Photoelectric sensing circuit and photoelectric sensor

Abstract

The present invention discloses a photoelectric sensing circuit and a photoelectric sensor. The photoelectric sensing circuit includes a driving module, a feedback module, a light receiving module, a control module and a signal output module. The driving module drives a light emitting diode to emit a light signal; the feedback module converts the light signal into a first electrical signal and outputs it to the driving module; the light receiving module converts the light signal into a second electrical signal, and outputs a third electrical signal after amplifying the second electrical signal; the control module controls the driving module to drive the light emitting diode according to a preset frequency, controls the feedback module to adjust the brightness of the light emitting diode, and receives the third electrical signal and controls the signal output module to output a signal according to the third electrical signal. In the technical solution, the modules cooperate with each other, so that the photoelectric sensing circuit can maintain stable light signal transmission and receiving capabilities under different environments.

Description

Technical Field

[0001] The present invention relates to the field of photoelectric sensing technology, and in particular to a photoelectric sensing circuit and a photoelectric sensor. Background Art

[0002] At present, light receiving systems have been widely used in many fields, such as automated detection, optical communication, sensors, and security monitoring. A light receiving system composed of a light emitting diode and a photodiode is a common configuration, which transmits light signals through a light emitting diode and receives reflected or transmitted light signals through a photodiode to achieve information transmission or monitoring. However, in practical applications, due to factors such as ambient light interference, temperature changes, and device aging, the stability of the light receiving system is often difficult to guarantee, resulting in signal fluctuations and affecting the accuracy and reliability of the system.

[0003] Existing solutions mostly rely on adjusting the intensity of the light source or adding filtering circuits to reduce ambient light interference. However, these methods have improved the system's anti-interference ability to a certain extent, but in actual operation, there are still problems such as poor stability, slow response speed, and high cost. Especially in complex environments, the emission intensity of the light source is difficult to maintain constant, resulting in frequent fluctuations in the signal received by the photodiode, thereby reducing the detection accuracy of the system. Summary of the invention

[0004] The embodiments of the present invention provide a photoelectric sensing circuit and a photoelectric sensor to solve the above technical problems.

[0005] A first aspect of an embodiment of the present invention provides a photoelectric sensor circuit, including:

[0006] A driving module, connected to the light emitting diode, and used to drive the light emitting diode to emit a light signal;

[0007] a feedback module, connected to the driving module, configured to convert the optical signal into a first electrical signal and output the first electrical signal to the driving module;

[0008] an optical receiving module, used for converting the optical signal into a second electrical signal, and amplifying the second electrical signal to output a third electrical signal;

[0009] A control module and a signal output module, wherein the control module is respectively connected to the driving module, the feedback module, the light receiving module and the signal output module, and is used to control the driving module to drive the light-emitting diode according to a preset frequency, control the feedback module to adjust the brightness of the light-emitting diode, and receive the third electrical signal and control the signal output module to output a signal according to the third electrical signal.

[0010] Optionally, the driving module includes a first switch module, a filter module, a first operational amplifier module, a second switch module and a transistor, and the feedback module includes a third switch module, a fourth switch module and a first photodiode;

[0011] One end of the first switch module receives the power supply voltage, the other end of the first switch module is connected to the input end of the filter module, the output end of the filter module is connected to the first input end of the first operational amplifier module, the second input end of the first operational amplifier module is connected to one end of the third switch module, the other end of the third switch module is connected to one end of the fourth switch module, the other end of the fourth switch module is connected to the anode of the first photodiode, the output end of the first operational amplifier module is connected to one end of the second switch module, the other end of the second switch module is connected to the base of the transistor, and the transistor and the light-emitting diode form a first current branch;

[0012] The control module is respectively connected to the control end of the first switch module, the control end of the second switch module, the control end of the third switch module and the control end of the fourth switch module. The control module controls the first switch module and the second switch module to make the light emitting diode emit light at a preset frequency, and adjusts the brightness of the light emitting diode by controlling the third switch module and the fourth switch module.

[0013] Optionally, the filtering module includes a fourteenth resistor, a fifteenth resistor, a sixteenth resistor, a seventeenth resistor, a twenty-third capacitor, a twenty-fourth capacitor, a twenty-fifth capacitor and a twenty-sixth capacitor;

[0014] One end of the fourteenth resistor is the input end of the filtering module, the other end of the fourteenth resistor is respectively connected to one end of the fifteenth resistor and one end of the twenty-fourth capacitor, the other end of the fifteenth resistor is respectively connected to one end of the sixteenth resistor and one end of the twenty-sixth capacitor, the other end of the sixteenth resistor is respectively connected to one end of the seventeenth resistor and one end of the twenty-fifth capacitor, the other end of the seventeenth resistor and one end of the twenty-third capacitor are commonly connected as the output end of the filtering module, and the other ends of the twenty-third capacitor, the twenty-fourth capacitor, the twenty-fifth capacitor and the twenty-sixth capacitor are commonly connected to ground.

[0015] Optionally, the light receiving module includes a second photodiode, a first amplifying module and a second amplifying module;

[0016] The output end of the second photodiode is connected to the input end of the first amplifying module, and the output end of the first amplifying module is connected to the input end of the second amplifying module;

[0017] The second photodiode converts the optical signal into a second electrical signal, the first amplification module performs a first-stage amplification on the second electrical signal, and the second amplification module performs a second-stage amplification on the first-stage amplified second electrical signal and outputs a third electrical signal.

[0018] Optionally, the first amplification module includes a second operational amplifier, a fifth resistor, a sixth resistor, a ninth resistor, an eleventh resistor, a twenty-third resistor, a twenty-fourth resistor, a twenty-fifth resistor, an eighth capacitor, a twelfth capacitor, a fifteenth capacitor, a twenty-second capacitor and a twenty-eighth capacitor;

[0019] One end of the ninth resistor is connected to the first voltage, the other end of the ninth resistor is respectively connected to one end of the eleventh resistor and one end of the twenty-second capacitor, the other end of the twenty-second capacitor is grounded, the other end of the eleventh resistor and one end of the fifteenth capacitor are commonly connected to the input end of the first amplification module, the other end of the fifteenth capacitor is respectively connected to one end of the fifth resistor, one end of the eighth capacitor and the inverting input end of the second operational amplifier, the other end of the fifth resistor is connected to one end of the sixth resistor, the power supply end of the second operational amplifier is commonly connected to one end of the twelfth capacitor and receives the first voltage, the other end of the twelfth capacitor is grounded, the non-inverting input end of the second operational amplifier is respectively connected to one end of the twenty-eighth capacitor, one end of the twenty-third resistor and one end of the twenty-fourth resistor, the other end of the twenty-fourth resistor is connected to one end of the twenty-fifth resistor, the other end of the twenty-fifth resistor receives the first voltage, the other end of the twenty-eighth capacitor and the other end of the twenty-third resistor are commonly connected to the ground, and the output end of the second operational amplifier, the other end of the sixth resistor and the other end of the eighth capacitor are commonly connected to the output end of the first amplification module.

[0020] Optionally, the second amplification module includes a third operational amplifier, a fifth switch module, a sixth switch module, a first resistor, a third resistor, an eighth resistor, a thirteenth resistor, a first capacitor, a third capacitor, a sixth capacitor, a thirteenth capacitor, a seventeenth capacitor and a twenty-ninth capacitor;

[0021] One end of the seventeenth capacitor is connected to the output end of the first amplification module, the other end of the seventeenth capacitor is connected to one end of the thirteenth resistor, the other end of the thirteenth resistor is respectively connected to one end of the first resistor, one end of the third capacitor, one end of the third resistor, one end of the sixth capacitor, one end of the eighth resistor and the inverting input end of the third operational amplifier, the non-inverting input end of the third operational amplifier is respectively connected to one end of the twenty-ninth capacitor and one end of the twenty-fifth resistor, the other end of the twenty-ninth capacitor is grounded, the output end of the third operational amplifier is respectively connected to one end of the fifth switch module, one end of the sixth switch module, the other end of the sixth capacitor and the other end of the eighth resistor, the power supply end of the third operational amplifier and one end of the thirteenth capacitor are connected in common to receive the first voltage, the other end of the thirteenth capacitor is grounded, the other end of the fifth switch module is connected to the other end of the first resistor, the power supply end of the fifth switch module and the first end of the first capacitor are connected in common to receive the first voltage, the other end of the first capacitor is grounded, and the other end of the sixth switch is respectively connected to the other end of the third capacitor and the other end of the third resistor.

