Test circuit and test system
By designing a test circuit including main control module, processing module and conversion module, the accuracy and efficiency problems of manual testing of the small signal amplification circuit board of the mass spectrometer are solved, and automated, fast and accurate test results are achieved.
Patent Information
- Application Number
- CN202411866152.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-18
- Publication Date
- 2025-02-14
AI Technical Summary
The small signal amplification circuit board of manual test mass spectrometer has problems such as poor accuracy of measurement results and low testing efficiency.
Design a test circuit, including a main control module, a processing module and a conversion module, the main control module outputs a test signal with a set frequency, the processing module processes the test signal and inputs it to the circuit board to be tested, and the conversion module converts the differential signal into Single-ended signal, and the actual frequency is detected by the main control module to compare the test results.
Through automated processing, the dependence on technicians is reduced, the testing efficiency and accuracy are improved, and the test results can be obtained quickly and accurately.
Smart Images
Figure CN119438872A_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the technical field of electronic circuits, and in particular to a test circuit and a test system. Background Art
[0002] The current circuit board technology is changing with each passing day, and the corresponding circuit board testing technology is also constantly improving. Circuit board testing technology generally measures voltage, current, waveform, power, etc. That is, the excitation source outputs the test signal to the circuit board to be tested, and the circuit board outputs the result signal to the oscilloscope, and then manually observes whether the output result signal meets the standard, so as to judge whether the circuit board is qualified or not.
[0003] For the small signal amplifier circuit board of the mass spectrometer, manual observation of the result signal output by the signal amplifier circuit board will heavily rely on the experience and ability of the technicians, thus affecting the accuracy of the judgment result; at the same time, the manual judgment process is slow and cannot adapt to the high-efficiency production efficiency of the mass spectrometer. Summary of the invention
[0004] In view of this, the embodiments of the present application provide a test circuit and a test system, which can effectively solve the problems of poor measurement accuracy and low test efficiency caused by manually testing the small signal amplifier circuit board of the mass spectrometer.
[0005] In a first aspect, an embodiment of the present application provides a test circuit, including a main control module, a processing module and a conversion module;
[0006] The main control module is used to output a test signal of a set frequency;
[0007] The input end of the processing module is connected to the first output end of the main control module, and the processing module is used to process the test signal and then input it to the input end of the circuit board to be tested;
[0008] The input end of the conversion module is used to connect to the output end of the circuit board to be tested, and the conversion module is used to convert the differential signal output by the circuit board to obtain a single-ended signal;
[0009] The main control module is also used to detect the actual frequency of the single-ended signal, and compare the actual frequency with the set frequency of the test signal to obtain a test result.
[0010] In some embodiments, the test circuit further includes an indication module;
[0011] The input end of the indication module is connected to the second output end of the main control module; the indication module is used to receive the test result and indicate the test result.
[0012] In some embodiments, the test circuit further includes a buffer module;
[0013] The input end of the buffer module is the output end of the conversion module, the output end of the buffer module is connected to the input end of the main control module, and the buffer module performs buffering processing on the single-ended signal and then inputs it into the main control module.
[0014] In some embodiments, the processing module includes an amplification unit and a filtering unit;
[0015] The input end of the amplifying unit is connected to the first output end of the main control module, and the amplifying unit is used to amplify the test signal to match the circuit board to be tested;
[0016] The input end of the filtering unit is connected to the output end of the amplifying unit, and the output end of the filtering unit is connected to the input end of the circuit board to be tested; the filtering unit is used to filter the test signal after amplification and output it to the circuit board to be tested after filtering.
[0017] In some embodiments, the filtering unit includes a first filter, a second filter, and a buffer;
[0018] The input end of the first filter is connected to the output end of the amplifying unit, the output end of the first filter is connected to the input end of the second filter, the output end of the second filter is connected to the input end of the buffer, and the output end of the buffer is used to connect to the input end of the circuit board to be tested;
[0019] The amplified test signal is input to the buffer after being filtered by the first filter and the second filter, and the buffer further performs buffer processing on the filtered test signal and outputs it to the circuit board to be tested.
[0020] In some embodiments, the filtering unit further includes a feedback resistor; a first end of the feedback resistor is connected to an output end of the buffer, and a second end of the feedback resistor is connected to an input end of the second filter.
