Protective device for photoelectric detector assembly

Abstract

The invention belongs to the technical field of photoelectric detectors, and particularly discloses a protection device for a photoelectric detector assembly, which comprises a positive and negative power supply high and low voltage protection module forming multiple paths, and the protection module comprises a load switch, a sampler, a comparator and a control logic module, the load switches are installed between a fuse and a load of a load circuit, the sampler is used for sampling load voltage, the comparators are used for comparing the sampled load voltage with reference voltage, and the control logic module is used for receiving output signals of the comparators and controlling on-off of the load switches. The multi-channel overvoltage and overcurrent protection problem of positive low voltage, negative low voltage and negative high voltage and the over-temperature protection problem caused by too high environment temperature are successfully solved in one device, multiple purposes of one machine are achieved, and the size and complexity of the system are reduced.

Description

Technical Field

[0001] This invention belongs to the field of photodetector technology, and in particular relates to a protection device for a photodetector assembly. Background Technology

[0002] Photodetector assemblies are core components in fields such as fuses, guidance, and detection. LiDAR detectors rely on a laser to emit laser light, which the detector then receives the reflected laser echo signal from the target. Utilizing the photoelectric effect, the optical signal is converted into an electrical signal, achieving photoelectric conversion. After processing by a preamplifier circuit, an electrical pulse signal with a specific pulse width is formed, while simultaneously achieving attenuation in the preamplifier circuit. The photodiodes in these detector assemblies typically operate at a specific high negative voltage, while the subsequent operational amplifier operates at both positive and negative voltages. Furthermore, these detector assemblies are inherently very fragile, extremely sensitive to overcurrent and overvoltage; even minor electrical shocks can cause permanent damage.

[0003] In practical applications and testing, overvoltage or overcurrent pulses can easily be introduced due to power-on transients, operational errors (such as incorrect wiring), electrostatic discharge, or external interference, causing irreversible damage to expensive photoelectric detection components. While existing technologies offer simple overcurrent and overvoltage protection solutions such as fuses, TVS diodes, or power supply chips with overcurrent and overvoltage protection, they suffer from the following drawbacks: 1. Limited protection solutions: Traditional protection circuits are usually designed for a single voltage level, making it difficult to simultaneously and optimally handle positive low voltage, negative low voltage, and extremely high negative voltage in the same device.

[0004] 2. High voltage processing is complex: For high voltages such as -600V, the common practice is to use complex level shifting circuits or high voltage differential amplifiers for sampling, which results in complex circuits, high costs and reduced reliability.

[0005] 3. Inconvenient negative voltage handling: For negative voltage circuits such as -15V, additional negative voltage conversion circuits or operational amplifiers are usually required, which increases the number of components and design complexity.

[0006] 4. Low system integration: There is a lack of unified and reliable linkage control logic between multiple independent protection circuits, and the fault state holding and reset mechanism is not simple and reliable enough.

[0007] Therefore, there is an urgent need for a multi-channel voltage protection solution that can provide fast, accurate, automatic recovery, and integrated protection for photodetector components. Summary of the Invention

[0008] In view of this, the purpose of the present invention is to provide an integrated multi-channel overvoltage, overcurrent and overtemperature protection device that can simultaneously provide comprehensive protection for the positive low voltage, negative low voltage and high negative voltage power supply paths of the photodetector assembly, and can also detect the ambient temperature of the device under test. Once the ambient temperature exceeds the preset ambient temperature, the power supply to the device under test will be immediately cut off.

[0009] To achieve the above objectives, the present invention provides the following technical solution: This invention provides a protection device for a photodetector assembly, comprising a multi-channel positive and negative power supply high and low voltage protection module, the protection module comprising: A load switch, wherein the load switch is installed between the fuse and the load in the load circuit; A sampler for sampling load voltage; A comparator for comparing a sampled load voltage with a reference voltage; The control logic module is used to receive the output signals of each comparator and control the on / off state of each load switch.