[0022] Optionally, the optical receiving module further includes a seventh switch module, an eighteenth capacitor, a thirtieth capacitor, a thirty-first capacitor, a nineteenth resistor, a twenty-second resistor, a twenty-seventh resistor, a third diode and a fifth diode;

[0023] One end of the eighteenth capacitor is connected to the output end of the third operational amplifier, the other end of the eighteenth capacitor, one end of the seventh switch module, one end of the nineteenth resistor, the anode of the third diode and the cathode of the fifth diode are connected together as the output end of the optical receiving module, the other end of the seventh switch module is respectively connected to one end of the twenty-seventh resistor and one end of the thirty-first capacitor, the other end of the twenty-seventh resistor receives the second voltage, the other end of the nineteenth resistor is grounded, the other end of the thirty-first capacitor is grounded, the control end of the seventh switch module is connected to one end of the twenty-second resistor, the other end of the twenty-second resistor is grounded, the power supply end of the seventh switch module and one end of the thirtieth capacitor are connected together to receive the first voltage, the other end of the thirtieth capacitor is grounded, the cathode of the third diode receives the second voltage, and the anode of the fifth diode is grounded.

[0024] Optionally, the signal output module includes a thirty-ninth resistor, a forty-second resistor, a forty-third resistor, a forty-fifth resistor, a sixth transistor, a seventh diode and an eighth voltage regulator;

[0025] One end of the thirty-ninth resistor is the input end of the signal output module, the other end of the thirty-ninth resistor is respectively connected to one end of the forty-second resistor and the base of the sixth transistor, the other end of the forty-second resistor is grounded, the collector of the sixth transistor is respectively connected to the cathode of the seventh diode and the cathode of the eighth voltage-regulating diode, the anode of the seventh diode is the output end of the signal output module, the anode of the eighth voltage-regulating diode is grounded, the emitter of the sixth transistor is connected to one end of the forty-third resistor, the other end of the forty-third resistor is connected to one end of the forty-fifth resistor, and the other end of the forty-fifth resistor is grounded.

[0026] Optionally, the signal output module further includes a thirty-first resistor, a forty-first resistor and a seventh transistor;

[0027] One end of the forty-first resistor is connected to the emitter of the sixth transistor, the other end of the forty-first resistor is connected to the base of the seventh transistor, the collector of the seventh transistor and one end of the thirty-first resistor are connected together as the overcurrent detection end of the signal output module, the other end of the thirty-first resistor receives the third voltage, and the emitter of the seventh transistor is grounded.

[0028] A second aspect of an embodiment of the present invention provides a photoelectric sensor, comprising: the photoelectric sensor circuit and a light emitting diode described in the first aspect.

[0029] The technical effect of the embodiment of the present invention is: a closed-loop control system is formed through the precise light source control of the driving module, the real-time light intensity adjustment of the feedback module, the efficient signal amplification processing of the light receiving module, the intelligent management of the control module and the signal transmission of the signal output module. The modules cooperate with each other, so that the photoelectric sensor circuit can maintain stable optical signal transmission and reception capabilities in different environments. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments of the present invention will be briefly introduced below. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative labor.

[0031] Figure 1 is a schematic structural diagram of a photoelectric sensor circuit provided in Embodiment 1 of the present invention;

[0032] Figure 2 It is a structural schematic diagram of a driving module and a feedback module in a photoelectric sensor circuit provided in Embodiment 1 of the present invention;

[0033] Figure 3This is a circuit diagram of the connection between a driving module and a feedback module in a photoelectric sensor circuit provided in Embodiment 1 of the present invention;

[0034] Figure 4 is a structural schematic diagram of a light receiving module in a photoelectric sensor circuit provided in Embodiment 1 of the present invention;

[0035] Figure 5 is a circuit diagram of a light receiving module in a photoelectric sensor circuit provided in Embodiment 1 of the present invention;

[0036] Figure 6 is a circuit diagram of a control module in a photoelectric sensor circuit provided in Embodiment 1 of the present invention;

[0037] Figure 7 is a circuit diagram of a signal output module in a photoelectric sensor circuit provided in Embodiment 1 of the present invention;

[0038] Figure 8 This is a circuit diagram of the first part of a power module in a photoelectric sensor circuit provided in Embodiment 1 of the present invention;

[0039] Fig. 9 is a circuit diagram of the second part of a power module in a photoelectric sensor circuit provided in the first embodiment of the present invention;

[0040] Fig.10 is a circuit diagram of the third part of a power module in a photoelectric sensor circuit provided in the first embodiment of the present invention;

[0041] In the figure: 101, driving module; 102, feedback module; 103, light receiving module; 104, control module; 105, signal output module; 111, first switch module; 112, filter module; 113, first operation module; 114, second switch module; 115, transistor; 121, fourth switch module; 122, third switch module; 123, first photodiode; 131, second photodiode; 132, first amplification module; 133, second amplification module; 20, light emitting diode. DETAILED DESCRIPTION

[0042] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0043] It should be understood that the present invention can be implemented in different forms and should not be construed as being limited to the embodiments set forth herein. On the contrary, providing these embodiments will make the disclosure thorough and complete and fully convey the scope of the present invention to those skilled in the art. In the accompanying drawings, the sizes and relative sizes of layers and regions may be exaggerated for clarity. The same reference numerals throughout represent the same elements.

[0044] It should be understood that when an element or layer is referred to as being "on, adjacent to, connected to or coupled to other elements or layers, it may be directly on, adjacent to, connected to or coupled to other elements or layers, or there may be intervening elements or layers. In contrast, when an element is referred to as being "directly on, directly adjacent to, directly connected to or directly coupled to other elements or layers, there may be no intervening elements or layers. It should be understood that, although the terms first, second, third, etc. may be used to describe various elements, components, regions, layers and / or parts, these elements, components, regions, layers and / or parts should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer or part from another element, component, region, layer or part. Therefore, without departing from the teachings of the present invention, the first element, component, region, layer or part discussed below may be represented as a second element, component, region, layer or part.

[0045] The purpose of the terms used herein is only to describe specific embodiments and is not intended to be limiting of the present invention. When used herein, the singular forms "one", "an" and "said / the" are also intended to include plural forms, unless the context clearly indicates otherwise. It should also be understood that the terms "consisting of" and / or "comprising", when used in this specification, determine the presence of the features, integers, steps, operations, elements and / or parts, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, parts and / or groups. When used herein, the term "and / or" includes any and all combinations of the relevant listed items.

[0046] In order to fully understand the present invention, detailed structures and steps will be presented in the following description to illustrate the technical solutions proposed by the present invention. The preferred embodiments of the present invention are described in detail below, but in addition to these detailed descriptions, the present invention may also have other implementations.

[0047] Embodiment 1

[0048] This embodiment 1 provides a photoelectric sensor circuit, such as Figure 1 As shown, including:

[0049] A driving module 101, which is connected to the light emitting diode 20 and is used to drive the light emitting diode 20 to emit a light signal;

[0050] A feedback module 102, connected to the driving module 101, for converting the optical signal into a first electrical signal and outputting the first electrical signal to the driving module 101;

[0051] The optical receiving module 103 is used to convert the optical signal into a second electrical signal, and amplify the second electrical signal to output a third electrical signal;

[0052] The control module 104 and the signal output module 105, the control module 104 is respectively connected to the driving module 101, the feedback module 102, the light receiving module 103 and the signal output module 105, and is used to control the driving module 101 to drive the light-emitting diode 20 according to a preset frequency, control the feedback module 102 to adjust the brightness of the light-emitting diode 20, and receive a third electrical signal and control the signal output module 105 to output a signal according to the third electrical signal.