[0021] In some embodiments, the conversion module includes at least one group of conversion units; the two input ends of each group of the conversion units are connected to the output end of the circuit board under test, and the conversion unit is used to convert the differential signal output by the circuit board under test and then output the single-ended signal.
[0022] In some embodiments, the indication module includes a display unit and / or a sound unit;
[0023] The display unit includes an LED light or an electronic display screen; different display modes of the LED light correspond to different test results; the electronic display screen displays the test results in a preset manner;
[0024] The sound unit includes a speaker for playing a preset sound signal.
[0025] In some embodiments, the main control module includes an FPGA, and the FPGA outputs the test signal in a frequency sweep form.
[0026] In a fourth aspect, an embodiment of the present application provides a test system, comprising the above-mentioned test circuit and a circuit board to be tested.
[0027] The embodiments of the present application have the following beneficial effects:
[0028] The main control module of the test circuit of the present application actively outputs a test signal, and performs frequency processing on the test signal and the single-ended signal obtained by output processing of the circuit board to be tested. The automated processing of the main control module reduces the test process's dependence on manual labor by technicians, and the automated processing of the main control module is fast and efficient, which can further improve the detection efficiency and accuracy of the circuit board to be tested. BRIEF DESCRIPTION OF THE DRAWINGS
[0029] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.
[0030] Figure 1 A schematic diagram of the principle structure of a test circuit in an embodiment of the present application is shown;
[0031] Figure 2 A circuit diagram of a processing module in an embodiment of the present application is shown;
[0032] Figure 3 A circuit diagram of a conversion module in an embodiment of the present application is shown;
[0033] Figure 4 A circuit diagram of an indication module in an embodiment of the present application is shown.
[0034] Description of main component symbols:
[0035] 10-main control module; 20-processing module; 21-amplification unit; 22-filtering unit; 30-conversion module; 40-buffer module; 50-indication module. DETAILED DESCRIPTION
[0036] The technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments.
[0037] The components of the embodiments of the present application generally described and shown in the drawings herein may be arranged and designed in various configurations. Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the application claimed for protection, but merely represents the selected embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without making creative work belong to the scope of protection of the present application.
[0038] Hereinafter, the terms "including", "having" and their cognates that can be used in various embodiments of the present application are intended only to indicate specific features, numbers, steps, operations, elements, components or a combination of the foregoing items, and should not be understood as first excluding the existence of one or more other features, numbers, steps, operations, elements, components or a combination of the foregoing items or increasing the possibility of one or more features, numbers, steps, operations, elements, components or a combination of the foregoing items. In addition, the terms "first", "second", "third" and the like are only used to distinguish descriptions and cannot be understood as indicating or implying relative importance.
[0039] Unless otherwise defined, all terms (including technical terms and scientific terms) used herein have the same meanings as those generally understood by those skilled in the art to which the various embodiments of the present application belong. The terms (such as those defined in generally used dictionaries) will be interpreted as having the same meanings as the contextual meanings in the relevant technical field and will not be interpreted as having idealized meanings or overly formal meanings unless clearly defined in the various embodiments of the present application.
[0040] In conjunction with the accompanying drawings, some embodiments of the present application are described in detail below. In the absence of conflict, the following embodiments and features in the embodiments can be combined with each other.
[0041] When performing functional testing on the small signal amplifier circuit board of a mass spectrometer, manual operation is complicated, the parameters of the excitation source that generates the test signal need to be set manually, and the adjustment of the parameters takes a long time. The present application proposes an intelligent and automated test circuit to improve the test production efficiency, and by processing the output signal of the small signal amplifier circuit board, the noise level interference on the judgment of the test result is reduced, thereby further improving the reliability of the test result.
[0042] The test circuit is described below in conjunction with some specific embodiments.
[0043] Figure 1 A schematic diagram of a principle structure of a test circuit of an embodiment of the present application is shown. Exemplarily, the test circuit includes a main control module 10, a processing module 20, a conversion module 30, a buffer module 40 and an indication module 50.
[0044] The input end of the processing module 20 is connected to the first output end of the main control module 10, and the output end of the processing module 20 is used to connect to the input end of the circuit board to be tested; the processing module 20 processes the test signal and inputs it to the input end of the circuit board to be tested; the circuit board to be tested is a small signal amplification circuit board of the mass spectrometer, and of course it can also be a signal amplifier board of other instruments. Different circuit boards to be tested have different set frequencies of the test signal and / or waveforms of the test signal.
