A non-contact electromagnetic compatibility detection device

Abstract

The application provides a non-contact electromagnetic compatibility detection device, which comprises a receiving unit and a handheld display unit; wherein the receiving unit comprises signal receiving, signal sampling, signal classification, analog-digital conversion, code pattern formation, code pattern output display, a microprocessor and a storage; the handheld display unit comprises photoelectric conversion, code pattern decoding recovery, code pattern comparison and selection, code pattern parameter display, a microprocessor, a storage and a keyboard; the application adopts a non-contact light scanning test form for the equipment to be tested, can reduce the influence of related wire string interference signals on detection data, can directly determine the type of interference source and output related parameters, is suitable for occasions requiring non-contact equipment electromagnetic compatibility detection, can avoid direct contact between detection personnel and the equipment to be tested, reduce harm to human body, can realize corresponding detection on the equipment to be tested which is not easy to move, and fills the blank of equipment electromagnetic compatibility detection which cannot capture electromagnetic interference signals by using light signals.

Description

Technical Field

[0001] This invention belongs to the field of electromagnetic compatibility performance testing technology, and particularly relates to a non-contact electromagnetic compatibility testing device. Background Technology

[0002] Currently, electromagnetic compatibility (EMC) performance testing mainly falls into two categories: contact and non-contact testing methods. Contact testing is the most widely used due to its convenience, flexibility, and simplicity, especially in grassroots testing institutions. However, its drawback is susceptibility to external interference signals. Non-contact EMC testing primarily includes two methods: cable lead-out and fiber optic lead-out. Cable lead-out involves using a dedicated shielded cable to lead the equipment test data from the device under test (DUT) in the testing room to another location where it can be observed, recorded, and read. This method is simple and low-cost, but it easily allows external interference to be introduced into the testing room through the cable, thus affecting the test data. Fiber optic lead-out uses optical fiber to transmit and receive the equipment test data from the DUT in the testing room to another location where it can be observed, recorded, and read. This method offers good shielding, making it difficult for external interference to be introduced into the testing room, and it has virtually no impact on the test data. However, the testing equipment is more complex to operate and more expensive, and only large, specialized testing institutions can afford it.

[0003] Therefore, the defects of the existing technology include: (1) Existing non-contact electromagnetic compatibility testing instruments only have cable and fiber optic leads for testing the electromagnetic compatibility of equipment, and do not achieve non-contact testing through optical scanning. (2) Using non-contact cable leads makes it easy for external interference to be introduced through the cable, affecting the test data. (3) Using non-contact fiber optic leads makes the testing equipment expensive and complicated to operate, and cannot be widely used at the grassroots level. (4) When most existing electromagnetic compatibility performance testing equipment is working, electromagnetic waves can easily cause harm to the staff. (5) Special and confidential electronic equipment requires special testing equipment to complete the testing, and it is difficult for the current testing devices to achieve its functions. (6) It is time-consuming and labor-intensive to transport equipment that is not easy to move to professional testing laboratories and testing institutions, and it is inconvenient for existing electromagnetic compatibility performance testing devices to conduct on-site testing. (7) It is inconvenient to conduct real-time testing of equipment working in special environments using existing testing devices. (8) Existing contact testing devices are prone to introducing external interference and affecting the test data. Summary of the Invention

[0004] To address the problems of existing equipment being susceptible to external interference via cables and the high cost, large size, cumbersome operation, and limited widespread adoption at the grassroots level, this invention provides a non-contact electromagnetic compatibility testing device that intuitively determines and displays the types and parameters of electromagnetic compatibility performance of the device under test, greatly improving the flexibility of the testing device.

[0005] A non-contact electromagnetic compatibility testing device includes a receiving unit placed inside or outside the device under test and a handheld display unit.

[0006] The receiving unit is used to receive electromagnetic interference signals generated by the device under test, and then convert the electromagnetic interference signals into QR code images and display the QR code images in real time. The number of QR code images is the same as the number of interference types contained in the electromagnetic interference signal, and the interference information contained in each QR code image includes: the amplitude change value, frequency change value, and period change value of the interference source.

[0007] The handheld display unit is used to scan each QR code image sequentially. For the optical signal obtained from each scan, it is first converted into a digital electrical signal, then reconstructed based on the digital electrical signal, and then the interference information of the reconstructed QR code image is compared with the interference information pre-stored in the standard code image database. In this way, the QR code image corresponding to the most similar set of interference information is found in the standard code image database, and this QR code image is output and displayed as the standard QR code image corresponding to the currently scanned QR code image, thus completing the electromagnetic compatibility test of the device under test. During the display, the handheld display unit also displays the interference information contained in the standard QR code image.

[0008] Furthermore, the receiving unit includes a signal receiving circuit, a signal sampling circuit, a signal classification circuit, an analog-to-digital conversion circuit, a code pattern forming circuit, a code pattern output display circuit, a first microprocessor, and a first memory; the handheld display unit includes a photoelectric conversion circuit, a code pattern decoding and recovery circuit, a code pattern comparison and selection circuit, a code pattern parameter display circuit, a second microprocessor, a second memory, and a keying circuit.

[0009] The signal receiving circuit is used to receive electromagnetic interference signals generated by the device under test and forward the electromagnetic interference signals to the signal sampling circuit.

[0010] The signal sampling circuit splits the electromagnetic interference signal into two paths: one path is sent to the signal classification circuit, and the other path is sent to the first microprocessor as a start signal.

[0011] The signal classification circuit is used, under the control of the first microprocessor, to compare the frequency, amplitude, and shape of the received electromagnetic interference signal with the standard interference signal pre-stored in the first memory, determine the type of interference signal contained in the received electromagnetic interference signal, and then send the determined standard interference signals to the analog-to-digital conversion circuit.

[0012] The analog-to-digital conversion circuit is used to convert each standard interference signal into a digital standard interference signal under the control of the first microprocessor.