[0053] Among them, the driving module 101 drives the light emitting diode 20 to emit a light signal. Through the PWM signal output by the control module 104, the driving module 101 adjusts the brightness and light-emitting frequency of the light emitting diode 20 so that it emits light stably within a set period. The driving module 101 receives the control signal from the control module 104 and outputs the corresponding driving current to control the light-emitting state of the light emitting diode 20. The feedback module 102 is used to monitor the light intensity of the light source in real time, and convert the detected light signal into a first electrical signal, which is fed back to the driving module 101 for adjustment. The feedback module 102 receives the light signal emitted by the light emitting diode 20 through a photodiode, and converts the light signal into an electrical signal. The generated electrical signal is provided as a feedback signal to the driving module 101, so that it adjusts the output light intensity of the light emitting diode 20 to maintain a constant light-emitting effect. The light receiving module 103 is used to receive the light signal emitted by the light emitting diode 20, convert it into a second electrical signal, and amplify the signal and output it as a third electrical signal. The light receiving module 103 uses a photodiode to convert the received light signal into a weak electrical signal (second electrical signal). Since the signal is usually weak, the light receiving module 103 includes a two-stage amplifier circuit, which amplifies the signal respectively to obtain an amplified third electrical signal, which is convenient for subsequent analysis and processing. The control module 104 is the core of the entire system, responsible for coordinating the work of each module, controlling the light emitting process of the light source and the processing of the received signal. The control module 104 generates a PWM signal to control the driving module 101 to drive the light emitting diode 20 to emit light according to a preset frequency, and at the same time receives the first electrical signal generated by the feedback module 102 to adjust the brightness of the light source. The control module 104 also receives the third electrical signal output by the light receiving module 103, analyzes and processes it, and controls the signal output module 105 to output the signal according to the analysis result. The signal output module 105 is responsible for transmitting the processed signal to the external device through the set output mode, and also has an overcurrent protection function. When the control module 104 receives the third electrical signal output by the light receiving module 103, the signal output module 105 outputs according to the control signal.

[0054] The technical effect of the technical solution provided in the first embodiment is that the photoelectric sensing circuit forms a closed-loop control system through the precise light source control of the driving module, the real-time light intensity regulation of the feedback module, the efficient signal amplification processing of the light receiving module, the intelligent management of the control module and the signal transmission of the signal output module. The modules cooperate with each other, so that the system can maintain stable optical signal transmission and reception capabilities in different environments. Through closed-loop feedback and signal amplification processing, the system realizes high-precision detection of optical signals, which is widely applicable to application scenarios such as optical communication and automated detection, and has high efficiency, stability and reliability.

[0055] As an implementation method, Figure 2As shown, the driving module 101 includes a first switch module 111, a filter module 112, a first operational amplifier module 113, a second switch module 114 and a transistor 115, and the feedback module 102 includes a third switch module 122, a fourth switch module 121 and a first photodiode 123; one end of the first switch module 111 receives a power supply voltage VCC, the other end of the first switch module 111 is connected to an input end of the filter module 112, the output end of the filter module 112 is connected to a first input end of the first operational amplifier module 113, the second input end of the first operational amplifier module 113 is connected to one end of the third switch module 122, the other end of the third switch module 122 is connected to one end of the fourth switch module 121, and the fourth switch module 121 The other end of the first operational amplifier module 113 is connected to the anode of the first photodiode 123, the output end of the first operational amplifier module 113 is connected to one end of the second switch module 114, the other end of the second switch module 114 is connected to the base of the transistor 115, and the transistor 115 and the light-emitting diode 20 form a first current branch; the control module 104 is respectively connected to the control end of the first switch module 111, the control end of the second switch module 114, the control end of the third switch module 122 and the control end of the fourth switch module 121, and the control module 104 controls the first switch module 111 and the second switch module 114 to make the light-emitting diode 20 emit light according to a preset frequency, and adjusts the brightness of the light-emitting diode 20 by controlling the third switch module 122 and the fourth switch module 121.

[0056] Among them, the first switch module 111 receives the power supply voltage and controls the power supply state of the power supply to the subsequent circuit. Under the control of the control module 104, the first switch module 111 can open or close the power supply path, thereby controlling whether the light-emitting diode 20 obtains power supply. The filter module 112 filters the power supply signal transmitted from the first switch module 111 and provides a stable DC voltage to the subsequent circuit. The filter module 112 receives the voltage signal transmitted from the first switch module 111, removes the high-frequency noise and pulsation components in the voltage signal through filter elements such as capacitors and resistors, and transmits the filtered stable DC voltage to the first input end of the first operational amplifier module 113. The first operational amplifier module 113 compares the difference between the filtered stable voltage signal and the feedback signal, and outputs an adjustment signal. The first operational amplifier module 113 has two input ends: the first input end receives the stable voltage from the filter module 112, and the second input end receives the light intensity signal from the feedback module 102. The first operational amplifier module 113 compares the two input signals and outputs an adjustment signal according to the difference, which is used to control the working state of the second switch module 114 and the transistor 115. The second switch module 114 receives the output signal of the first operational amplifier module 113, and the control module 104 controls the switching frequency of the second switch module 114 by outputting a PWM control signal to the second switch module 114, thereby controlling the conduction state of the transistor 115, and indirectly adjusting the driving current of the light-emitting diode 20. Under the action of the control module 104, the second switch module 114 controls the base current of the transistor 115 according to the signal output by the operational amplifier, and adjusts the conduction degree of the transistor 115. The transistor 115 acts as a driving element of the light-emitting diode 20, and adjusts the current passing through the light-emitting diode 20, thereby adjusting its luminous intensity. The base of the transistor 115 receives the control signal from the second switch module 114, and its collector is connected in series with the light-emitting diode 20 to form a current branch. According to the size of the base current, the transistor 115 adjusts the current between the collector and the emitter, and controls the luminous intensity of the light-emitting diode 20 by adjusting the current. The fourth switch module 121 controls the transmission path of the feedback signal, and determines whether the electrical signal generated by the photodiode is transmitted to the operational amplifier module. Under the control of the control module 104, the fourth switch module 121 can be turned on or off. When the fourth switch module 121 is turned on, the feedback signal of the first photodiode 123 can be transmitted to the third switch module 122 and further sent to the first operational amplifier module 113 for processing. The PWM control signal of the fourth switch module 121 and the second switch module 114 is the same, and the frequency and period are consistent. The first photodiode 123 converts the light signal emitted by the light emitting diode 20 into an electrical signal, providing real-time light intensity feedback information for the driving module 101. The first photodiode 123 converts the light signal into a voltage or current signal by sensing the light emitted by the light emitting diode 20.When the first photodiode 123 is illuminated by the light emitted by the light emitting diode 20, an electrical signal proportional to the light intensity is generated, and the signal is transmitted to the second input terminal of the first operational amplifier module 113 through the third switch module 122 and the fourth switch module 121. The first operational amplifier module 113 compares the signal with the reference signal to adjust the brightness of the light emitting diode 20.

[0057] The technical effect of this embodiment is that the various submodules in the driving module achieve precise control of the light-emitting diode by cooperating with each other. The first switch module and the filter module ensure the stability of the power supply, and the first operational amplifier module adjusts the light intensity of the light-emitting diode to meet the expectations through feedback. The cooperation of the second switch module and the transistor makes the adjustment process more flexible and efficient. On the whole, the driving module ensures that the light-emitting diode can maintain stable light output under different working conditions, effectively improving the accuracy and stability of the photoelectric sensing system.

[0058] As an example, Figure 3 As shown, pin 3 of the first switch module U3 is respectively connected to one end of the tenth resistor R10 and one end of the twentieth capacitor C20, the other end of the tenth resistor R10 and one end of the nineteenth capacitor C19 are connected together to receive the second voltage VCC5, the other end of the nineteenth capacitor C19, the other end of the twentieth capacitor C20 and pin 1 of the first switch module U3 are connected to the ground, the pin 5 of the first switch module U3 and one end of the eleventh capacitor C11 are connected together to receive the first voltage VCC4, the other end of the eleventh capacitor C11 is grounded, and the pin 4 of the first switch module U3 is connected to the input end of the filter module 112.