[0010] Furthermore, the protection device includes a positive power supply low-voltage protection module, a negative power supply low-voltage protection module, and a negative power supply high-voltage protection module. The positive power supply low voltage protection module includes a first load switch, a first sampler, and a first comparator. The positive power supply low voltage is output to the load through a first fuse and a first load switch. The first sampler samples the voltage at the output terminal of the first load switch and sends it to the first comparator. The first comparator compares the voltage at the output terminal of the first load switch with a reference voltage and outputs a signal to the control logic module. The negative power supply low voltage protection module includes a second load switch, a second sampler, and a second comparator. The negative power supply low voltage is output to the load through a second fuse and a second load switch. The second sampler samples the voltage at the output terminal of the second load switch and sends it to the second comparator. The second comparator compares the voltage at the output terminal of the second load switch with a reference voltage and outputs a signal to the control logic module. The negative power supply high voltage protection module includes a third load switch, a third sampler, and a third comparator. The negative power supply high voltage is output to the load through a third fuse and a third load switch. The third sampler samples the voltage at the output terminal of the third load switch and sends it to the third comparator. The third comparator compares the voltage at the output terminal of the third load switch with a reference voltage and outputs a signal to the control logic module. The control logic module receives the output signals of the first comparator, the second comparator, and the third comparator, and controls the on / off state of the first load switch, the second load switch, and the third load switch in a unified manner.

[0011] Furthermore, the protection device also includes an over-temperature protection module, which includes a temperature sensor, a fourth sampler, and a fourth comparator. The temperature sensor is used to detect the ambient temperature of the device under test in real time and convert the detection signal into an electrical signal. The fourth sampler samples the electrical signal output by the temperature sensor and sends it to the fourth comparator. The fourth comparator compares the electrical signal output by the temperature sensor with a reference voltage and outputs a signal to the control logic module. The control logic module uniformly controls the on / off state of each load switch.

[0012] Furthermore, the protection device also includes a status indicator light. The comparator, the status indicator light, and the control logic module form a separate loop, and the comparator output signal drives the status indicator light.

[0013] Furthermore, the load switch adopts an optical MOS relay, the first load switch and the second load switch adopt an optical MOS relay AQV252G, and the third load switch adopts an optical MOS relay AQV259AX.

[0014] Furthermore, the sampler uses two or more series resistors for voltage division sampling.

[0015] Furthermore, the comparator employs a comparator TLV1701 that supports negative voltage input.

[0016] Furthermore, the control logic module is an RS latch composed of a digital logic chip CD4011.

[0017] Furthermore, the control logic module is equipped with a manual reset button.

[0018] Furthermore, the temperature sensor used is an LM35.

[0019] Compared with the prior art, the present invention has the following significant advantages: 1. Multi-channel integration: This invention first samples the load voltage of each channel using a sampler, then compares the sampled load voltage with a reference voltage using a comparator, and finally, the control logic module controls the on / off state of each load switch using the fault signal output by the comparator. This successfully solves the protection problems of positive low voltage, negative low voltage, and high negative voltage within a single device. Simultaneously, this device also incorporates an over-temperature protection module. A temperature sensor detects the ambient temperature of the load, and the sampler samples the electrical signal converted by the temperature sensor. Finally, the comparator compares this signal with a reference voltage and outputs a fault signal. If the ambient temperature is detected to be higher than a preset value, the control logic module controls each switch to disconnect, protecting the device under test (DUT) and preventing damage due to excessively high ambient temperature. In short, this invention successfully solves the protection problems of multiple channels for positive low voltage, negative low voltage, and negative high voltage, as well as the over-temperature protection problem caused by excessively high ambient temperature, within a single device, achieving multiple functions in one unit and reducing system size and complexity.

[0020] 2. Simplified high-voltage protection: This device innovatively adopts the "high-power series resistor voltage divider sampling" scheme, which avoids the cost, size and failure rate problems caused by complex high-voltage processing circuits. The extremely simple circuit realizes safe and reliable sampling of -600V high voltage.

[0021] 3. Direct negative pressure processing: This device innovatively uses a comparator that supports negative pressure input, realizing direct detection of negative pressure lines without the need for additional signal conditioning circuits, simplifying the design and improving response speed and reliability.

[0022] 4. Reliable control logic: This device uses latching logic built with dedicated digital chips. Compared with logic implemented by discrete components or software, it has stronger anti-interference ability, maintains stable state, and ensures deterministic fault response.

[0023] 5. Easy maintenance: Overcurrent is controlled by fuse blowing, and overvoltage is controlled by latching logic built with a dedicated digital chip to control the load switches of each circuit. In conjunction with the LED status indicators of each circuit, the fault phenomenon is clearly identified. At the same time, the latch is equipped with a manual reset button, which can be used to reset, making it simple to locate and restore, reducing the maintenance threshold and time.