[0045] The input end of the conversion module 30 is used to connect to the output end of the circuit board to be tested, the output end of the conversion module 30 is used to connect to the input end of the buffer module 40, the output end of the buffer module 40 is connected to the output end of the main control module 10, and the second output end of the main control module 10 is connected to the indication module 50; the conversion module 30 converts the differential signal output by the circuit board to be tested to obtain a single-ended signal, and the single-ended signal is input to the main control module 10 after buffering by the buffer module 40, and the main control module 10 detects the actual frequency of the single-ended signal, and compares the actual frequency with the set frequency of the test signal to obtain the test result; the test result is input into the indication module, so that the indication module can intuitively indicate the test result.
[0046] In the test circuit of the present application, the main control module actively sends out a test signal of a set frequency. After the test signal is processed and input into the circuit board to be tested, a differential signal will be output. The differential signal is then converted and processed, and the actual frequency of the feedback is detected by the main control module. The actual frequency is compared with the set frequency to obtain the test result quickly and accurately, and the test result can be intuitively indicated through the indication module.
[0047] In this embodiment, the main control module uses FPGA, and FPGA simulates the input signal of the small signal amplification circuit board. FPGA outputs a square wave signal with a duty cycle of 50% and a set frequency of 1kHz-10kHz as a test signal. The test signal is output in the form of frequency sweeping. The signal amplitude of the test signal is 3.3V. Frequency sweeping refers to the process in which the frequency of a signal changes continuously from high to low (or from low to high) within a frequency band. It is often used in electronic measurements to measure the impedance characteristics and transmission characteristics of the network. For example, after outputting a 1kHz signal for 1S, it switches to outputting a 2kHz signal for 1S, and so on. The setting frequency of the test signal is not limited to one, but from low to high. The frequency detection is comprehensive, which effectively reduces the actual failure rate of the circuit board.
[0048] In this embodiment, the processing module 20 includes an amplifying unit 21 and a filtering unit 22; the input end of the amplifying unit 21 is connected to the first output end of the main control module 10, and the amplifying unit 21 amplifies the test signal to match the circuit board to be tested; the input end of the filtering unit 22 is connected to the output end of the amplifying unit 21, and the output end of the filtering unit 22 is connected to the input end of the circuit board to be tested, and the amplified test signal is filtered to filter out unnecessary frequency parts in the signal, and is output to the circuit board to be tested after filtering.
[0049] In this embodiment, Figure 2 As shown, the amplification unit 21 includes a first operational amplifier U1, a first resistor R1, a second resistor R2 and a third resistor R3; the first end of the first resistor R1 is grounded, and the second end of the first resistor R1 is connected to the in-phase input end of the first operational amplifier U1; the first end of the third resistor R1 is connected to the output end of the main control module 10, and the second end of the third resistor R1 is connected to the inverting input end of the first operational amplifier U1; the first end of the third resistor R3 is connected to the inverting input end of the first operational amplifier U1, and the second end of the third resistor R3 is connected to the output end of the first operational amplifier U1. The second resistor R2, the third resistor R3 and the first operational amplifier U1 constitute a reverse amplifier, which reversely amplifies the 3.3V test signal received by the first operational amplifier U1. After reverse amplification, the amplitude of the test signal becomes -200mV, and the frequency remains unchanged to match the input requirements of the circuit to be tested. As another implementation method, a MOS tube can also be used to control a constant voltage source to output a square wave test signal.
[0050] In this embodiment, Figure 2 As shown, the filtering unit 22 includes a first filter, a second filter, a buffer and a feedback resistor R7; the input end of the first filter is connected to the output end of the amplification unit 21, the output end of the first filter is connected to the input end of the second filter, the output end of the second filter is connected to the input end of the buffer, and the output end of the buffer is used to connect to the input end of the circuit board to be tested; the first end of the feedback resistor R7 is connected to the output end of the buffer, and the second end of the feedback resistor R7 is connected to the output end of the first filter; the feedback resistor R7 is used to ensure the integrity and reliability of the test signal.