[0059] The filter module 112 includes a fourteenth resistor R14, a fifteenth resistor R15, a sixteenth resistor R16, a seventeenth resistor R17, a twenty-third capacitor C23, a twenty-fourth capacitor C24, a twenty-fifth capacitor C25 and a twenty-sixth capacitor C26; one end of the fourteenth resistor R14 is the input end of the filter module 112, the other end of the fourteenth resistor R14 is respectively connected to one end of the fifteenth resistor R15 and one end of the twenty-fourth capacitor C24, the other end of the fifteenth resistor R15 is respectively connected to one end of the sixteenth resistor R16 and one end of the twenty-sixth capacitor C26, the other end of the sixteenth resistor R16 is respectively connected to one end of the seventeenth resistor R17 and one end of the twenty-fifth capacitor C25, the other end of the seventeenth resistor R17 and one end of the twenty-third capacitor C23 are commonly connected as the output end of the filter module 112, and the other end of the twenty-third capacitor C23, the other end of the twenty-fourth capacitor C24, the other end of the twenty-fifth capacitor C25 and the other end of the twenty-sixth capacitor C26 are commonly connected to the ground.

[0060] The first operational amplifier module 113 is a first operational amplifier U4, the non-inverting input terminal of the first operational amplifier U4 is the first input terminal of the first operational amplifier module 113, the inverting input terminal of the first operational amplifier U4 is the second input terminal of the first operational amplifier module 113, the inverting input terminal of the first operational amplifier U4 is respectively connected to one end of the sixteenth capacitor C16, one end of the ninth capacitor C9, one end of the tenth capacitor C10, and the pin 3 of the third switch module U2A, the other end of the sixteenth capacitor C16 is grounded, the other end of the ninth capacitor C9 is grounded, and the pin 1 of the third switch module U2A is grounded. Pin 1 is connected to one end of the fourth capacitor C4 and receives the first voltage VCC4. The other end of the fourth capacitor C4 is grounded. Pin 2 of the third switch module U2A is connected to pin 10 of the third switch module U2B. Pin 9 of the fourth switch module U2B is respectively connected to the anode of the first photodiode D1 and one end of the second resistor R2. The other end of the second resistor R2 is grounded. The cathode of the first photodiode D1 and one end of the second capacitor C2 are connected to receive the first voltage VCC4. The power supply end of the first operational amplifier U4 is connected to one end of the fourteenth capacitor C14 and receives the first voltage VC. C4, the other end of the fourteenth capacitor C14 is grounded, the output end of the first operational amplifier U4 is respectively connected to one end of the twelfth resistor R12 and the other end of the tenth capacitor C10, the other end of the twelfth resistor R12 is respectively connected to one end of the twenty-first capacitor C21 and the pin 4 of the second switch module U6, the other end of the twenty-first capacitor C21 is grounded, the pin 6 of the second switch module U6 is connected to one end of the twentieth resistor R20, the other end of the twentieth resistor R20 is grounded, and the pin 5 of the second switch module U6 is connected to one end of the twenty-seventh capacitor C27 and receives the first voltage VCC 4. The other end of the twenty-seventh capacitor C27 is grounded, the pin 1 of the second switch module U6 is connected to the base of the transistor Q1, the collector of the transistor Q1 is connected to the cathode of the light-emitting diode D2, the anode of the light-emitting diode D2 is respectively connected to one end of the seventh capacitor C7 and one end of the seventh resistor R7, the other end of the seventh resistor R7 and one end of the fifth capacitor C5 are connected in common to receive the voltage VCC2, the other end of the seventh capacitor C7 and the other end of the fifth capacitor C5 are connected in common to the ground, the emitter of the transistor Q1 is connected to one end of the twenty-first resistor R21, and the other end of the twenty-first resistor R21 is grounded.

[0061] Among them, VCC5 is a stable DC power supply output by the power module, which is the power supply for controlling the light source. The nineteenth capacitor C19, the tenth resistor R10 and the twentieth capacitor C20 are combined into a resistance-capacitance filter, and the resistor is used to control the charging current size on the capacitor. The first switch module U3 is a switch, and the light-emitting diode D2 emits or turns off according to the control signal DAC_PWM output by the single-chip control module 104. The fourteenth resistor R14 and the twenty-fourth capacitor C24, the fifteenth resistor R15 and the twenty-sixth capacitor C26, the sixteenth resistor R16 and the twenty-fifth capacitor C25, the seventeenth resistor R17 and the twenty-third capacitor C23 can be regarded as four low-pass filters, and different resistance and capacitance values ​​can filter out electrical signals of unnecessary frequencies, and the electrical signals are input through the first operational amplifier U4 in positive phase. The second capacitor C2 is the filter capacitor of VCC4, and the first photodiode D1 starts the light intensity feedback effect. The second resistor R2 exists so that the first photodiode D1 generates a pulse wave similar to an N shape after being irradiated by light. The fourth switch module U2B is a reverse input switch for the feedback signal generated by the first photodiode D1 to the third switch module U2A. The function of the fourth switch module U2B is to make the frequency and period of the feedback signal generated by the first photodiode D1 consistent with the frequency and period of the light-emitting diode D2, which greatly eliminates the influence of ambient light. Specifically, the single-chip control module outputs LED_PWM, and the input frequency and period are consistent with the control light source. The output back end of the 1-pin of the first operational amplifier U4 is used to control the light source. According to the characteristics of the operational amplifier, it can be known that when the light source is too bright, the pulse signal generated by the first photodiode D1 will be input through the first operational amplifier U4 inverted to adjust the light source power supply output by the 1-pin of the first operational amplifier U4. The twelfth resistor R12 and the twenty-first capacitor C21 are combined into a low-pass filter to filter out unnecessary electrical signal frequencies. The second switch module U6 is a switch, and the single-chip module controls the switching cycle frequency of the second switch module U6 through LED_PWM to control the brightness of the light-emitting diode D2. The eighteenth resistor R18 is a pull-down resistor to prevent interference from misleading the transistor Q1, causing D2 to light up by mistake. The twenty-first resistor R21 is a current limiting resistor of the current loop of the light source D2. The fifth capacitor C5, the seventh resistor R7 and the seventh capacitor C7 form a resistor-capacitor filter, which is used to selectively block the transmission of a specific power supply frequency component.

[0062] The technical effect of this embodiment is that the circuit realizes precise control of the light-emitting diode and feedback adjustment of the light intensity, ensuring that the light source can maintain a constant brightness under different environmental conditions. The multi-stage filtering design effectively suppresses high-frequency noise and environmental interference, and improves the signal purity and reliability of the system. The protection measures of the current limiting resistor and the pull-down resistor ensure the safe operation of the circuit in a high-power and noisy environment.

[0063] In addition to the above structure, the driving module 101 may also include but is not limited to the following structure:

[0064] 1. Linear drive circuit: Use a linear regulator or operational amplifier to adjust the current and control the brightness of the light-emitting diode. The operational amplifier adjusts the output current according to the input signal so that the brightness of the LED is proportional to the input signal.

[0065] 2. Switching drive circuit (PWM control): Use pulse width modulation (PWM) signal to control the on and off of the switch element (such as MOSFET or transistor) to adjust the average current of the LED. By changing the duty cycle of the PWM signal, the brightness of the LED is adjusted.

[0066] 3. Constant current source drive circuit: constant current source design is adopted, and constant current is provided to drive LED through voltage regulator chip or dedicated constant current driver IC. Constant current source can automatically adjust the output voltage to keep the current constant. Features: stable current output can be provided within different input voltage ranges, ensuring that LED brightness is not affected by power supply fluctuations.

[0067] 4. Digital drive circuit (DAC control): Use a digital-to-analog converter (DAC) to generate an accurate voltage signal to control the LED drive current. The DAC output voltage is amplified or adjusted to directly drive the LED.

[0068] In addition to the above structure, the feedback module 102 may also include but is not limited to the following structure:

[0069] 1. Analog feedback control circuit: Use a photodiode or photoresistor to convert the light signal into current or voltage, and then directly feed it back to the operational amplifier input of the driving circuit to adjust the driving current.

