Test circuit and test system
By designing automated testing circuits, the problems of poor accuracy and low efficiency of manual testing of small signal amplification circuit boards in mass spectrometers were solved, achieving rapid and accurate test results and efficient production.
Patent Information
- Application Number
- CN202423125717.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-18
- Publication Date
- 2025-12-09
- Estimated Expiration
- 2034-12-18
AI Technical Summary
The accuracy of the output signal from the small-signal amplification circuit board of a mass spectrometer is poor and the testing efficiency is low, which cannot meet the needs of high-efficiency production.
Design a test circuit that includes a main control module, a processing module, a conversion module, a buffer module, and an indicator module. By automating the processing of test signals and results, the reliance on technical personnel can be reduced, and fast and accurate testing can be achieved.
This improved the detection efficiency and accuracy of the small-signal amplification circuit board in the mass spectrometer, reduced the impact of noise interference on test results, and increased production efficiency and yield.
Smart Images
Figure CN223650682U_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of electronic circuit technology, and in particular to a test circuit and test system. Background Technology
[0002] Circuit board technology is advancing rapidly, and corresponding circuit board testing technology is also constantly improving. Circuit board testing technology generally involves measuring voltage, current, waveform, and power. That is, the excitation source outputs a test signal to the circuit board under test, while the circuit board outputs a result signal to an oscilloscope. The circuit board is then manually observed to determine whether the output signal meets the standards, thus judging whether the circuit board is qualified or not.
[0003] For the small signal amplification circuit board of a mass spectrometer, manually observing the output signal of the signal amplification circuit board will heavily depend on the experience and ability of the technicians, thus affecting the accuracy of the judgment results; at the same time, the manual judgment process is slow and cannot adapt to the high production efficiency of the mass spectrometer. Utility Model Content
[0004] In view of this, embodiments of this application provide a test circuit and a test system that can effectively solve the problems of poor measurement accuracy and low test efficiency caused by manually testing the small signal amplification circuit board of a mass spectrometer.
[0005] In a first aspect, embodiments of this application provide 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 at a set frequency;
[0007] The input terminal of the processing module is connected to the first output terminal of the main control module. The processing module is used to process the test signal and then input it to the input terminal of the circuit board under test.
[0008] The input terminal of the conversion module is used to connect to the output terminal of the circuit board under test, and the conversion module is used to convert the differential signal output by the circuit board under test 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 the test result.
[0010] In some embodiments, the test circuit further includes an indicator module;
[0011] The input terminal of the indicator module is connected to the second output terminal of the main control module; the indicator module is used to receive the test results and indicate the test results.
[0012] In some embodiments, the test circuit further includes a buffer module;
[0013] The input terminal of the buffer module is connected to the output terminal of the conversion module, and the output terminal of the buffer module is connected to the input terminal of the main control module. The buffer module buffers the single-ended signal and then inputs it to the main control module.
[0014] In some embodiments, the processing module includes an amplification unit and a filtering unit;
[0015] The input terminal of the amplification unit is connected to the first output terminal of the main control module. The amplification unit is used to amplify the test signal to match the circuit board under test.
[0016] The input terminal of the filtering unit is connected to the output terminal of the amplification unit, and the output terminal of the filtering unit is connected to the input terminal of the circuit board under test. The filtering unit is used to filter the amplified test signal and output the filtered signal to the circuit board under test.
[0017] In some embodiments, the filtering unit includes a first filter, a second filter, and a buffer;
[0018] The input terminal of the first filter is connected to the output terminal of the amplification unit, the output terminal of the first filter is connected to the input terminal of the second filter, the output terminal of the second filter is connected to the input terminal of the buffer, and the output terminal of the buffer is used to connect to the input terminal of the circuit board under test.
[0019] The amplified test signal is filtered by the first filter and the second filter and then input to the buffer. The buffer then buffers the filtered test signal and outputs it to the circuit board under test.
[0020] In some embodiments, the filtering unit further includes a feedback resistor; a first end of the feedback resistor is connected to the output of the buffer, and a second end of the feedback resistor is connected to the input of the second filter.
[0021] In some embodiments, the conversion module includes at least one set of conversion units; the two input terminals of each set of conversion units are connected to the output terminal 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 output the single-ended signal.
[0022] In some embodiments, the indicating module includes a display unit and / or a sound unit;
[0023] The display unit includes LED lights or an electronic display screen; different display modes of the LED lights 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, which outputs the test signal in a frequency sweep manner.
[0026] Fourthly, embodiments of this application provide a testing system, including the test circuit and the circuit board under test as described above.