[0013] The code image forming circuit is used to convert each digital standard interference signal into a QR code image signal under the control of the first microprocessor.

[0014] The code image output display circuit is used to display each QR code image signal in graphic form on the screen for scanning by the handheld display unit;

[0015] The photoelectric conversion circuit is used to emit a light beam to scan the QR code on the code output display circuit, complete the acquisition of light signals, and convert the light signals into digital electrical signals;

[0016] The code image decoding and recovery circuit is used to decode the digital electrical signal under the control of the second microprocessor, convert it into readable electrical signal data, and then perform analog-to-digital conversion on the electrical signal data to reconstruct a reconstructed QR code image that can be directly displayed.

[0017] The code image comparison and selection circuit is used, under the control of the second microprocessor, to compare the interference information of the reconstructed QR code image with the interference information in the standard code image database pre-stored in the second memory, thereby finding the QR code image corresponding to the most similar set of interference information in the standard code image database, and using the QR code image as the standard QR code image corresponding to the reconstructed QR code image, while outputting the standard QR code image and its accompanying interference information.

[0018] The code image parameter display circuit is used, under the control of the second microprocessor, to display the standard QR code image output by the code image comparison and selection circuit and its accompanying interference information.

[0019] Furthermore, the signal receiving circuit includes a resonant circuit module, a full-band amplification module, a frequency conversion modulation module, an amplification output module, and a fixed crystal oscillator module. When the signal receiving circuit is working, the electromagnetic interference signal received by the built-in antenna from the device under test first enters the resonant circuit module for harmonic selection, thus purifying the electromagnetic interference signal. The electromagnetic interference signal after harmonic selection enters the full-band amplification module for overall amplitude amplification, and then provides it to the subsequent frequency conversion modulation module. In the frequency conversion modulation module, the amplified electromagnetic interference signal is modulated onto a crystal oscillator signal at a fixed frequency, and then sent to the amplification output module for a second amplification.

[0020] The signal sampling circuit includes a signal coupling module, a signal amplification module, a signal sampling module, and a delay amplification module. The signal coupling module divides the electromagnetic interference signal after secondary amplification from the signal receiving circuit into two paths. One path goes through the signal amplification module and then to the signal sampling module, which sends the sampled electromagnetic interference signal to the first microprocessor as a start signal for interference signal information. The other path goes through the delay amplification module and then to the signal classification circuit.

[0021] The signal classification circuit includes a frequency segmentation module, a signal selection module, and a signal amplification module. The frequency segmentation module receives electromagnetic interference signals from the signal sampling circuit and, under the control of the first microprocessor, classifies the electromagnetic interference signals according to their frequency and interference type, and sends the classified electromagnetic interference signals to the signal selection module. Under the control of the first microprocessor, the signal selection module compares the classified electromagnetic interference signals with standard interference signals pre-stored in the first memory in terms of frequency, amplitude, and shape to determine the interference signal category contained in each classified electromagnetic interference signal, and then sends the determined standard interference signals to the signal amplification module. The signal amplification module amplifies the amplitude of each standard interference signal before sending it to the analog-to-digital conversion circuit.

[0022] The analog-to-digital conversion circuit includes a signal limiting module, a sample-and-hold module, a quantization encoding module, and a code source output module. The signal limiting module controls the received standard interference signal from the signal amplification module within a set amplitude range. Under the control of the first microprocessor, the sample-and-hold module fixes the standard interference signal within the set amplitude range at the required frequency amplitude and inputs the standard interference signal with fixed frequency amplitude into the quantization encoding module in the form of a code stream. Under the control of the first microprocessor, the quantization encoding module encodes the standard interference signal with fixed frequency amplitude. The encoded standard interference signal is then sent to the code pattern forming circuit through the code source output module.

[0023] The code image forming circuit includes a QR code conversion module and a code image forming module. Under the control of the first microprocessor, the QR code conversion module converts the quantized and encoded standard interference signal from the previous stage into a QR code signal and sends the QR code signal to the code image forming module. Under the control of the first microprocessor, the code image forming module automatically and instantly generates the corresponding QR code image based on the QR code signal.

[0024] The code image output display circuit includes an integrated amplification module and a code image display module. Under the control of the first microprocessor, the integrated amplification module performs code image processing and parameter merging on the QR code image from the code image forming module, and sends the obtained code image information to the code image display module for graphic display on the code image display screen, thus completing the work of converting electrical information into optical information.

[0025] The first microprocessor includes an input / output interface module, a CPU chip, and a peripheral circuit module. During operation, through programming, the electromagnetic interference signal output by the signal sampling module enters the CPU chip via the input / output interface module. The CPU chip then generates corresponding control signals based on the electromagnetic interference signal to direct the corresponding circuits to encode, decode, and form a code image, thereby realizing the conversion and display of electrical information to optical information.

[0026] The first memory includes a memory chip and peripheral circuitry; the memory chip is used to store all preset QR code images and corresponding interference information, which are retrieved and used by the signal classification circuit under the control of the first microprocessor.

[0027] Furthermore, the photoelectric conversion circuit includes a light signal acquisition module, a photoelectric conversion module, and a signal amplification module; the light signal acquisition module is used to emit a light beam to scan the QR code on the code output display circuit, complete the acquisition of light signals, and send the acquired light signals to the photoelectric conversion module, which converts the light signals into electrical signals, and finally amplifies the electrical signals through the signal amplification module before outputting them to the code decoding and recovery circuit;

[0028] The code image decoding and recovery circuit module includes a self-test address module, a signal conversion module, and a code image recovery module. Under the control of the second microprocessor, the self-test address module performs address query and information decoding on the electrical signal from the photoelectric conversion circuit. Under the control of the second microprocessor, the signal conversion module performs code image information conversion on the decoded electrical signal, transforming it into the reconstructed QR code image required by the code image comparison and selection circuit. Finally, the reconstructed QR code image is output to the code image comparison and selection circuit through the code image recovery module.