[0070] 2. Optocoupler feedback circuit: Use an optocoupler to transmit the feedback signal of the photodiode to the drive circuit after isolating the optical signal. The phototransistor inside the optocoupler converts the optical signal back into an electrical signal to achieve isolated feedback.

[0071] 3. Proportional Integral Differential (PID) feedback circuit: The light intensity signal is obtained through a photodiode or photoresistor and transmitted to the controller. The controller uses the PID algorithm to adjust the drive signal according to the deviation between the set value and the feedback signal.

[0072] 4. Current feedback circuit: monitor the output current of the photodiode through a shunt resistor or Hall sensor, and perform feedback adjustment based on current changes.

[0073] As an implementation method, Figure 4As shown, the optical receiving module 103 includes a second photodiode 131, a first amplifying module 132 and a second amplifying module 133; the output end of the second photodiode 131 is connected to the input end of the first amplifying module 132, and the output end of the first amplifying module 132 is connected to the input end of the second amplifying module 133; the second photodiode 131 converts the optical signal into a second electrical signal, the first amplifying module 132 performs a first-stage amplification on the second electrical signal, and the second amplifying module 133 performs a second-stage amplification on the second electrical signal after the first-stage amplification and outputs a third electrical signal.

[0074] Among them, the second photodiode 131 converts the received optical signal into an electrical signal to indicate the change in light intensity. After receiving the optical signal emitted by the external light source, the second photodiode 131 converts the optical signal into a current or voltage signal (second electrical signal) that is proportional to the light intensity. Since the intensity of the optical signal is usually weak, the amplitude of the converted electrical signal is also low. The first amplification module 132 performs a primary amplification on the weak electrical signal generated by the second photodiode 131 to increase the signal amplitude so that it is suitable for subsequent secondary amplification and processing. The second amplification module 133 performs a secondary amplification on the electrical signal amplified by the first amplification module 132 to further increase the signal strength, and performs waveform optimization so that the output signal is suitable for subsequent numerical conversion and processing.

[0075] The technical effect of this embodiment is that the second photodiode provides accurate photoelectric conversion and can respond quickly to changes in external light sources. The first amplification module increases the intensity of weak light signals and performs preliminary shaping to reduce the impact of high-frequency noise. The second amplification module further enhances the signal amplitude, and through integration and filtering, makes the output signal smoother and more stable, which is suitable for subsequent data processing and analysis. This multi-stage amplification design enables the entire optical receiving module to maintain high-precision detection under weak light signals and can adapt to light environments of different intensities. Through precise signal amplification and optimization, the optical receiving module improves the sensitivity and reliability of the system and provides better performance for photoelectric detection applications.

[0076] As an implementation method, Figure 5As shown in the figure, the first amplification module 132 includes a second operational amplifier U5, a fifth resistor R5, a sixth resistor R6, a ninth resistor R9, an eleventh resistor R11, a twenty-third resistor R23, a twenty-fourth resistor R24, a twenty-fifth resistor R25, an eighth capacitor C8, a twelfth capacitor C12, a fifteenth capacitor C15, a twenty-second capacitor C22 and a twenty-eighth capacitor C28; one end of the ninth resistor R9 is connected to the first voltage VCC4, the other end of the ninth resistor R9 is respectively connected to one end of the eleventh resistor R11 and one end of the twenty-second capacitor C22, the other end of the twenty-second capacitor C22 is grounded, the other end of the eleventh resistor R11 and one end of the fifteenth capacitor C15 are commonly connected as the input end of the first amplification module 132, and the other end of the fifteenth capacitor C15 is respectively connected to one end of the fifth resistor R5, one end of the eighth capacitor C8 and the second The inverting input terminal of the operational amplifier U5 and the other end of the fifth resistor R5 are connected to one end of the sixth resistor R6, the power supply terminal of the second operational amplifier U5 is commonly connected with one end of the twelfth capacitor C12 and receive the first voltage VCC4, the other end of the twelfth capacitor C12 is grounded, the non-inverting input terminal of the second operational amplifier U5 is respectively connected to one end of the twenty-eighth capacitor C28, one end of the twenty-third resistor R23 and one end of the twenty-fourth resistor R24, the other end of the twenty-fourth resistor R24 ​​is connected to one end of the twenty-fifth resistor R25, the other end of the twenty-fifth resistor R25 receives the first voltage VCC4, the other end of the twenty-eighth capacitor C28 and the other end of the twenty-third resistor R23 are commonly connected to the ground, and the output terminal of the second operational amplifier U5, the other end of the sixth resistor R6 and the other end of the eighth capacitor C8 are commonly connected as the output terminal of the first amplification module 132.

[0077] Among them, the ninth resistor R9, the twenty-second capacitor C22 and the eleventh resistor R11 cooperate to eliminate the peak voltage. The second photodiode D4 generates a weak signal of an inverted triangle after receiving the emitted light. The control module 104 cannot directly collect the weak signal. Therefore, the back-stage circuit adds a two-stage signal amplification circuit. The second operational amplifier U5 combines the eleventh resistor R11, the fifteenth capacitor C15, the fifth resistor R5, the sixteenth resistor R6, and the eighth capacitor C8 to form a reverse proportional amplification circuit, but it is not completely a reverse proportional circuit. Among them, the fifteenth capacitor C15, the fifth resistor R5, and the sixth resistor R6 form a differential circuit. The eleventh resistor R11 cooperates with the fifth resistor R5 and the sixth resistor R6 to be regarded as an inverse proportional amplification relationship. Therefore, the waveform of the signal outputted by the output end of the second operational amplifier U5 is a positive slightly larger triangle-like peak wave, but due to the differential circuit, the waveform is inclined to the upper right, which is a first-stage amplified unprocessed signal. The twelfth capacitor C12 is a filter capacitor for the input power supply of the second operational amplifier U5. The series voltage divider circuit of the twenty-third resistor R23, the twenty-fourth resistor R24 ​​and the twenty-fifth resistor R25 cooperates with the filter capacitor to provide stable different reference voltages for the second operational amplifier U5 and the third operational amplifier U7.

[0078] The technical effect of this embodiment is that the first amplification module can not only effectively increase the amplitude of the input signal, but also optimize the shape and phase characteristics of the signal. By combining differentiation and reverse amplification, the output waveform is more in line with the system's requirements for signal processing, providing a more ideal signal input for secondary amplification and subsequent signal analysis.

[0079] It should be noted that, in addition to the above structure, the first amplifier module 132 may also include but is not limited to the following structures: proportional amplifier circuit, integral amplifier circuit, current feedback amplifier circuit, bipolar amplifier circuit, amplifier circuit with filter, differential amplifier circuit, etc.

[0080] As an implementation method, Figure 5As shown in the figure, the second amplification module 133 includes a third operational amplifier U7, a fifth switch module U1A, a sixth switch module U1B, a first resistor R1, a third resistor R3, an eighth resistor R8, a thirteenth resistor R13, a first capacitor C1, a third capacitor C3, a sixth capacitor C6, a thirteenth capacitor C13, a seventeenth capacitor C17 and a twenty-ninth capacitor C29; one end of the seventeenth capacitor C17 is connected to the output end of the first amplification module 132, the other end of the seventeenth capacitor C17 is connected to one end of the thirteenth resistor R13, the other end of the thirteenth resistor R13 is respectively connected to one end of the first resistor R1, one end of the third capacitor C3, one end of the third resistor R3, one end of the sixth capacitor C6, one end of the eighth resistor R8 and the inverting input end of the third operational amplifier U7, and the non-inverting input end of the third operational amplifier U7 is respectively connected One end of the twenty-ninth capacitor C29 and one end of the twenty-fifth resistor R25, and the other end of the twenty-ninth capacitor C29 is grounded, the output end of the third operational amplifier U7 is respectively connected to pin 3 of the fifth switch module U1A, pin 9 of the sixth switch module U1B, the other end of the sixth capacitor C6 and the other end of the eighth resistor R8, the power supply end of the third operational amplifier U7 and one end of the thirteenth capacitor C13 are connected together to receive the first voltage VCC4, the other end of the thirteenth capacitor C13 is grounded, pin 2 of the fifth switch module U1A is connected to the other end of the first resistor R1, pin 1 of the fifth switch module U1A and one end of the first capacitor C1 are connected together to receive the first voltage VCC4, the other end of the first capacitor C1 is grounded, and pin 10 of the sixth switch module U1B is respectively connected to the other end of the third capacitor C3 and the other end of the third resistor R3.