[0027] The embodiments of this application have the following beneficial effects:
[0028] The main control module of the test circuit in this application actively outputs a test signal and performs frequency processing on the test signal and the single-ended signal obtained from the output processing of the circuit board under test. The automated processing of the main control module reduces the dependence on manual labor by technicians in the testing process. Moreover, the automated processing of the main control module is fast and efficient, which can further improve the testing efficiency and accuracy of the circuit board under test. Attached Figure Description
[0029] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.
[0030] Figure 1 A schematic diagram of the principle structure of a test circuit in an embodiment of this application is shown;
[0031] Figure 2 A circuit diagram of a processing module in an embodiment of this application is shown;
[0032] Figure 3 A circuit diagram of a conversion module in an embodiment of this application is shown;
[0033] Figure 4 A circuit diagram of an indicator module in an embodiment of this application is shown.
[0034] Explanation of key component symbols:
[0035] 10-Main control module; 20-Processing module; 21-Amplification unit; 22-Filtering unit; 30-Conversion module; 40-Buffer module; 50-Indicator module. Detailed Implementation
[0036] The technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments.
[0037] The components of the embodiments of this application described and illustrated in the accompanying drawings can be arranged and designed in a variety of different configurations. Therefore, the following detailed description of the embodiments of this application provided in the drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.
[0038] In the following text, the terms "comprising," "having," and their cognates, which may be used in various embodiments of this application, are intended only to indicate a particular feature, number, step, operation, element, component, or combination thereof, and should not be construed as primarily excluding the presence of one or more other features, numbers, steps, operations, elements, components, or combinations thereof, or adding the possibility of one or more combinations thereof. Furthermore, the terms "first," "second," "third," etc., are used only for distinguishing descriptions and should not be construed as indicating or implying relative importance.
[0039] Unless otherwise specified, all terms used herein (including technical and scientific terms) shall have the same meaning as commonly understood by one of ordinary skill in the art to which the various embodiments of this application pertain. Terms (such as those defined in commonly used dictionaries) shall be interpreted as having the same meaning as in their contextual meaning in the relevant technical field and shall not be construed as having an idealized or overly formal meaning, unless clearly defined in the various embodiments of this application.
[0040] The following detailed description of some embodiments of this application is provided in conjunction with the accompanying drawings. Unless otherwise specified, the following embodiments and features can be combined with each other.
[0041] When performing functional tests on the small-signal amplifier circuit board of a mass spectrometer, manual operation is complex, and the parameters of the excitation source that generates the test signal need to be set manually, which takes a long time. This application proposes an intelligent and automated test circuit to improve test production efficiency. Furthermore, by processing the output signal of the small-signal amplifier circuit board, the interference of noise level on the judgment of test results is reduced, thereby further improving the reliability of the test results.
[0042] The test circuit will be described below with reference to some specific embodiments.
[0043] Figure 1 A schematic diagram of the principle structure of a test circuit according to an embodiment of this 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 indicator module 50.
[0044] The input terminal of the processing module 20 is connected to the first output terminal of the main control module 10, and the output terminal of the processing module 20 is used to connect to the input terminal of the circuit board under test. The processing module 20 processes the test signal and inputs it to the input terminal of the circuit board under test. The circuit board under test is a small signal amplification circuit board of a mass spectrometer, or it can be a signal amplification board of other instruments. The set frequency of the test signal and / or the waveform of the test signal are different depending on the circuit board under test.
[0045] The input terminal of the conversion module 30 is used to connect to the output terminal of the circuit board under test, and the output terminal of the conversion module 30 is used to connect to the input terminal of the buffer module 40. The output terminal of the buffer module 40 is connected to the output terminal of the main control module 10, and the second output terminal of the main control module 10 is connected to the indicator module 50. The conversion module 30 converts the differential signal output by the circuit board under test to obtain a single-ended signal. After being buffered by the buffer module 40, the single-ended signal is input to the main control module 10. 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 to the indicator module so that the indicator module can intuitively indicate the test result.
[0046] In the test circuit of this application, the main control module actively sends a test signal of a set frequency. After the test signal is processed, it is input to the circuit board under test and outputs a differential signal. After the differential signal is converted and processed, the main control module detects the actual frequency of the feedback and compares the actual frequency with the set frequency to obtain the test result quickly and accurately. The test result can be intuitively indicated by the indicator module.