[0029] The code image comparison and selection circuit includes a code image input module, a code image comparison module, and a code image output module. The reconstructed QR code image from the code image decoding and recovery circuit enters the code image comparison module via the code image input module. Under the control of the second microprocessor, the code image comparison module compares the interference information of the reconstructed QR code image with the interference information in the standard code image database pre-stored in the second memory, thereby finding the QR code image corresponding to the closest set of interference information in the standard code image database, and using this QR code image as the standard QR code image corresponding to the reconstructed QR code image. At the same time, the standard QR code image and its accompanying interference information are sent to the code image parameter display circuit through the code image output module.

[0030] The code image parameter display circuit includes a parameter retrieval module, a parameter output module, and a code image parameter display module. Under the control of the second microprocessor, the parameter retrieval module retrieves code image information related to the standard QR code image from the database of the second memory, and inputs the retrieved code image information into the parameter output module for amplification and output. Finally, the amplified code image information is input into the code image parameter display module for display, so that the screen of the code image parameter display module displays the interference information of the corresponding interference signal and the QR code image.

[0031] Furthermore, if the electromagnetic interference signal contains two or more interference signals, the QR code images are displayed periodically on the receiving unit and the handheld display unit. If the electromagnetic interference signal contains only one interference signal, the QR code images are displayed periodically on the receiving unit and the handheld display unit.

[0032] Beneficial effects:

[0033] 1. This invention provides a non-contact electromagnetic compatibility (EMC) testing device, mainly composed of a receiving unit and a handheld display unit. It employs a non-contact optical scanning (electro-optical-graphic) testing method, which reduces the impact of interference signals from related wires on the test data. It can intuitively determine the type of interference source and output relevant interference parameters, making it suitable for applications requiring non-contact EMC testing of equipment. Furthermore, this invention utilizes a handheld optical scanning display unit, avoiding direct contact between the testing personnel and the device under test, reducing harm to the human body. It fills the gap in EMC performance testing where optical signals cannot capture electromagnetic interference signals, thus solving the problem of not being able to test equipment EMC performance using non-contact optical scanning. In addition, both the receiving unit and the handheld display unit of this invention adopt a fully modular design, are small in size, have full functionality, and also have the advantages of simple operation and low cost.

[0034] 2. This invention provides a non-contact electromagnetic compatibility testing device. The receiving unit includes eight modular components: a signal receiving circuit, a signal sampling circuit, a signal classification circuit, an analog-to-digital conversion circuit, a code pattern forming circuit, a code pattern output display circuit, a first microprocessor, and a first memory. The handheld display unit includes seven modular components: a photoelectric conversion circuit, a code pattern decoding and recovery circuit, a code pattern comparison and selection circuit, a code pattern parameter display circuit, and corresponding second microprocessor, second memory, and keying circuit. Therefore, all circuits in this invention adopt an integrated modular design, mounted on two independent circuit boards, achieving a small size, multiple functions, and portability. It is suitable for intuitive electromagnetic compatibility testing in laboratories and on-the-job equipment, and can also be used for on-site testing of large, immovable equipment. It can also be applied to equipment working in other special environments, maximizing the device's working efficiency.

[0035] 3. This invention provides a non-contact electromagnetic compatibility testing device. It utilizes a microprocessor and multiple standard interference source code diagrams pre-stored in memory. Through a calculation control program, it quickly retrieves and compares the corresponding interference code diagrams, so that interference signals and interference information of different types of interference can be displayed alternately on the receiving unit and the handheld display unit. This allows testers to quickly and intuitively see whether the equipment under test is interfered with, what kind of interference source it is, and the specific relevant data of the interference source. Attached Figure Description

[0036] Figure 1 This is a schematic diagram of the non-contact electromagnetic compatibility testing device of the present invention;

[0037] Figure 2This is a schematic block diagram of the electromagnetic compatibility performance code map receiving unit of the present invention;

[0038] Figure 3 This is a schematic diagram of the electromagnetic compatibility performance parameter display unit of the present invention;

[0039] Figure 4 This is a schematic block diagram of the signal receiving circuit of the present invention;

[0040] Figure 5 This is a schematic block diagram of the signal sampling circuit of the present invention;

[0041] Figure 6 This is a schematic diagram of the signal classification circuit of the present invention;

[0042] Figure 7 This is a schematic diagram of the analog-to-digital converter circuit of the present invention;

[0043] Figure 8 This is a schematic block diagram of the code pattern forming circuit of the present invention;

[0044] Figure 9 This is a schematic block diagram of the code output display circuit of the present invention;

[0045] Figure 10 This is a schematic diagram of the first microprocessor circuit of the present invention;

[0046] Figure 11 This is a schematic block diagram of the first memory circuit of the present invention;

[0047] Figure 12 This is a schematic diagram of the photoelectric conversion circuit of the present invention;

[0048] Figure 13 This is a schematic block diagram of the code image decoding and recovery circuit of the present invention;

[0049] Figure 14 This is a schematic block diagram of the code comparison and selection circuit of the present invention;

[0050] Figure 15 This is a schematic block diagram of the code pattern parameter display circuit of the present invention. Detailed Implementation

[0051] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings.

[0052] Electromagnetic compatibility (EMC) refers to the ability of a device or system to operate within its electromagnetic environment without causing unacceptable electromagnetic interference to any other equipment in that environment. Therefore, EMC includes two aspects: firstly, the electromagnetic interference generated by the device during normal operation must not exceed certain limits; secondly, the device must have a certain degree of immunity to electromagnetic interference present in its environment, i.e., electromagnetic susceptibility (EMS).