[0081] Among them, after the signal is amplified by the first amplification module 132, it passes through the seventeenth capacitor C17, and the seventeenth capacitor C17 filters out unnecessary high-frequency signal components, because there are unnecessary high-frequency signals at the start and end points of the waveform of a period after the signal is amplified by the first stage. The thirteenth capacitor C13 is the filter capacitor of the third operational amplifier U7. The third operational amplifier U7 cooperates with the resistors thirteenth resistor R13, eighteenth resistor R8, and sixth capacitor C6 to act as an inverse proportional amplifier. At the same time, the thirteenth resistor R13 and the sixth capacitor C6 cooperate to form an integration circuit. This signal operation process is intended to reversely amplify the signal waveform generated by the second photodiode D4 receiving light again, and the waveform output through the integration process has tended to the ideal waveform. The control module 104 can connect the first resistor R1 in parallel by outputting the AMP1_CON signal to the pin 4 of the fifth switch module U1A, and can connect the third resistor R3 and the third capacitor C3 in parallel by outputting the AMP0_CON signal to the pin 8 of the sixth switch module U1B. This circuit can cleverly achieve multi-stage switching amplification. By collecting the receiving and amplifying waveforms of the second photodiode D4 at different levels, high, medium and low signal output modes can be realized.

[0082] The technical effect of this embodiment is that the second amplification module realizes high-precision amplification and optimized processing of optical signals by integrating functions such as signal secondary amplification, integral smoothing, multi-level gain adjustment and high-frequency noise filtering. The module can output ideal signal waveforms under various input conditions, ensuring that the photoelectric sensor system can work stably under different light intensity conditions. The multi-level gain adjustment function provides flexibility, allowing the system to automatically adjust the amplification factor according to environmental changes, improving the adaptability and reliability of signal processing, thereby providing high-quality input signals for subsequent signal acquisition and analysis.

[0083] It should be noted that, in addition to the above structure, the second amplification module 133 may also include but is not limited to the following structures: an adjustable gain amplifier, a multi-stage cascade amplifier, a broadband amplifier, a differential amplifier structure, an automatic gain control amplifier (AGC), and the like.

[0084] Further, such as Figure 5 As shown in the figure, the optical receiving module 103 also includes a seventh switch module U8, an eighteenth capacitor C18, a thirtieth capacitor C30, a thirty-first capacitor C31, a nineteenth resistor R19, a twenty-second resistor R22, a twenty-seventh resistor R27, a third diode D3 and a fifth diode D5; one end of the eighteenth capacitor C18 is connected to the output end of the third operational amplifier U7, the other end of the eighteenth capacitor C18, one end of the seventh switch module U8, one end of the nineteenth resistor R19, the anode of the third diode D3 and the cathode of the fifth diode D5 are connected as the output end of the optical receiving module 103, and the other end of the seventh switch module U8 is connected to the output end of the optical receiving module 103. One end of the twenty-seventh resistor R27 and one end of the thirty-first capacitor C31 are respectively connected, the other end of the twenty-seventh resistor R27 receives the second voltage VCC5, the other end of the nineteenth resistor R19 is grounded, the other end of the thirty-first capacitor C31 is grounded, the control end of the seventh switch module U8 is connected to one end of the twenty-second resistor R22, the other end of the twenty-second resistor R22 is grounded, the power supply end of the seventh switch module U8 and one end of the thirtieth capacitor C30 are connected together to receive the first voltage VCC4, the other end of the thirtieth capacitor C30 is grounded, the cathode of the third diode D3 receives the second voltage VCC5, and the anode of the fifth diode D5 is grounded.

[0085] Among them, the eighteenth capacitor C18 lags the current to form a phase difference, which can affect the waveform of the current. By adjusting the capacitance of the eighteenth capacitor C18, the ideal signal waveform of the acquisition can be achieved. Because the signal output by the third operational amplifier U7 is reversely amplified, the ADC acquisition of the control module 104 is positive pressure, so a reference power supply needs to be provided during acquisition. The seventh switch module U8 is a single-pole double-throw switch. The control module 104 controls the AIN_CON foot to open the VCC4 power supply according to the required cycle and connect it to the output line of the third operational amplifier U7. When the second photodiode D4 has an output, the amplitude of the signal waveform will be pulled down from the amplitude of VCC4, and the ADC will collect this amplitude for numerical conversion and output. The thirtieth capacitor C30 is the filter capacitor of VCC4, the twenty-second resistor R22 is to prevent the signal from being output by mistake, and the thirty-first capacitor C31 is the filter of the seventh switch module U8 power input. The nineteenth resistor R19 is to maintain the stability of the input signal, which can eliminate the drift of the input signal and prevent the noise and other interference at the ADC input end from affecting the sampling result. The third diode D3 and the fifth diode D5 are Schottky barrier diodes to prevent signal overcharge.

[0086] The technical effect of this implementation is that the demand for high-precision optical signal acquisition is achieved by optimizing signal waveforms, stabilizing reference voltages, filtering and denoising, overcharge protection, and flexible acquisition control. The stability and reliability of the module in complex environments are ensured by adjusting phase differences, suppressing signal drift, and preventing misoperation. The overcharge protection integrated with Schottky barrier diodes further improves the safety of the circuit, making the optical receiving module suitable for use in a variety of optical detection application scenarios, and can provide high-quality signal input to the control system for further analysis and processing.

[0087] As an implementation method, Figure 6 As shown, the control module 104 is used to output control signals through different pins to control different modules. Figure 7As shown, the signal output module 105 includes a thirty-ninth resistor R39, a forty-second resistor R42, a forty-third resistor R43, a forty-fifth resistor R45, a sixth transistor Q6, a seventh diode D7 and an eighth voltage-stabilizing diode D8; one end of the thirty-ninth resistor R39 is the input end of the signal output module 105, the other end of the thirty-ninth resistor R39 is respectively connected to one end of the forty-second resistor R42 and the base of the sixth transistor Q6, the other end of the forty-second resistor R42 is grounded, the collector of the sixth transistor Q6 is respectively connected to the cathode of the seventh diode D7 and the cathode of the eighth voltage-stabilizing diode D8, the anode of the seventh diode D7 is the output end of the signal output module 105, the anode of the eighth voltage-stabilizing diode D8 is grounded, the emitter of the sixth transistor Q6 is connected to one end of the forty-third resistor R43, the other end of the forty-third resistor R43 is connected to one end of the forty-fifth resistor R45, and the other end of the forty-fifth resistor R45 is grounded.

[0088] Among them, the signal output module 105 is used to output the NPN signal. The principle of the NPN signal output is: the single-chip control module 104 outputs through the port OUTPUT, enables the base high level of the sixth transistor Q6, makes BE conductive, and thus BC conductive, the C level of the sixth transistor Q6 is pulled down, and the NPN signal is output. The thirty-ninth resistor R39 is a current limiting resistor, the forty-second resistor R42 is a pull-down resistor to prevent erroneous output, and the forty-third resistor R43 and the forty-fifth resistor R45 are connected in series to ensure the stability of the circuit during high-power output.

[0089] Further, such as Figure 6 As shown, the signal output module 105 also includes a thirty-first resistor R31, a forty-first resistor R41 and a seventh transistor Q7; one end of the forty-first resistor R41 is connected to the emitter of the sixth transistor 115, the other end of the forty-first resistor R41 is connected to the base of the seventh transistor Q7, the collector of the seventh transistor Q7 and one end of the thirty-first resistor R31 are connected together as the overcurrent detection end of the signal output module 105, the other end of the thirty-first resistor R31 receives the third voltage, and the emitter of the seventh transistor Q7 is grounded.