[0024] 6. High configurability and flexibility: Users can flexibly set the protection thresholds of each channel through software to adapt to different models and operating points of photodetectors, which greatly enhances the versatility of the device. One device can serve a variety of application scenarios.

[0025] Other advantages, objectives, and features of the invention will be set forth in part in the description which follows, and in part will be apparent to those skilled in the art from the following examination, or may be learned from practice of the invention. The objectives and other advantages of the invention can be realized and obtained through the following description. Attached Figure Description

[0026] To make the objectives, technical solutions, and advantages of the present invention clearer, the preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings, wherein: Figure 1 This is a schematic diagram of the functional modules of a multi-channel overvoltage and overcurrent protection device. Figure 2 Schematic diagram of positive power supply low voltage protection module; Figure 3 Schematic diagram of a negative power supply low-voltage protection module; Figure 4 Schematic diagram of negative power supply high voltage protection module; Figure 5 This is a schematic diagram of the over-temperature protection module; Figure 6 This is a schematic diagram of the control and reset logic of the present invention.

[0027] Reference numerals: 1-Positive power supply low voltage protection module, 11-First fuse, 12-First load switch, 13-First sampler, 14-First comparator, 2-Negative power supply low voltage protection module, 21-Second fuse, 22-Second load switch, 23-Second sampler, 24-Second comparator, 3-Negative power supply high voltage protection module, 31-Third fuse, 32-Third load switch, 33-Third sampler, 34-Third comparator, 4-Over-temperature protection module, 41-Temperature sensor, 42-Fourth sampler, 43-Fourth comparator, 5-Control logic module, 6-Manual reset button, 7a-Positive low voltage fault status indicator, 7b-Negative low voltage fault status indicator, 7c-Negative high voltage fault status indicator, 7d-Over-temperature fault status indicator. Detailed Implementation

[0028] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of the present invention. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0029] The accompanying drawings are for illustrative purposes only and are schematic diagrams, not actual photographs, and should not be construed as limiting this patent. To better illustrate the embodiments of the invention, some components in the drawings may be omitted, enlarged, or reduced, and do not represent the actual dimensions of the product. It is understandable to those skilled in the art that some well-known structures and their descriptions may be omitted in the drawings. Furthermore, reference numerals and / or letters may be repeated in different examples. Such repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed.

[0030] like Figure 1 As shown, this invention is a protection device for photoelectric detection components, including multiple parallel positive and negative power supply high and low voltage protection modules. The protection module includes a load switch, a sampler, a comparator, and a control logic module. The load switch is installed between the fuse and the load in the load circuit. The sampler is used to sample the load voltage at the output terminal of the load switch. The comparator compares the sampled load voltage with a reference voltage and outputs a fault signal to the control logic module. The control logic module is used to receive the output signals of each comparator and uniformly control the on / off state of each load switch.

[0031] The protection device of the present invention first samples the load voltage of each circuit through a sampler, then compares the sampled load voltage with the reference voltage through a comparator, and finally the control logic module controls the on / off state of each load switch through the fault signal output by the comparator. It successfully solves the protection problem of positive and negative power supply high and low voltage in one device, realizes multiple uses of one device, and reduces the system size and complexity.