[0053] To address the issues of existing equipment being susceptible to external interference via cables and the high cost, large size, cumbersome operation, and limited adoption at the grassroots level, this invention provides a circuit for a non-contact electromagnetic compatibility (EMC) performance testing method (optical scanning to pick up electromagnetic interference signals), which is simple to operate, low in cost, and unprecedented in this field. This device is small in size, fully functional, and easy to operate. In particular, it employs a handheld optical scanning testing device, which intuitively identifies and displays the types and parameters of EMC performance of the device under test, greatly improving the flexibility of the testing device and solving the problem that the EMC performance of equipment cannot be tested using non-contact optical scanning.

[0054] Specifically, in the absence of a non-contact electromagnetic compatibility performance testing method (optical scanning to pick up electromagnetic interference signals) circuit in this field, the present invention provides a non-contact electromagnetic compatibility testing device, such as... Figure 1 As shown, it includes a receiving unit placed inside or outside the device under test and a handheld display unit;

[0055] The receiving unit is used to receive electromagnetic interference signals generated by the device under test, and then convert the electromagnetic interference signals into QR code images and display the QR code images in real time. The number of QR code images is the same as the number of interference types contained in the electromagnetic interference signal, and the interference information contained in each QR code image includes: the amplitude change value, frequency change value, and period change value of the interference source.

[0056] The handheld display unit is used to scan each QR code image sequentially. For the optical signal obtained from each scan, it is first converted into a digital electrical signal, then reconstructed based on the digital electrical signal, and then the interference information of the reconstructed QR code image is compared with the interference information pre-stored in the standard code image database. In this way, the QR code image corresponding to the most similar set of interference information is found in the standard code image database, and this QR code image is output and displayed as the standard QR code image corresponding to the currently scanned QR code image, thus completing the electromagnetic compatibility test of the device under test. During the display, the handheld display unit also displays the interference information contained in the standard QR code image.

[0057] Furthermore, such as Figure 2 As shown, the receiving unit includes a signal receiving circuit, a signal sampling circuit, a signal classification circuit, an analog-to-digital conversion circuit, a code pattern forming circuit, a code pattern output and display circuit, a first microprocessor, and a first memory; as shown... Figure 3 As shown, the handheld display unit includes a photoelectric conversion circuit, a code image decoding and recovery circuit, a code image comparison and selection circuit, a code image parameter display circuit, a second microprocessor, a second memory, and a keying circuit. Its basic working principle is as follows: Under normal circumstances, the receiving unit (electro-optical-code) is placed inside or outside the device under test (depending on the need). The signal receiving circuit within the device then processes the acquired electrical signal through a signal sampling circuit, a signal classification circuit, and an analog-to-digital conversion circuit. The electrical signal is then converted into a digital signal and enters the code image forming circuit to achieve electro-optical signal conversion. Finally, the code image output display circuit displays the code image that can be scanned and received by the light beam (if it is interference, one code image is generated periodically; otherwise, multiple code images may be generated and displayed in rotation. The main information contained in the code image includes the amplitude change value, frequency change value, and periodic change value of the interference source). During testing, the handheld display unit scans the aforementioned code image. The scanned optical signal undergoes photoelectric data conversion in the photoelectric conversion circuit, converting the optical signal into an electrical signal, which then enters the code image decoding and recovery circuit. This circuit primarily decodes the code image data and recovers the code image information. Under the control of the first microprocessor, the recovered code image is compared with the standard code pre-stored in the first memory. Figure 1 The signal enters the code image comparison and selection circuit for comparison, selecting the closest interference signal code image. This determines the type of interference source and outputs it to the next stage for visual display. The determined standard code image and data parameters then enter the code image parameter display circuit for alternating code image and data display, achieving the goal of non-contact electromagnetic compatibility performance detection using optical scanning.

[0058] The working principle of each part of the receiving unit circuit is described in detail below.

[0059] The signal receiving circuit is used to receive electromagnetic interference signals generated by the device under test and forward the electromagnetic interference signals to the signal sampling circuit; specifically, as shown in the example... Figure 4 As shown, the entire signal receiving circuit includes a resonant circuit module, a full-band amplification module, a frequency conversion modulation module, an amplification output module, and a fixed crystal oscillator module. During operation, an electromagnetic interference signal received by the built-in antenna first enters the resonant circuit module for harmonic selection, making the received electromagnetic interference signal more complete and pure, facilitating subsequent analog-to-digital conversion. The electromagnetic interference signal, after resonance processing, then enters the next-stage full-band amplification module for overall amplitude amplification, providing it to the subsequent frequency conversion modulation module. In the frequency conversion modulation module, the electromagnetic interference signal is modulated onto a fixed-frequency crystal oscillator signal, and then sent to the next-stage amplification output module for a second amplification, providing a sufficiently large signal to subsequent circuits. Therefore, the signal receiving circuit is designed to receive, amplify, and process electronic interference signals to obtain the electromagnetic compatibility performance parameters of electronic equipment. It performs amplitude and frequency limiting preprocessing on signals from electronic equipment containing various interference signals, provides sampling signals to the first microprocessor circuit, and outputs the sampling signals required by subsequent circuits.

[0060] The signal sampling circuit splits the electromagnetic interference signal into two paths: one path is sent to the signal classification circuit, and the other path is sent to the first microprocessor as a start signal; specifically, as shown in... Figure 5 As shown, the signal sampling circuit includes a signal coupling module, a signal amplification module, a signal sampling module, and a delay amplification module. The signal coupling module splits the secondary amplified electromagnetic interference signal from the signal receiving circuit into two paths. One path passes through the signal amplification module and then reaches the signal sampling module, where the sampled electromagnetic interference signal is sent to the first microprocessor as a start signal for interference signal information. The other path passes through the delay amplification module and then goes to the signal classification circuit. Therefore, the signal sampling circuit transforms the signal output from the receiving circuit into a sampled signal recognizable by the first microprocessor and a digital signal that can be classified, then sends them in two separate paths to the first microprocessor circuit and the signal classification circuit, respectively.