[0090] Among them, the overcurrent protection principle of the NPN signal output is: when the sixth transistor Q6 is turned on, a high level is generated between BE of the sixth transistor Q6, and when the output is overcurrent, the conduction condition of the seventh transistor Q7 is reached, thereby enabling the seventh transistor Q7 to be turned on. The C pole of the seventh transistor Q7 has a pull-up resistor R31, so the position is in a high level signal in the initial state. When the output is overcurrent, the C pole of the seventh transistor Q7 jumps from a high level signal to a low level signal, generating an overcurrent signal OCF.

[0091] The technical effect of this implementation is that the signal output module realizes the stable output, overcurrent protection and voltage clamping functions of the NPN signal through sophisticated circuit design. The use of current limiting resistors and pull-down resistors ensures the safety of signal output and avoids unnecessary output due to misoperation or external interference. The seventh diode and the eighth voltage regulator further provide voltage protection for the output end to prevent high voltage from damaging the circuit. The overall design of this technical solution ensures the stability and reliability of the signal output module under various working conditions and is suitable for a variety of application scenarios that require precise signal control.

[0092] It should be noted that, in addition to the above structure, the signal output module 105 may also include but is not limited to the following structures:

[0093] 1. PNP signal output module: Compared with NPN output, PNP signal output module uses PNP transistor. When the base level is low, the PNP transistor is turned on, so that the collector voltage is pulled high and a high level signal is output.

[0094] 2. MOSFET signal output module: Use N-type or P-type MOSFET as a switching device, and control the gate voltage to turn on or off the MOSFET to achieve signal output. N-type MOSFET is similar to NPN structure, while P-type MOSFET is similar to PNP structure.

[0095] 3. Optocoupler isolation signal output module: Use optical coupling devices (such as optical coupling relays) to isolate the control circuit and the output circuit. The control module sends out a light signal through the optical coupling device, and the photosensitive element inside the optical coupling device is turned on, thereby driving the NPN or PNP transistor at the output end.

[0096] 4. Relay signal output module: Use electromagnetic relays to realize the on-off control of the signal. When the control circuit is energized, the relay coil generates a magnetic field and closes the contacts, thereby controlling the on-off of the load.

[0097] Furthermore, the photoelectric sensor circuit also includes a power module, and the power module includes the following structure:

[0098] like Figure 8As shown, the anode of the ninth diode D9 is connected to the voltage VCC1, the cathode of the ninth diode D9 is connected to one end of the fuse F1, the other end of the fuse F1 is respectively connected to one end of the bidirectional transient suppression diode D10, one end of the forty-second capacitor C42, one end of the forty-fourth resistor R44 and pin 5 of the chip U11, the other end of the bidirectional transient suppression diode D10 is grounded, the other end of the forty-fourth resistor R44 is connected to pin 4 of the chip U11, the other end of the forty-second capacitor C42 and pin 2 of the chip U11 are connected to the ground, and the chip U11 Pin 6 of chip U1 is respectively connected to a first end of the first inductor L1, a cathode of the eleventh diode D11 and one end of the thirty-ninth capacitor C39, pin 1 of chip U11 is connected to the other end of the thirty-ninth capacitor C39, pin 3 of chip U11 is respectively connected to one end of the forty-sixth resistor R46 and one end of the forty-eighth resistor R48, the other end of the first inductor L1, the other end of the forty-sixth resistor R46, one end of the fortieth capacitor C40, one end of the forty-first capacitor C41, one end of the forty-third capacitor C43, one end of the forty-fourth capacitor C44 The output voltage VCC2 is outputted after the pin 4 of the chip U12, the anode of the eleventh diode D11, the other end of the forty-eighth resistor R48, the other end of the forty-third capacitor C43, and the other end of the forty-fourth capacitor C44 are connected to the ground, the other end of the forty-first capacitor C40, the other end of the forty-first capacitor C41, and the pin 2 of the chip U12 are connected to the ground, the pin 6 of the chip U12 is connected to one end of the second inductor L2, one end of the thirty-eighth capacitor C38, and the cathode of the twelfth diode D12, respectively. Pin 1 of chip U12 is connected to the other end of the thirty-eighth capacitor C38, pin 3 of chip U12 is respectively connected to one end of the forty-seventh resistor R47 and one end of the forty-ninth resistor R49, the other end of the second inductor L2, the other end of the forty-seventh resistor R47, one end of the forty-fifth capacitor C45 and one end of the forty-sixth capacitor C46 are connected together to output voltage VCC3, the anode of the twelfth diode D12, the other end of the forty-ninth resistor R49, the other end of the forty-fifth capacitor C45 and the other end of the forty-sixth capacitor C46 are connected together to ground.

[0099] like Fig. 9 As shown, pin 1, pin 3, one end of the forty-ninth capacitor C49 and one end of the fiftieth capacitor C50 of the chip U13 are connected together to receive the voltage VCC2, pin 2 of the chip U13, the other end of the forty-ninth capacitor C49 and the other end of the fiftieth capacitor C50 are connected together to ground, pin 5 of the chip U13, one end of the fifty-first capacitor C51 and one end of the fifty-second capacitor C52 are connected together to output the voltage VCC4, pin 4 of the chip U13 is connected to one end of the fifty-fifth capacitor C55, the other end of the fifty-first capacitor C51, the other end of the fifty-second capacitor C52 and the other end of the fifty-fifth capacitor C55 are connected together to ground.

[0100] like Fig.10 As shown, pin 1, pin 3, one end of the forty-seventh capacitor C47 and one end of the forty-eighth capacitor C48 of the chip U14 are connected together to receive the voltage VCC4, pin 2 of the chip U14, the other end of the forty-seventh capacitor C47 and the other end of the forty-eighth capacitor C48 are connected together to ground, pin 5 of the chip U14, one end of the fifty-third capacitor C53 and one end of the fifty-fourth capacitor C54 are connected together to output the voltage VCC5, pin 4 of the chip U14 is connected to one end of the fifty-sixth capacitor C56, the other end of the fifty-third capacitor C53, the other end of the fifty-fourth capacitor C54 and the other end of the fifty-sixth capacitor C56 are connected together to ground.

[0101] Since different modules in the photoelectric sensor circuit require multiple levels to coordinate the driving circuit, and there is only a single VCC1 input source, two step-down chips, chip U11 and chip U12, are used to reduce the power consumption of the entire power supply system, because the power conversion efficiency of chip U11 and chip U12 is extremely high, and the output power can meet the needs of the power supply system. Chip U13 and chip U14 are linear voltage regulator LDO chips, and the voltage output by linear voltage regulator is more stable, which can supply circuits that require special stable power supply.

[0102] Embodiment 2

[0103] The second embodiment provides a photoelectric sensor, including the photoelectric sensor circuit and light emitting diode provided in the first embodiment.

[0104] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention, and should be included in the protection scope of the present invention.

Claims

1. A photoelectric sensor circuit, characterized in that: include: A driving module, connected to the light emitting diode, and used to drive the light emitting diode to emit a light signal; a feedback module, connected to the driving module, configured to convert the optical signal into a first electrical signal and output the first electrical signal to the driving module; an optical receiving module, used for converting the optical signal into a second electrical signal, and amplifying the second electrical signal to output a third electrical signal; a control module and a signal output module, wherein the control module is respectively connected to the driving module, the feedback module, the light receiving module and the signal output module, and is used to control the driving module to drive the light emitting diode according to a preset frequency, control the feedback module to adjust the brightness of the light emitting diode, and receive the third electrical signal and control the signal output module to output a signal according to the third electrical signal; The driving module includes a first switch module, a filter module, a first operational amplifier module, a second switch module and a triode, and the feedback module includes a third switch module, a fourth switch module and a first photodiode; One end of the first switch module receives the power supply voltage, the other end of the first switch module is connected to the input end of the filter module, the output end of the filter module is connected to the first input end of the first operational amplifier module, the second input end of the first operational amplifier module is connected to one end of the third switch module, the other end of the third switch module is connected to one end of the fourth switch module, the other end of the fourth switch module is connected to the anode of the first photodiode, the output end of the first operational amplifier module is connected to one end of the second switch module, the other end of the second switch module is connected to the base of the transistor, and the transistor and the light-emitting diode form a first current branch; The control module is connected to the control end of the first switch module, the control end of the second switch module, the control end of the third switch module and the control end of the fourth switch module respectively, and the control module controls the first switch module and the second switch module to make the light emitting diode emit light at a preset frequency, and controls the third switch module and the fourth switch module to adjust the brightness of the light emitting diode; The PWM control signals of the second switch module and the fourth switch module are the same, and the frequencies and periods are consistent.