[0051] The first filter and the second filter form a second-order bandpass filter; the second-order bandpass filter, the buffer, and the feedback resistor form a second-order active bandpass filter; the signal higher than the first set frequency and lower than the second set frequency is filtered out, that is, the unnecessary frequency part is effectively filtered out, so as to ensure that the signal output to the circuit board to be tested is controlled at 1k-10kHz, and the amplitude of the test signal output by the second-order bandpass filter does not change after passing through the buffer, so as to filter the amplified test signal, and output it to the circuit board to be tested after the buffering treatment of the buffer after filtering. Use a second-order active bandpass filter to filter the unnecessary signal, the frequency response in the passband is flat, the stopband attenuation is fast, the signal is distortion-free, the response rate is fast, and the conversion rate is high; as other implementations, passive filters can also be used, or filters with higher orders can be used, that is, passive (multi-order) bandpass filters can be used.
[0052] The first filter and the second filter both include filter resistors and filter capacitors; Figure 2 As shown, the first filter includes a first filter resistor R4 and a first filter capacitor C1; the second filter includes a second filter resistor R5 and a second filter capacitor C2; the first end of the first filter resistor R4 is connected to the output end of the amplification unit 21, the second end of the first filter resistor R4 is connected to the first end of the second filter capacitor C2, and the second end of the second filter capacitor C2 is connected to the buffer; the first end of the first filter capacitor C1 is connected to the second end of the first filter resistor R4, and the second end of the first filter capacitor C1 is grounded; the first end of the second filter resistor R5 is connected to the second end of the second filter capacitor C2, and the second end of the second filter resistor R5 is grounded.
[0053] like Figure 2 As shown, the buffer includes a second operational amplifier U2 and a third resistor R6; the non-inverting input terminal of the second operational amplifier U2 is connected to the output terminal of the second filter, the inverting input terminal of the second operational amplifier U2 is connected to the first terminal of the third resistor R6, and the second terminal of the third resistor R6 is connected to the output terminal of the second operational amplifier U2.
[0054] In this embodiment, Figure 3 As shown, the conversion module 30 includes at least one group of conversion units and a fourth resistor R8, the two input ends of each group of conversion units are connected to the output end of the circuit board to be tested, the conversion unit is used to convert the differential signal output by the circuit board to be tested and then output a single-ended signal, and the single-ended signal is output through the fourth resistor R8; for example, the conversion module 30 adopts a chip X that can convert the differential into a single-ended signal, and after a group of conversion units of the chip X convert the differential signal with an amplitude of 5V output by the circuit board to be tested, the actual frequency of the output is consistent with the set frequency of the test signal generated by the main control module, i.e., FPGA.
[0055] In this embodiment, Figure 3 As shown, the buffer module 40 includes a third operational amplifier U3 and a fifth resistor R9; the first end of the fifth resistor R9 is connected to the inverting input end of the third operational amplifier U3, the second end of the fifth resistor R9 is connected to the output end of the third operational amplifier U3, and the inverting input end of the third operational amplifier U3 is connected to the output end of the conversion unit via the fourth resistor R8 to receive a single-ended signal; the cache module performs buffering processing on the converted single-ended signal to eliminate external noise interference and improve information quality. The buffer module formed by the third operational amplifier U3 has a large input impedance, a small output impedance, and a high load capacity. It plays a role of impedance transformation in the circuit and also plays a buffering role for the front and back stages; the buffered single-ended signal is input to the main control module, i.e., FPGA, for processing. The buffered signal frequency remains unchanged, and the amplitude becomes +3.3V (the operational amplifier is powered by +3.3V, so the maximum output voltage is also +3.3V).
[0056] In this embodiment, the indication module 50 includes a display unit and / or a sound unit. The display unit includes an LED light, for example, the light is on to indicate that the test has passed, and if the light is off, it indicates that the test has not passed; the display unit may also include an electronic display screen, for example, the electronic display screen directly displays words such as "pass / fail", "success / failure", etc. The sound unit includes a speaker for playing a preset sound signal, and the preset sound signal allows the technician to learn the test results more quickly and timely.