[0061] The signal classification circuit, under the control of the first microprocessor, compares the received electromagnetic interference signal with standard interference signals pre-stored in the first memory in terms of frequency, amplitude, and shape to determine the type of interference signal contained in the received electromagnetic interference signal. Then, it sends the determined standard interference signals to the analog-to-digital conversion circuit; specifically, as shown... Figure 6As shown, the signal classification circuit includes a frequency segmentation module, a signal selection module, and a signal amplification module. The frequency segmentation module receives electromagnetic interference signals from the signal sampling circuit and, under the control of the first microprocessor, classifies the electromagnetic interference signals according to their frequency and interference type, such as high-frequency Type I interference signals, mid-frequency Type II interference signals, and low-frequency Type III interference signals. The classified electromagnetic interference signals are then sent to the signal selection module. Under the control of the first microprocessor, the signal selection module compares the classified electromagnetic interference signals with standard interference signals pre-stored in the first memory in terms of frequency, amplitude, and shape to determine the interference signal category contained in each classified electromagnetic interference signal. The determined standard interference signals are then sent to the signal amplification module. The signal amplification module amplifies the amplitude of each standard interference signal before sending it to the analog-to-digital conversion circuit. In other words, the signal classification circuit, under the control of the first microprocessor, compares the received interference signals according to the interference signal types pre-stored in the first memory in terms of frequency, amplitude, and shape to determine the category of the received interference signal, facilitating the next step of analog-to-digital conversion.

[0062] The analog-to-digital conversion circuit, under the control of the first microprocessor, converts each standard interference signal into a digital standard interference signal; specifically, as shown in the example... Figure 7 As shown, the analog-to-digital converter (ADC) circuit includes a signal limiting module, a sample-and-hold module, a quantization encoding module, and a code source output module. The signal limiting module controls the received standard interference signal from the signal amplification module within a set amplitude range. Under the control of the first microprocessor, the sample-and-hold module fixes the standard interference signal within the set amplitude range at the required frequency amplitude and inputs the frequency-amplitude-fixed standard interference signal into the quantization encoding module as a code stream. Under the control of the first microprocessor, the quantization encoding module encodes the frequency-amplitude-fixed standard interference signal. The encoded standard interference signal is then sent to the code pattern forming circuit through the code source output module. In other words, the analog-to-digital converter (ADC) circuit converts the received interference signal from analog to digital to obtain the digital signal required by subsequent circuits. Under the control of the first microprocessor circuit, the ADC circuit automatically performs the conversion based on the interference signal.

[0063] The code image forming circuit, under the control of the first microprocessor, converts each digital standard interference signal into a QR code image signal; specifically, as shown... Figure 8As shown, the code image forming circuit includes a QR code conversion module and a code image forming module. Under the control of the first microprocessor, the QR code conversion module converts the quantized and encoded standard interference signal from the preceding stage into a QR code signal and sends the QR code signal to the code image forming module. Under the control of the first microprocessor, the code image forming module automatically and instantly generates the corresponding QR code image based on the QR code signal. Therefore, the code image forming circuit automatically converts the digital signal from the preceding stage circuit into a QR code image signal under the control of the first microprocessor for use by subsequent circuits.

[0064] The code image output display circuit is used to display each QR code signal in graphic form on the screen for scanning by the handheld display unit; specifically, as shown in the example... Figure 9 As shown, the code image output display circuit includes an integrated amplification module and a code image display module. Under the control of the first microprocessor, the integrated amplification module processes and merges the QR code image from the code image forming module, and sends the resulting code image information to the code image display module for graphic display on the code image display screen. This completes the conversion of electrical information into optical information, achieving the purpose of picking up electrical signals through optical signals. Therefore, the code image output display circuit is designed to display interfering code image signals from the previous stage in graphic form on the screen for graphic scanning, achieving the purpose of picking up electrical signals through optical signals.

[0065] like Figure 10 As shown, the first microprocessor includes an input / output interface module, a CPU chip, and peripheral circuit modules. This constitutes a complete, minimal system composed of a single-chip microcomputer control system and its peripheral circuits. During operation, through programming, the electromagnetic interference signal output by the signal sampling module enters the CPU control chip circuit via the input / output interface module. The CPU chip processes the sampled signal using the pre-edited program, and the result is used to output corresponding control signals to direct the corresponding circuits for encoding, decoding, and code pattern formation, thus completing the action selection for the entire device circuit and ultimately achieving the goal of converting electrical information into optical information and displaying it on the screen. It should be noted that the first microprocessor requires a specific program to complete its work and is the core component of the entire device. The program is simple to write and can be easily modified according to actual needs. Therefore, the first microprocessor is the system control circuit set up for the device, providing data, control, storage, and other operations for the entire device.

[0066] like Figure 11As shown, the first memory includes a memory chip and peripheral circuitry. Under normal circumstances, the memory chip stores all preset QR code images and corresponding interference information. During operation, it is retrieved by the signal classification circuit under the control of the first microprocessor. Therefore, the first memory is a dedicated memory for the device, providing all data, standard interference code images, etc., for the entire device.

[0067] The working principle of each part of the handheld display unit circuit is explained in detail below.

[0068] The photoelectric conversion circuit is used to emit a light beam to scan the QR code image on the code image output display circuit, completing the acquisition of the light signal and converting the light signal into a digital electrical signal; specifically, such as Figure 12 As shown, the photoelectric conversion circuit includes a light signal acquisition module, a photoelectric conversion module, and a signal amplification module. The light signal acquisition module emits a light beam to scan the QR code on the code output display circuit, completing the acquisition of the light signal. The acquired light signal is then sent to the photoelectric conversion module, which converts the light signal into an electrical signal. Finally, the signal amplification module amplifies the electrical signal before outputting it to the code decoding and recovery circuit. In other words, the photoelectric conversion circuit is a circuit designed to convert the scanned light signal into the required electrical signal under the control of a second microprocessor.