[0047] In this embodiment, the main control module uses an FPGA. The FPGA simulates the input signal of the small-signal amplifier circuit board. The FPGA outputs a square wave signal with a duty cycle of 50% and a set frequency of 1kHz-10kHz as the test signal. This test signal is output in a frequency sweep format, with a signal amplitude of 3.3V. Frequency sweep refers to the process of a signal continuously changing from high to low (or from low to high) within a frequency band, often used in electronic measurements to measure the impedance and transmission characteristics of networks. For example, after outputting a 1kHz signal for 1 second, it switches to outputting a 2kHz signal for 1 second, and so on. The set frequency of the test signal is not limited to one, but rather ranges from low to high, ensuring comprehensive frequency detection and effectively reducing the actual failure rate of the circuit board during operation.
[0048] In this embodiment, the processing module 20 includes an amplification unit 21 and a filtering unit 22. The input terminal of the amplification unit 21 is connected to the first output terminal of the main control module 10. The amplification unit 21 amplifies the test signal to match the circuit board under test. The input terminal of the filtering unit 22 is connected to the output terminal of the amplification unit 21. The output terminal of the filtering unit 22 is connected to the input terminal of the circuit board under test. The amplified test signal is filtered to remove unwanted frequency components from the signal and is then output to the circuit board under test after filtering.
[0049] In this embodiment, as 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 terminal of the first resistor R1 is grounded, and the second terminal of the first resistor R1 is connected to the non-inverting input terminal of the first operational amplifier U1. The first terminal of the third resistor R1 is connected to the output terminal of the main control module 10, and the second terminal of the third resistor R1 is connected to the inverting input terminal of the first operational amplifier U1. The first terminal of the third resistor R3 is connected to the inverting input terminal of the first operational amplifier U1, and the second terminal of the third resistor R3 is connected to the output terminal of the first operational amplifier U1. The second resistor R2, the third resistor R3, and the first operational amplifier U1 constitute an inverting amplifier, which inversely amplifies the 3.3V test signal received by the first operational amplifier U1. After inversion amplification, the amplitude of the test signal becomes -200mV, while the frequency remains unchanged, to match the input requirements of the circuit under test. Alternatively, a MOSFET can be used to control a constant voltage source to output a square wave test signal.
[0050] In this embodiment, as Figure 2 As shown, the filtering unit 22 includes a first filter, a second filter, a buffer, and a feedback resistor R7. The input terminal of the first filter is connected to the output terminal of the amplification unit 21, the output terminal of the first filter is connected to the input terminal of the second filter, the output terminal of the second filter is connected to the input terminal of the buffer, and the output terminal of the buffer is used to connect to the input terminal of the circuit board under test. The first terminal of the feedback resistor R7 is connected to the output terminal of the buffer, and the second terminal of the feedback resistor R7 is connected to the output terminal of the first filter. The feedback resistor R7 is used to ensure the integrity and reliability of the test signal.
[0051] The first and second filters form a second-order bandpass filter. This second-order bandpass filter, along with a buffer and a feedback resistor, constitutes a second-order active bandpass filter. Signals above a first set frequency and below a second set frequency are filtered out, effectively removing unwanted frequency components. This ensures the signal output to the circuit board under test is controlled within the 1kHz-10kHz range. The test signal output from the second-order bandpass filter has no amplitude change after passing through the buffer, thus filtering the amplified test signal. After filtering, the signal is buffered again before being output to the circuit board under test. Using a second-order active bandpass filter filters unwanted signals, resulting in a smooth frequency response within the passband, rapid stopband attenuation, no signal distortion, and a fast response and high slew rate. Alternatively, passive filters or higher-order filters, i.e., passive (multi-order) bandpass filters, can be used.
[0052] Both the first and second filters include filter resistors and filter capacitors; for example... 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 terminal of the amplifier 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 a 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 of the second operational amplifier U2 is connected to the output of the second filter, the inverting input of the second operational amplifier U2 is connected to the first end of the third resistor R6, and the second end of the third resistor R6 is connected to the output of the second operational amplifier U2.
[0054] In this embodiment, as Figure 3 As shown, the conversion module 30 includes at least one set of conversion units and a fourth resistor R8. The two input terminals of each set of conversion units are connected to the output terminals of the circuit board under test. The conversion unit is used to convert the differential signal output by the circuit board under test and output a single-ended signal. The single-ended signal is output through the fourth resistor R8. For example, the conversion module 30 uses a chip X that can convert differential signals into single-ended signals. After the set of conversion units of chip X converts the differential signal with an amplitude of 5V output by the circuit board under test, the actual frequency of the output is consistent with the set frequency of the test signal generated by the main control module, i.e., the FPGA.