[0032] Example 1 like Figure 1-6 As shown, the protection device in this embodiment includes a positive power supply low-voltage protection module 1, a negative power supply low-voltage protection module 2, and a negative power supply high-voltage protection module 3, wherein... The positive power supply low voltage protection module 1 includes a first load switch 12, a first sampler 13, and a first comparator 14. The +15V positive power supply low voltage is output to the load through the first fuse 11 and the first load switch 12. The first sampler 13 samples the voltage at the output terminal of the first load switch 12 and sends it to the first comparator 14. The first comparator 14 compares the voltage at the output terminal of the first load switch 12 with the reference voltage. If the voltage at the output terminal of the first load switch 12 exceeds the reference voltage, the first comparator 14 outputs a fault signal to the control logic module 5. The negative power supply low voltage protection module 2 includes a second load switch 22, a second sampler 23, and a second comparator 24. The -15V negative power supply low voltage is output to the load through the second fuse 21 and the second load switch 22. The second sampler 23 samples the voltage at the output terminal of the second load switch 22 and sends it to the second comparator 24. The second comparator 24 compares the voltage at the output terminal of the second load switch 22 with the reference voltage. If the voltage at the output terminal of the second load switch 22 exceeds the reference voltage, the second comparator 24 outputs a fault signal to the control logic module 5. The negative power supply high voltage protection module 3 includes a third load switch 32, a third sampler 33, and a third comparator 34. The -600V negative power supply high voltage is output to the load through the third fuse 31 and the third load switch 32. The third sampler 33 samples the voltage at the output terminal of the third load switch 32 and sends it to the third comparator 34. The third comparator 34 compares the voltage at the output terminal of the third load switch 32 with the reference voltage. If the voltage at the output terminal of the third load switch 32 exceeds the reference voltage, the third comparator 34 outputs a fault signal to the control logic module 5. The control logic module 5 receives fault signals output by the first comparator 14, the second comparator 24 and the third comparator 34. When it detects that the voltage of one of the loads exceeds the reference voltage, the control logic module 5 promptly controls the first load switch 12, the second load switch 22 and the third load switch 32 to disconnect, thereby providing overcurrent and overvoltage protection.

[0033] This embodiment solves the problem of protection against multiple overvoltage and overcurrent paths, including positive low voltage, negative low voltage, and negative high voltage, within a single device. Furthermore, by setting the protection threshold for each path, it can adapt to photodetectors of different models and operating points, thereby increasing the versatility of the protection device.

[0034] Example 2 like Figure 1 and Figure 5 As shown, this embodiment adds an over-temperature protection module 4 based on embodiment 1. The over-temperature protection module 4 includes a temperature sensor 41, a fourth sampler 42, and a fourth comparator 43. The temperature sensor 41 is used to detect the ambient temperature of the device under test in real time and convert the detection signal into an electrical signal. The fourth sampler 42 samples the electrical signal output by the temperature sensor and sends it to the fourth comparator 43. The fourth comparator 43 compares the electrical signal output by the temperature sensor 41 with a reference voltage. If the electrical signal output by the temperature sensor 41 exceeds the reference voltage, the fourth comparator 43 outputs a fault signal to the control logic module 5. The control logic module 5 promptly controls the disconnection of each load switch, thereby achieving the over-temperature protection function.

[0035] Example 3 like Figure 2-5As shown, this embodiment adds status indicator lights to each protection module based on Embodiments 1 and 2. Specifically, a positive low-voltage fault status indicator light 7a is added to the positive low-voltage protection module 1, a negative low-voltage fault status indicator light 7b is added to the negative low-voltage protection module 2, a negative high-voltage fault status indicator light 7c is added to the negative high-voltage protection module 3, and an over-temperature fault status indicator light 7d is added to the over-temperature protection module 4. Each fault status indicator light, together with the corresponding comparator and control logic module, forms a separate fault display circuit. The comparator output signal drives the status indicator light. In this way, the fault phenomenon can be clearly identified by the display status of each fault status indicator light.

[0036] Temperature sensor 41 uses LM35, which is a commonly used low-power, low-cost, high-precision temperature sensor that displays values ​​in the form of output voltage rather than degrees Celsius. This allows the comparison between the output voltage of temperature sensor 41 and the reference voltage to determine whether the ambient temperature of the load exceeds the set threshold. If the ambient temperature is detected to be higher than the preset value, the control logic module 5 controls each load switch to disconnect to protect the device under test and prevent damage to the device under test due to excessively high ambient temperature.

[0037] In the above embodiments, the load switch adopts an optical MOS relay. The optical MOS relay is a high-performance electronic control component, mainly composed of light-emitting diodes and MOSFETs. It adopts opto-isolation technology and has the advantages of small size, light weight, easy driving, fast switching speed and high reliability. Specifically, the first load switch 12 and the second load switch 22 adopt optical MOS relay AQV252G, and the third load switch 32 adopts optical MOS relay AQV259AX.