[0069] The code image decoding and recovery circuit, under the control of the second microprocessor, decodes the digital electrical signal, converts it into readable electrical signal data, and then performs analog-to-digital conversion on the electrical signal data to reconstruct a reconstructed QR code image that can be directly displayed; specifically, as shown... Figure 13 As shown, the code image decoding and recovery circuit module includes a self-test address module, a signal conversion module, and a code image recovery module. Under the control of the second microprocessor, the self-test address module performs address lookup and information decoding on the electrical signal from the photoelectric conversion circuit. Under the control of the second microprocessor, the signal conversion module converts the decoded electrical signal into code image information, transforming it into the reconstructed QR code image required by the code image comparison and selection circuit. Finally, the code image recovery module outputs the reconstructed QR code image to the code image comparison and selection circuit. In other words, the code image decoding and recovery circuit decodes the converted digital electrical signal under the control of the second microprocessor, converting it into readable electrical signal data, and then performs analog-to-digital conversion on this data to restore the code image signal parameters that can be directly displayed.

[0070] The code image comparison and selection circuit, under the control of the second microprocessor, compares the interference information of the reconstructed QR code image with the interference information pre-stored in the standard code image database in the second memory. It then searches the standard code image database for the QR code image corresponding to the closest set of interference information and uses this QR code image as the standard QR code image corresponding to the reconstructed QR code image. Simultaneously, it outputs the standard QR code image and its associated interference information. Specifically, as follows... Figure 14 As shown, the code image comparison and selection circuit includes a code image input module, a code image comparison module, and a code image output module. The reconstructed QR code image from the code image decoding and recovery circuit enters the code image comparison module via the code image input module. Under the control of the second microprocessor, the code image comparison module compares the interference information of the reconstructed QR code image with the interference information in the standard code image database pre-stored in the second memory. It then finds the QR code image corresponding to the closest set of interference information in the standard code image database and uses this QR code image as the standard QR code image corresponding to the reconstructed QR code image. Simultaneously, the standard QR code image and its associated interference information are sent to the code image parameter display circuit via the code image output module. Therefore, the code image comparison and selection circuit, under the control of the second microprocessor, compares the interference code image signal from the previous stage with the standard interference code image signal pre-stored in the second memory, selects the closest interference signal code image, and outputs it to the next stage circuit.

[0071] The code image parameter display circuit, under the control of the second microprocessor, displays the standard QR code image output by the code image comparison and selection circuit and its accompanying interference information; specifically, such as... Figure 15 As shown, the code image parameter display circuit includes a parameter retrieval module, a parameter output module, and a code image parameter display module. Under the control of the second microprocessor, the parameter retrieval module retrieves code image information related to the standard QR code image from the database of the second memory, and inputs the retrieved code image information into the parameter output module for amplification and output. Finally, the amplified code image information is input into the code image parameter display module for display, so that the screen of the code image parameter display module displays the interference information of the corresponding interference signal and the QR code image. In other words, the code image parameter display circuit is designed to visually display the interference code image information from the previous stage in the form of code image display and data parameter rotation on the screen, ultimately achieving the purpose of picking up electrical signals through optical signals.

[0072] The following is a summary of how to use optical scanning to complete the electromagnetic compatibility testing process for non-contact electromagnetic compatibility testing devices on-site:

[0073] When the non-contact optical scanning detection device is working normally, the electromagnetic compatibility performance code image receiving unit (electro-optical-code) circuit is placed inside or outside the device under test (DUT) (depending on the needs). With the power on, the signal receiving circuit inside the device receives the electromagnetic interference signals generated by the DUT instantly through the antenna. The received interference electrical signals (signals from numerous different periodic interference sources) are converted into digital signals by the signal sampling circuit, signal classification circuit, and analog-to-digital conversion circuit within the device. These digital signals then enter the code image forming circuit to achieve electro-optical signal conversion. Finally, the code image output display circuit displays a QR code image that can be received by the beam scan (if it is a single type of interference, one code image is generated periodically; otherwise, multiple code images may be generated and displayed in rotation. The main information contained in the code image includes the amplitude variation value, frequency variation value, and period variation value of the interference source). During testing, the handheld electromagnetic compatibility performance parameter display unit circuit is used. By pressing the scan key in the key control circuit, the light beam emitted by the testing device can directly scan the QR code image containing various information. The scanned light signal undergoes optical-to-electrical data conversion in the photoelectric conversion module, converting the light signal into a digital electrical signal and entering the code image decoding and recovery circuit. This circuit mainly completes the data graphic decoding of the code image and restores it to the original code image (the code image contains the amplitude change value, frequency change value, period change value, etc. of the interference source). The recovered code image, under the control of the second microprocessor, is compared with a standard code image pre-stored in the second memory (the code image stored in the memory also includes amplitude variation values, frequency variation values, period variation values, etc., and its types of interference sources form the most comprehensive database of various interference source code images based on the classification of interference sources. In this database, any currently discovered interference source can be retrieved for comparison under the control of the microprocessor). In this circuit, the second microprocessor searches for the closest set of data in the first memory based on the code image data from the previous stage, retrieves the corresponding code image (this code image represents the type of interference source and displays relevant data), and outputs it to the next stage for visual display. Finally, the handheld electromagnetic compatibility performance parameter display unit displays alternating interference source code diagrams and data display screens (for example, if the interference source detected is due to arc discharge interference generated by a mechanical switch in the device under test, then the displayed code diagram is a standard arc discharge interference diagram, and the related data displayed in rotation is the interference source data received by the receiving antenna). This achieves the goal of quickly and intuitively seeing whether the device under test has interference, what kind of interference source it is, and what the relevant data of the interference source is through optical scanning.