[0055] In this embodiment, as 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 of the third operational amplifier U3, and the second end of the fifth resistor R9 is connected to the output of the third operational amplifier U3. The inverting input of the third operational amplifier U3 is connected to the output of the conversion unit via a fourth resistor R8 to receive single-ended signals. The buffer module buffers the converted single-ended signals to eliminate external noise interference and improve information quality. The buffer module, constructed using the third operational amplifier U3, has a large input impedance, a small output impedance, and a high load-carrying capacity. It plays the role of impedance transformation in the circuit and also acts as a buffer for the preceding and following stages. The buffered single-ended signal is input to the main control module, i.e., the FPGA, for processing. The frequency of the buffered signal remains unchanged, but 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 indicator module 50 includes a display unit and / or a sound unit. The display unit includes LEDs; for example, an illuminated LED indicates a passed test, while an off LED indicates a failed test. The display unit may also include an electronic display screen, for example, directly displaying words such as "Pass / Fail" or "Success / Failure." The sound unit includes a speaker for playing preset sound signals, which allow technicians to obtain test results more quickly and promptly.
[0057] When the display unit includes LED lights, such as Figure 4 As shown, the display unit includes a sixth resistor R10, a seventh resistor R11, a transistor Q, an LED, and a pull-up resistor R12. The first end of the sixth resistor R10 is connected to the second output terminal of the main control module 10, and 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, and the collector of the transistor Q is connected to the cathode of the LED. The anode of the LED 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 the buffer module to obtain the actual frequency of the single-ended signal. It compares the actual frequency of the single-ended signal with the set frequency of the output test signal. If the frequencies match multiple times, a voltage signal with an amplitude of +3.3V is output, the transistor Q conducts, and the LED lights up; otherwise, it does not light up.
[0058] This application enables functional testing of the small-signal amplification circuit board on a mass spectrometer and automatically outputs the test results, thereby effectively controlling the yield rate of the small-signal amplification circuit board, further improving the efficiency of mass spectrometer assembly and debugging, and saving weighing costs.
[0059] The test system of this application embodiment includes a test circuit and a circuit board under test. The circuit board under test is a small-signal amplification circuit board of a mass spectrometer, but it can also be a signal amplification board of other instruments. Different circuit boards under test result in different set frequencies and / or waveforms of the test signals.
[0060] It is understood that the test circuit options in the above embodiments are also applicable to this embodiment, so they will not be described again here.
[0061] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this 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 at a set frequency; The input terminal of the processing module is connected to the first output terminal of the main control module. The processing module is used to process the test signal and then input it to the input terminal of the circuit board under test. The input terminal of the conversion module is used to connect to the output terminal of the circuit board under test, and the conversion module is used to convert the differential signal output by the circuit board under test 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 the test result.
2. The test circuit according to claim 1, characterized in that, It also includes an indicator module; The input terminal of the indicator module is connected to the second output terminal of the main control module; the indicator module is used to receive the test results and indicate the test results.
3. The test circuit according to claim 1, characterized in that, It also includes a buffer module; The input terminal of the buffer module is connected to the output terminal of the conversion module, and the output terminal of the buffer module is connected to the input terminal of the main control module. The buffer module buffers the single-ended signal and then inputs it to 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 terminal of the amplification unit is connected to the first output terminal of the main control module. The amplification unit is used to amplify the test signal to match the circuit board under test. The input terminal of the filtering unit is connected to the output terminal of the amplification unit, and the output terminal of the filtering unit is connected to the input terminal of the circuit board under test. The filtering unit is used to filter the amplified test signal and output the filtered signal to the circuit board under test.
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 terminal of the first filter is connected to the output terminal of the amplification unit, the output terminal of the first filter is connected to the input terminal of the second filter, the output terminal of the second filter is connected to the input terminal of the buffer, and the output terminal of the buffer is used to connect to the input terminal of the circuit board under test. The amplified test signal is filtered by the first filter and the second filter and then input to the buffer. The buffer then buffers the filtered test signal and outputs it to the circuit board under test.
6. The test circuit according to claim 5, characterized in that, The filtering unit further includes a feedback resistor; the first end of the feedback resistor is connected to the output end of the buffer, and the second end of the feedback resistor is connected to the input end of the second filter.
7. The test circuit according to claim 1, characterized in that, The conversion module includes at least one set of conversion units; the two input terminals of each set of conversion units are connected to the output terminal 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 output the single-ended signal.
8. The test circuit according to claim 2, characterized in that, The indicator module includes a display unit and / or a sound unit; The display unit includes LED lights or an electronic display screen; different display modes of the LED lights 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, which outputs the test signal in a frequency sweep format.
10. A testing system, characterized in that, Includes the test circuit and the circuit board under test as described in any one of claims 1-9.