2. The photoelectric sensor circuit according to claim 1, characterized in that: The filtering module includes a fourteenth resistor, a fifteenth resistor, a sixteenth resistor, a seventeenth resistor, a twenty-third capacitor, a twenty-fourth capacitor, a twenty-fifth capacitor and a twenty-sixth capacitor; One end of the fourteenth resistor is the input end of the filtering module, the other end of the fourteenth resistor is respectively connected to one end of the fifteenth resistor and one end of the twenty-fourth capacitor, the other end of the fifteenth resistor is respectively connected to one end of the sixteenth resistor and one end of the twenty-sixth capacitor, the other end of the sixteenth resistor is respectively connected to one end of the seventeenth resistor and one end of the twenty-fifth capacitor, the other end of the seventeenth resistor and one end of the twenty-third capacitor are commonly connected as the output end of the filtering module, and the other ends of the twenty-third capacitor, the twenty-fourth capacitor, the twenty-fifth capacitor and the twenty-sixth capacitor are commonly connected to ground.

3. The photoelectric sensor circuit according to claim 1, characterized in that: The light receiving module includes a second photodiode, a first amplifying module and a second amplifying module; The output end of the second photodiode is connected to the input end of the first amplifying module, and the output end of the first amplifying module is connected to the input end of the second amplifying module; The second photodiode converts the optical signal into a second electrical signal, the first amplification module performs a first-stage amplification on the second electrical signal, and the second amplification module performs a second-stage amplification on the first-stage amplified second electrical signal and outputs a third electrical signal.

4. The photoelectric sensor circuit according to claim 3, characterized in that: The first amplification module includes a second operational amplifier, a fifth resistor, a sixth resistor, a ninth resistor, an eleventh resistor, a twenty-third resistor, a twenty-fourth resistor, a twenty-fifth resistor, an eighth capacitor, a twelfth capacitor, a fifteenth capacitor, a twenty-second capacitor and a twenty-eighth capacitor; One end of the ninth resistor is connected to the first voltage, the other end of the ninth resistor is respectively connected to one end of the eleventh resistor and one end of the twenty-second capacitor, the other end of the twenty-second capacitor is grounded, the other end of the eleventh resistor and one end of the fifteenth capacitor are commonly connected to the input end of the first amplification module, the other end of the fifteenth capacitor is respectively connected to one end of the fifth resistor, one end of the eighth capacitor and the inverting input end of the second operational amplifier, the other end of the fifth resistor is connected to one end of the sixth resistor, the power supply end of the second operational amplifier is commonly connected to one end of the twelfth capacitor and receives the first voltage, the other end of the twelfth capacitor is grounded, the non-inverting input end of the second operational amplifier is respectively connected to one end of the twenty-eighth capacitor, one end of the twenty-third resistor and one end of the twenty-fourth resistor, the other end of the twenty-fourth resistor is connected to one end of the twenty-fifth resistor, the other end of the twenty-fifth resistor receives the first voltage, the other end of the twenty-eighth capacitor and the other end of the twenty-third resistor are commonly connected to the ground, and the output end of the second operational amplifier, the other end of the sixth resistor and the other end of the eighth capacitor are commonly connected to the output end of the first amplification module.

5. The photoelectric sensor circuit according to claim 4, characterized in that: The second amplification module includes a third operational amplifier, a fifth switch module, a sixth switch module, a first resistor, a third resistor, an eighth resistor, a thirteenth resistor, a first capacitor, a third capacitor, a sixth capacitor, a thirteenth capacitor, a seventeenth capacitor and a twenty-ninth capacitor; One end of the seventeenth capacitor is connected to the output end of the first amplification module, the other end of the seventeenth capacitor is connected to one end of the thirteenth resistor, the other end of the thirteenth resistor is respectively connected to one end of the first resistor, one end of the third capacitor, one end of the third resistor, one end of the sixth capacitor, one end of the eighth resistor and the inverting input end of the third operational amplifier, the non-inverting input end of the third operational amplifier is respectively connected to one end of the twenty-ninth capacitor and one end of the twenty-fifth resistor, the other end of the twenty-ninth capacitor is grounded, the output end of the third operational amplifier is respectively connected to one end of the fifth switch module, one end of the sixth switch module, the other end of the sixth capacitor and the other end of the eighth resistor, the power supply end of the third operational amplifier and one end of the thirteenth capacitor are connected in common to receive the first voltage, the other end of the thirteenth capacitor is grounded, the other end of the fifth switch module is connected to the other end of the first resistor, the power supply end of the fifth switch module and the first end of the first capacitor are connected in common to receive the first voltage, the other end of the first capacitor is grounded, and the other end of the sixth switch is respectively connected to the other end of the third capacitor and the other end of the third resistor.

6. The photoelectric sensor circuit according to claim 5, characterized in that: The optical receiving module further includes a seventh switch module, an eighteenth capacitor, a thirtieth capacitor, a thirty-first capacitor, a nineteenth resistor, a twenty-second resistor, a twenty-seventh resistor, a third diode and a fifth diode; One end of the eighteenth capacitor is connected to the output end of the third operational amplifier, the other end of the eighteenth capacitor, one end of the seventh switch module, one end of the nineteenth resistor, the anode of the third diode and the cathode of the fifth diode are connected together as the output end of the optical receiving module, the other end of the seventh switch module is respectively connected to one end of the twenty-seventh resistor and one end of the thirty-first capacitor, the other end of the twenty-seventh resistor receives the second voltage, the other end of the nineteenth resistor is grounded, the other end of the thirty-first capacitor is grounded, the control end of the seventh switch module is connected to one end of the twenty-second resistor, the other end of the twenty-second resistor is grounded, the power supply end of the seventh switch module and one end of the thirtieth capacitor are connected together to receive the first voltage, the other end of the thirtieth capacitor is grounded, the cathode of the third diode receives the second voltage, and the anode of the fifth diode is grounded.

7. The photoelectric sensor circuit according to claim 1, characterized in that: The signal output module includes a thirty-ninth resistor, a forty-second resistor, a forty-third resistor, a forty-fifth resistor, a sixth transistor, a seventh diode and an eighth voltage regulator; One end of the thirty-ninth resistor is the input end of the signal output module, the other end of the thirty-ninth resistor is respectively connected to one end of the forty-second resistor and the base of the sixth transistor, the other end of the forty-second resistor is grounded, the collector of the sixth transistor is respectively connected to the cathode of the seventh diode and the cathode of the eighth voltage-regulating diode, the anode of the seventh diode is the output end of the signal output module, the anode of the eighth voltage-regulating diode is grounded, the emitter of the sixth transistor is connected to one end of the forty-third resistor, the other end of the forty-third resistor is connected to one end of the forty-fifth resistor, and the other end of the forty-fifth resistor is grounded.

8. The photoelectric sensor circuit according to claim 7, characterized in that: The signal output module also includes a thirty-first resistor, a forty-first resistor and a seventh transistor; One end of the forty-first resistor is connected to the emitter of the sixth transistor, the other end of the forty-first resistor is connected to the base of the seventh transistor, the collector of the seventh transistor and one end of the thirty-first resistor are connected together as the overcurrent detection end of the signal output module, the other end of the thirty-first resistor receives the third voltage, and the emitter of the seventh transistor is grounded.

9. A photoelectric sensor, characterized in that: include: The photoelectric sensor circuit and light emitting diode according to any one of claims 1 to 8.

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