[0074] Therefore, this invention addresses the following issues: 1. Blocking the influence of interference signals introduced by connecting wires on the test data. 2. The large size, inconvenience of carrying, complex operation, and high cost of the testing device, hindering its widespread use at the grassroots level. 3. Avoiding direct contact between testing personnel and the device under test, reducing harm to the human body. 4. Achieving corresponding testing for devices that are not easily moved. This invention proposes an alternative form of non-contact electromagnetic compatibility (EMC) testing device: testing the EMC performance of the device through optical scanning. Specifically, the non-contact EMC testing device uses a photo-to-electric conversion method, utilizing a CPU system control circuit and multiple standard interference source code diagrams pre-stored in memory. Through a calculation control program, it quickly retrieves and compares the corresponding interference code diagrams. During testing, it receives, transforms, generates, picks up, and displays the interference signal source, intuitively showing the type of interference signal and corresponding data. This addresses the shortcomings of existing non-contact EMC testing instruments and solves the problem of not being able to directly test the EMC of equipment using optical scanning.

[0075] In summary, this invention addresses the problems of existing non-contact electromagnetic compatibility (EMC) testing instruments. Existing non-contact EMC testing instruments using cables are prone to external interference, affecting test data. Fiber optic cables result in expensive and complex testing devices, hindering widespread use at the grassroots level. Conventional contact methods for EMC testing can cause electromagnetic harm to workers and introduce external interference. Technically, this invention introduces a novel optical scanning non-contact testing method, utilizing a CPU system control circuit and a pre-stored EMC source code database to effectively solve these problems. The receiving unit includes: a signal receiving circuit, a signal sampling circuit, a signal classification circuit, an analog-to-digital conversion circuit, a code image forming circuit, a code image output and display circuit, a first microprocessor circuit, and a first memory. The handheld display unit includes: a photoelectric conversion circuit, a code image decoding and recovery circuit, a code image comparison and selection circuit, a code image parameter display circuit, and corresponding second microprocessor, second memory, and keying circuit. This achieves full modularity of the device, resulting in a small size, multiple functions, and portability, making it suitable for intuitive electromagnetic compatibility testing of equipment in laboratories and during operation. Furthermore, this non-contact electromagnetic compatibility testing device can intuitively read the interference source type and related data of the equipment under test using optical scanning, and can also perform on-site testing of large, immobile equipment. It can also be used with equipment operating in other special environments, maximizing the device's working efficiency.

[0076] Of course, the present invention may have other various embodiments. Without departing from the spirit and essence of the present invention, those skilled in the art can make various corresponding changes and modifications according to the present invention, but these corresponding changes and modifications should all fall within the protection scope of the appended claims.

Claims

1. A non-contact electromagnetic compatibility testing device, characterized in that, This includes a receiving unit placed inside or outside the device under test, as well as a handheld display unit; The receiving unit is used to receive electromagnetic interference signals generated by the device under test, and then convert the electromagnetic interference signals into QR code images and display the QR code images in real time. The number of QR code images is the same as the number of interference types contained in the electromagnetic interference signal, and the interference information contained in each QR code image includes: the amplitude change value, frequency change value, and period change value of the interference source. The handheld display unit is used to scan each QR code image sequentially. For the optical signal obtained from each scan, it is first converted into a digital electrical signal, then reconstructed based on the digital electrical signal, and then the interference information of the reconstructed QR code image is compared with the interference information pre-stored in the standard code image database. In this way, the QR code image corresponding to the most similar set of interference information is found in the standard code image database, and this QR code image is output and displayed as the standard QR code image corresponding to the currently scanned QR code image, thus completing the electromagnetic compatibility test of the device under test. When the handheld display unit displays, it also displays the interference information contained in the standard QR code image. The receiving unit includes a signal receiving circuit, a signal sampling circuit, a signal classification circuit, an analog-to-digital conversion circuit, a code pattern forming circuit, a code pattern output display circuit, a first microprocessor, and a first memory; the handheld display unit includes a photoelectric conversion circuit, a code pattern decoding and recovery circuit, a code pattern comparison and selection circuit, a code pattern parameter display circuit, a second microprocessor, a second memory, and a keying circuit. The signal receiving circuit is used to receive electromagnetic interference signals generated by the device under test and forward the electromagnetic interference signals to the signal sampling circuit. The signal sampling circuit splits the electromagnetic interference signal into two paths: one path is sent to the signal classification circuit, and the other path is sent to the first microprocessor as a start signal. The signal classification circuit is used, under the control of the first microprocessor, to compare the frequency, amplitude, and shape of the received electromagnetic interference signal with the standard interference signal pre-stored in the first memory, determine the type of interference signal contained in the received electromagnetic interference signal, and then send the determined standard interference signals to the analog-to-digital conversion circuit. The analog-to-digital conversion circuit is used to convert each standard interference signal into a digital standard interference signal under the control of the first microprocessor. The code image forming circuit is used to convert each digital standard interference signal into a QR code image signal under the control of the first microprocessor. The code image output display circuit is used to display each QR code image signal in graphic form on the screen for scanning by the handheld display unit; The photoelectric conversion circuit is used to emit a light beam to scan the QR code on the code output display circuit, complete the acquisition of light signals, and convert the light signals into digital electrical signals; The code image decoding and recovery circuit is used to decode the digital electrical signal under the control of the second microprocessor, convert it into readable electrical signal data, and then perform analog-to-digital conversion on the electrical signal data to reconstruct a reconstructed QR code image that can be directly displayed. The code image comparison and selection circuit is used, under the control of the second microprocessor, to compare the interference information of the reconstructed QR code image with the interference information in the standard code image database pre-stored in the second memory, thereby finding the QR code image corresponding to the most similar set of interference information in the standard code image database, and using the QR code image as the standard QR code image corresponding to the reconstructed QR code image, while outputting the standard QR code image and its accompanying interference information. The code image parameter display circuit is used, under the control of the second microprocessor, to display the standard QR code image output by the code image comparison and selection circuit and its accompanying interference information.