[0057] When the display unit includes an LED lamp, such as Figure 4 As shown, the display unit includes a sixth resistor R10, a seventh resistor R11, a transistor Q, an LED lamp and a pull-up resistor R12; the first end of the sixth resistor R10 is connected to the second output end of the main control module 10, the second end of the sixth resistor R10 is connected to the base of the transistor Q, the emitter of the transistor Q is grounded, the collector of the transistor Q is connected to the cathode of the LED lamp, and the anode of the LED lamp is connected to the power supply through the pull-up resistor R12; the first end of the seventh resistor R11 is connected to the base of the transistor Q, and the second end of the seventh resistor R11 is connected to the emitter of the transistor Q. The FPGA of the main control module detects and processes the single-ended signal after passing through the buffer module to obtain the actual frequency of the single-ended signal, and judges the actual frequency of the single-ended signal with the set frequency of the output test signal. If the frequencies are judged to be consistent for multiple times, a voltage signal with an amplitude of +3.3V is output, the transistor Q is turned on, and the LED is on, otherwise it is not on.
[0058] The present application can perform functional testing on the small signal amplifier circuit board on the mass spectrometer and automatically output the test results to effectively control the yield rate of the small signal amplifier circuit board, further improve the efficiency of mass spectrometer assembly and debugging, and save costs.
[0059] The test system of the embodiment of the present application includes a test circuit and a circuit board to be tested. The circuit board to be tested is a small signal amplifier circuit board of a mass spectrometer, and of course it can also be a signal amplifier board of other instruments. Different circuit boards to be tested have different set frequencies of test signals and / or different waveforms of test signals.
[0060] It can be understood that the test circuit options in the above embodiment are also applicable to this embodiment, so they will not be described again here.
[0061] The above description is only a specific implementation manner of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application.
Claims
1. A test circuit, characterized in that: It includes a main control module, a processing module and a conversion module; The main control module is used to output a test signal of a set frequency; The input end of the processing module is connected to the first output end of the main control module, and the processing module is used to process the test signal and then input it to the input end of the circuit board to be tested; The input end of the conversion module is used to connect to the output end of the circuit board to be tested, and the conversion module is used to convert the differential signal output by the circuit board to obtain a single-ended signal; The main control module is also used to detect the actual frequency of the single-ended signal, and compare the actual frequency with the set frequency of the test signal to obtain a test result.
2. The test circuit according to claim 1, characterized in that: Also included is an indication module; The input end of the indication module is connected to the second output end of the main control module; the indication module is used to receive the test result and indicate the test result.
3. The test circuit according to claim 1, characterized in that: Also includes a buffer module; The input end of the buffer module is the output end of the conversion module, the output end of the buffer module is connected to the input end of the main control module, and the buffer module performs buffering processing on the single-ended signal and then inputs it into the main control module.
4. The test circuit according to claim 1, characterized in that: The processing module includes an amplification unit and a filtering unit; The input end of the amplifying unit is connected to the first output end of the main control module, and the amplifying unit is used to amplify the test signal to match the circuit board to be tested; The input end of the filtering unit is connected to the output end of the amplifying unit, and the output end of the filtering unit is connected to the input end of the circuit board to be tested; the filtering unit is used to filter the test signal after amplification and output it to the circuit board to be tested after filtering.
5. The test circuit according to claim 4, characterized in that: The filtering unit includes a first filter, a second filter and a buffer; The input end of the first filter is connected to the output end of the amplifying unit, the output end of the first filter is connected to the input end of the second filter, the output end of the second filter is connected to the input end of the buffer, and the output end of the buffer is used to connect to the input end of the circuit board to be tested; The amplified test signal is input to the buffer after being filtered by the first filter and the second filter, and the buffer further performs buffer processing on the filtered test signal and outputs it to the circuit board to be tested.
6. The test circuit according to claim 5, characterized in that: The filtering unit further includes a feedback resistor; a first end of the feedback resistor is connected to an output end of the buffer, and a second end of the feedback resistor is connected to an input end of the second filter.
7. The test circuit according to claim 1, characterized in that: The conversion module includes at least one group of conversion units; the two input ends of each group of the conversion units are connected to the output end of the circuit board to be tested, and the conversion unit is used to convert the differential signal output by the circuit board to be tested and then output the single-ended signal.
8. The test circuit according to claim 2, characterized in that: The indication module includes a display unit and / or a sound unit; The display unit includes an LED light or an electronic display screen; different display modes of the LED light correspond to different test results; the electronic display screen displays the test results in a preset manner; The sound unit includes a speaker for playing a preset sound signal.
9. The test circuit according to claim 1, characterized in that: The main control module includes an FPGA, and the FPGA outputs the test signal in a frequency sweeping form.
10. A testing system, characterized in that: It comprises a test circuit as described in any one of claims 1 to 9 and a circuit board to be tested.