[0038] In the above embodiments, the sampler uses two or more series resistors to form a voltage divider for sampling. Specifically, the first sampler 13 uses two series resistors (R1, R2) to form a first voltage divider network for sampling, the second sampler 23 uses two series resistors (R3, R4) to form a second voltage divider network for sampling, and the third sampler 33 uses four high-power, high-voltage series resistors (R5, R6, R7, R8) to form a third voltage divider network for sampling. This sampling method can directly divide the -600V high voltage to a low voltage range that the comparator can handle, eliminating the need for complex front-end amplification or level shifting circuits, and avoiding the cost, size, and failure rate problems caused by complex high voltage processing circuits. The extremely simple circuit achieves safe and reliable sampling of -600V high voltage.

[0039] In the above embodiment, the comparator uses the TLV1701 comparator that supports negative voltage input. After the output is sampled through a voltage divider resistor network, it is directly sent to the inverting input of the comparator and compared with the reference voltage. This eliminates the need for a negative voltage conversion circuit, realizes direct detection of negative voltage lines, eliminates the need for additional signal conditioning circuits, simplifies the design, and improves response speed and reliability.

[0040] In the above embodiment, the control logic module 5 is an RS latch composed of a digital logic chip CD4011. It receives fault signals from three comparators. When any fault signal is valid, the latch is triggered to lock the fault state and output a control signal to simultaneously cut off the three optical MOS relays.

[0041] In the above embodiment, the control logic module 5 is provided with a manual reset button 6, which is connected to the reset terminal of the latch and is used to clear the latch state and restore normal operation after the fault is cleared.

[0042] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A protective device for a photodetector assembly, characterized in that, It includes a multi-channel positive and negative power supply high and low voltage protection module, a logic control module, and an over-temperature protection module. The positive and negative power supply high and low voltage protection module includes a positive power supply low voltage protection module, a negative power supply low voltage protection module, and a negative power supply high voltage protection module. The positive power supply low voltage protection module includes a first load switch, a first sampler, and a first comparator. The positive power supply low voltage is output to the load through a first fuse and a first load switch. The first sampler samples the voltage at the output terminal of the first load switch and sends it to the first comparator. The first comparator compares the voltage at the output terminal of the first load switch with a reference voltage and outputs a signal to the control logic module. The negative power supply low voltage protection module includes a second load switch, a second sampler, and a second comparator. The negative power supply low voltage is output to the load through a second fuse and a second load switch. The second sampler samples the voltage at the output terminal of the second load switch and sends it to the second comparator. The second comparator compares the voltage at the output terminal of the second load switch with a reference voltage and outputs a signal to the control logic module. The negative power supply high voltage protection module includes a third load switch, a third sampler, and a third comparator. The negative power supply high voltage is output to the load through a third fuse and a third load switch. The third sampler samples the voltage at the output terminal of the third load switch and sends it to the third comparator. The third comparator compares the voltage at the output terminal of the third load switch with a reference voltage and outputs a signal to the control logic module. The control logic module receives the output signals of the first comparator, the second comparator, and the third comparator, and controls the on / off state of the first load switch, the second load switch, and the third load switch in a unified manner. The over-temperature protection module includes a temperature sensor, a fourth sampler, and a fourth comparator. The temperature sensor is used to detect the ambient temperature of the device under test in real time and convert the detection signal into an electrical signal. The fourth sampler samples the electrical signal output by the temperature sensor and sends it to the fourth comparator. The fourth comparator compares the electrical signal output by the temperature sensor with a reference voltage and outputs a signal to the control logic module. The control logic module controls the on / off state of each load switch.

2. The protective device for a photodetector assembly according to claim 1, characterized in that, It also includes a status indicator light. The comparator, the status indicator light, and the control logic module form a separate loop. The comparator output signal drives the status indicator light.

3. The protective device for a photodetector assembly according to claim 1, characterized in that, The load switch is an optical MOS relay, the first load switch and the second load switch are optical MOS relays AQV252G, and the third load switch is an optical MOS relay AQV259AX.

4. The protective device for a photodetector assembly according to claim 1, characterized in that, The sampler uses two or more series resistors for voltage division sampling.

5. The protective device for a photodetector assembly according to claim 1, characterized in that, The comparator used is the TLV1701 comparator, which supports negative voltage input.

6. The protective device for a photodetector assembly according to claim 1, characterized in that, The control logic module is an RS latch composed of a CD4011 digital logic chip.

7. The protective device for a photodetector assembly according to claim 1, characterized in that, The control logic module is equipped with a manual reset button.

8. The protective device for a photodetector assembly according to claim 1, characterized in that, The temperature sensor used is an LM35.

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