2. The non-contact electromagnetic compatibility testing device as described in claim 1, characterized in that, The signal receiving circuit includes a resonant circuit module, a full-band amplification module, a frequency conversion modulation module, an amplification output module, and a fixed crystal oscillator module. When the signal receiving circuit is working, the electromagnetic interference signal received by the built-in antenna from the device under test first enters the resonant circuit module for harmonic selection, thus purifying the electromagnetic interference signal. The electromagnetic interference signal after harmonic selection enters the full-band amplification module for overall amplitude amplification, and then is provided to the subsequent frequency conversion modulation module. In the frequency conversion modulation module, the amplified electromagnetic interference signal is modulated onto a crystal oscillator signal at a fixed frequency, and then sent to the amplification output module for a second amplification. The signal sampling circuit includes a signal coupling module, a signal amplification module, a signal sampling module, and a delay amplification module. The signal coupling module divides the electromagnetic interference signal after secondary amplification from the signal receiving circuit into two paths. One path goes through the signal amplification module and then to the signal sampling module, which sends the sampled electromagnetic interference signal to the first microprocessor as a start signal for interference signal information. The other path goes through the delay amplification module and then to the signal classification circuit. The signal classification circuit includes a frequency segmentation module, a signal selection module, and a signal amplification module. The frequency segmentation module receives electromagnetic interference signals from the signal sampling circuit and, under the control of the first microprocessor, classifies the electromagnetic interference signals according to their frequency and interference type, and sends the classified electromagnetic interference signals to the signal selection module. Under the control of the first microprocessor, the signal selection module compares the classified electromagnetic interference signals with standard interference signals pre-stored in the first memory in terms of frequency, amplitude, and shape to determine the interference signal category contained in each classified electromagnetic interference signal, and then sends the determined standard interference signals to the signal amplification module. The signal amplification module amplifies the amplitude of each standard interference signal before sending it to the analog-to-digital conversion circuit. The analog-to-digital conversion circuit includes a signal limiting module, a sample-and-hold module, a quantization encoding module, and a code source output module. The signal limiting module controls the received standard interference signal from the signal amplification module within a set amplitude range. Under the control of the first microprocessor, the sample-and-hold module fixes the standard interference signal within the set amplitude range at the required frequency amplitude and inputs the standard interference signal with fixed frequency amplitude into the quantization encoding module in the form of a code stream. Under the control of the first microprocessor, the quantization encoding module encodes the standard interference signal with fixed frequency amplitude. The encoded standard interference signal is then sent to the code pattern forming circuit through the code source output module. The code image forming circuit includes a QR code conversion module and a code image forming module. Under the control of the first microprocessor, the QR code conversion module converts the quantized and encoded standard interference signal from the previous stage into a QR code signal and sends the QR code signal to the code image forming module. Under the control of the first microprocessor, the code image forming module automatically and instantly generates the corresponding QR code image based on the QR code signal. The code image output display circuit includes an integrated amplification module and a code image display module. Under the control of the first microprocessor, the integrated amplification module organizes and merges the QR code images from the code image forming module in real time, and sends the obtained code image information to the code image display module for graphic display on the code image display screen, thus completing the work of converting electrical information into optical information. The first microprocessor includes an input / output interface module, a CPU chip, and a peripheral circuit module. During operation, through programming, the electromagnetic interference signal output by the signal sampling module enters the CPU chip via the input / output interface module. The CPU chip then generates corresponding control signals based on the electromagnetic interference signal to direct the corresponding circuits to encode, decode, and form a code image, thereby realizing the conversion and display of electrical information to optical information. The first memory includes a memory chip and peripheral circuitry; the memory chip is used to store all preset QR code images and corresponding interference information, which are retrieved and used by the signal classification circuit under the control of the first microprocessor.

3. The non-contact electromagnetic compatibility testing device as described in claim 1, characterized in that, The photoelectric conversion circuit includes a light signal acquisition module, a photoelectric conversion module, and a signal amplification module. The light signal acquisition module is used to emit a light beam to scan the QR code on the code output display circuit in real time, complete the acquisition of light signals, and send the acquired light signals to the photoelectric conversion module, which converts the light signals into electrical signals. Finally, the electrical signals are amplified by the signal amplification module and output to the code decoding and recovery circuit. The code image decoding and recovery circuit includes a self-test address module, a signal conversion module, and a code image recovery module. Under the control of the second microprocessor, the self-test address module performs real-time address query and information decoding of the electrical signal from the photoelectric conversion circuit. Under the control of the second microprocessor, the signal conversion module converts the decoded electrical signal real-time code image information into the reconstructed QR code image required by the code image comparison and selection circuit. Finally, the reconstructed QR code image is output to the code image comparison and selection circuit through the code image recovery module. The code image comparison and selection circuit includes a code image input module, a code image comparison module, and a code image output module. The reconstructed QR code image from the code image decoding and recovery circuit enters the code image comparison module via the code image input module. Under the control of the second microprocessor, the code image comparison module compares the interference information of the reconstructed QR code image with the interference information in the standard code image database pre-stored in the second memory, thereby finding the QR code image corresponding to the closest set of interference information in the standard code image database, and using this QR code image as the standard QR code image corresponding to the reconstructed QR code image. At the same time, the standard QR code image and its accompanying interference information are sent to the code image parameter display circuit through the code image output module. The code image parameter display circuit includes a parameter retrieval module, a parameter output module, and a code image parameter display module. Under the control of the second microprocessor, the parameter retrieval module retrieves code image information related to the standard QR code image from the database of the second memory, and inputs the retrieved code image information into the parameter output module for amplification and output. Finally, the amplified code image information is input into the code image parameter display module for display, so that the screen of the code image parameter display module displays the interference information of the corresponding interference signal and the QR code image.

4. A non-contact electromagnetic compatibility testing device as described in any one of claims 1 to 3, characterized in that, If the electromagnetic interference signal contains two or more interference signals, the QR code images will be displayed periodically on the receiving unit and the handheld display unit. If the electromagnetic interference signal contains only one interference signal, the QR code images will be displayed periodically on the receiving unit and the handheld display unit.

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