cycle, thereby enhancing the stability of the sensing data of the optical fiber sensor.

[0035] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the design concept of the present invention should be included in the protection scope of the present invention.

Claims

1. An optical fiber amplifier, comprising an outer shell (1), a slot board (2) inserted and fixed in the outer shell (1), and a circuit board (3) fixed on the slot board (2), wherein the slot board (2) is provided with a transmitting tube (9) for emitting an optical signal and a receiving tube (8) for receiving an optical signal, wherein: The circuit board (3) is provided with a constant light power control circuit for controlling the transmitting tube (9) to emit a constant light intensity; the constant light power control circuit comprises a detection module (14) for detecting the light intensity of the transmitting tube (9) and outputting a detection signal, and an execution module (15) coupled to the detection module (14) and receiving the detection signal to control the transmitting tube (9) to emit a constant light power; the detection module (14) comprises a feedback tube (10) for changing a resistance value in response to the light intensity of the transmitting tube (9), the feedback tube (10) adopts a photosensitive diode D1, and a cathode of the photosensitive diode D1 is connected in series with a power supply VCC. A first resistor R1, a second resistor R2 is connected in series between the positive electrode of the photosensitive diode D1 and the grounding terminal, and a connection point between the positive electrode of the photosensitive diode D1 and the second resistor R2 outputs a detection signal; a first capacitor C1 is coupled to a connection point between the first resistor R1 and the negative electrode of the photosensitive diode D1, and the other end of the first capacitor C1 is connected to the grounding terminal; the execution module (15) comprises a dual-channel analog switch (16) and an operational amplifier (17); the dual-channel analog switch (16) is a TC7WB66 chip, and the model of the operational amplifier (17) is LM358; the VCC terminal of the TC7WB66 chip is connected to the power supply VCC, and the TC7 The GND terminal of the WB66 chip is connected to the ground terminal, the OE1 terminal and the OE2 terminal of the TC7WB66 chip are coupled to receive the pulse transmission signal TX, the A1 terminal of the TC7WB66 chip is coupled to the connection point between the first resistor R1 and the cathode of the photosensitive diode D1 and receives the detection signal, the B1 pin of the TC7WB66 chip is coupled to the inverting input terminal of the operational amplifier (17), a second capacitor C2 is connected in series between the B1 pin of the TC7WB66 chip and the ground terminal, a fourth capacitor C4 is connected in series between the A2 terminal of the TC7WB66 chip and the ground terminal, and the A2 terminal of the TC7WB66 chip is connected to the input terminal of the operational amplifier (17). A third resistor R3 is connected in series between the output terminals, a non-inverting input terminal of the operational amplifier (17) receives a stable DC voltage DAC, a third capacitor C3 is connected in series between the output terminal and the inverting input terminal of the operational amplifier (17), a B2 terminal of the TC7WB66 chip is coupled to the base of the transistor Q1, a sixth resistor R6 is coupled to the emitter of the transistor Q1 and the ground terminal, a fifth resistor R5 is connected in series between the base and the emitter of the transistor Q1, the transmitting tube (9) is a light emitting diode D2, a collector of the transistor Q1 is coupled to the cathode of the light emitting diode D2, and a fourth resistor R4 is connected in series between the anode of the light emitting diode D2 and the power supply VCC.

2. The optical fiber amplifier according to claim 1, characterized in that: A mounting block (4) is fixed on the card slot plate (2), and the mounting block (4) is provided with a receiving hole (5) for placing a receiving tube (8), a transmitting hole (6) for placing a transmitting tube (9), and a feedback hole (7) for placing a feedback tube (10); the feedback hole (7) is connected to the transmitting hole (6), and the mounting block (4) is provided with a through hole (13) for a pin of the feedback tube (10) to pass through.

3. The optical fiber amplifier according to claim 2, characterized in that: The feedback hole (7) comprises a large annular hole (11) and a small annular hole (12) which are connected to each other. The small annular hole (12) is connected to the emission hole (6). The aperture of the large annular hole (11) is larger than the aperture of the small annular hole (12). The large annular hole (11) is connected to the side of the small annular hole (12) away from the emission hole (6).

4. The optical fiber amplifier according to claim 1, characterized in that: A fifth capacitor C5 is connected in series between the anode of the light emitting diode D2 and the ground terminal.

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