Waveform generator

Abstract

The utility model provides a waveform generator, which comprises a microprocessor, a pulse width modulation (PWM) conversion circuit, a first waveform oscillation circuit, a second waveform oscillation circuit, an energy storage capacitor and a constant current power supply, the output end of the PWM conversion circuit is electrically connected with the input end of the first waveform oscillation circuit and the input end of the second waveform oscillation circuit, and the first waveform oscillation circuit and the second waveform oscillation circuit each comprise a high-speed semiconductor switch. The waveform generator provided by the utility model can generate multi-frequency-point damped oscillation waveforms, a high-speed semiconductor switch is adopted in the waveform oscillation circuit, the waveform rise time is short, the repetition frequency is high, and the accuracy, reliability and strict degree of test are improved; the device is simple in structure, stable in output characteristic and wide in output voltage range, can meet different test requirements, and can accurately evaluate the immunity performance of the automobile electronic equipment in a complex electromagnetic environment.

Description

Technical Field

[0001] This utility model relates to the field of electromagnetic compatibility testing technology, and in particular to waveform generators. Background Technology

[0002] With the rapid development of automotive electronics technology, more and more sophisticated electronic devices are integrated into automobiles. These devices operate in complex electromagnetic environments and may be subject to electromagnetic interference from external or internal sources, thus affecting their normal operation. Therefore, testing the electromagnetic compatibility (EMC) of automotive electronic equipment is particularly important.

[0003] Induced noise immunity testing is a crucial step in electromagnetic compatibility (EMC) testing, designed to assess the immunity of electronic equipment to induced noise of specific frequencies and amplitudes. Traditional waveform generators mostly employ LC oscillation circuits based on the principle of mechanical relay switching. These circuits have numerous drawbacks, limiting the application range of the waveform generators.

[0004] Traditional test waveform generators have the following drawbacks:

[0005] 1. Low operating frequency. Due to the slow response speed of mechanical relay switches, they cannot meet the requirements of high repetition frequency.

[0006] 2. Limited operating voltage and switching power make it difficult to withstand high-voltage and high-power testing applications.

[0007] 3. Jitter generates noise. Mechanical relay switches generate jitter during switching, which introduces additional noise components, affecting the purity and stability of the waveform generated by the waveform generator.

[0008] 4. Poor stability. Due to wear and aging of the mechanical structure, mechanical relay switches have poor long-term stability, which may cause waveform parameters to drift.

[0009] 5. Large size and heavy weight, resulting in high testing costs. Utility Model Content

[0010] The purpose of this invention is to provide a waveform generator that can solve one or more of the problems in the prior art mentioned above.

[0011] According to one aspect of the present invention, a waveform generator is provided, comprising a microprocessor, a PWM conversion circuit, a first waveform oscillation circuit, a second waveform oscillation circuit, an energy storage capacitor, and a constant current power supply. The output terminal of the microprocessor is electrically connected to the input terminal of the PWM conversion circuit. The output terminal of the PWM conversion circuit is electrically connected to the input terminals of the first waveform oscillation circuit and the second waveform oscillation circuit, respectively. The output terminal of the constant current power supply is electrically connected to the input terminal of the energy storage capacitor. The output terminal of the energy storage capacitor is electrically connected to the input terminal of the second waveform oscillation circuit. Both the first waveform oscillation circuit and the second waveform oscillation circuit include high-speed semiconductor switches.

[0012] In some implementations, a residual voltage discharge module is also included, which is electrically connected to the PWM conversion circuit and the energy storage capacitor, respectively.

[0013] In some implementations, an auxiliary power supply is also included, the output of which is electrically connected to both the microprocessor and the constant current power supply.

[0014] In some implementations, the microprocessor communicates with the host computer via a LAN port.

[0015] In some implementations, the waveform generator uses a 6U standard chassis.

[0016] In some embodiments, the waveform generator chassis is provided with a panel, which includes an LCD screen, a power switch, an output port, and indicator lights. The LCD screen is electrically connected to the microprocessor, the power switch is electrically connected to the auxiliary power supply, the output port is connected to the output terminal of the first waveform oscillation circuit or the second waveform oscillation circuit, and the indicator lights are electrically connected to the microprocessor.

[0017] In some implementations, an output adapter board is provided on the side of the panel facing the inside of the chassis. The output adapter board is used to connect the output terminals and output ports of the first waveform oscillation circuit and the second waveform oscillation circuit.

[0018] In some implementations, an I / O control module is also included, which is electrically connected to the microprocessor and is used to communicate with external devices.

[0019] In some implementations, the constant current power supply is a constant current 4KV high-voltage power supply.

[0020] In some implementations, a first waveform oscillation circuit is used to generate damped oscillation waveforms of 0.1 MHz and 5 MHz, and a second waveform oscillation circuit is used to generate damped oscillation waveforms of 10 MHz, 30 MHz, and 100 MHz.

[0021] The waveform generator provided by this utility model can generate multi-frequency damped oscillation waveforms. The high-speed semiconductor switch used in the waveform oscillation circuit has a short waveform rise time and a high repetition frequency, which improves the accuracy, reliability and rigor of the test. The output characteristics are stable and the output voltage range is wide, which can meet different test requirements and accurately evaluate the immunity performance of automotive electronic equipment in complex electromagnetic environments.

[0022] In addition, unless otherwise specified, all aspects of this utility model technical solution can be implemented by conventional means in the field. Attached Figure Description

[0023] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0024] Figure 1 This is a schematic diagram of the waveform generator provided in one embodiment of the present invention.

[0025] Figure 2 The equivalent circuit diagram of the first waveform oscillation circuit and the second waveform oscillation circuit in the waveform generator provided in an embodiment of the present invention is shown.

[0026] Figure 3 An equivalent circuit diagram of a high-speed semiconductor switch drive in a waveform generator provided in an embodiment of this utility model.

[0027] Figure 4 This is a front view of the panel of a waveform generator provided in an embodiment of the present invention.

[0028] Figure 5 This is a schematic diagram of the structure of a waveform generator with its panel facing the inside of the chassis, according to an embodiment of the present invention.

[0029] Figure 6 This is a side view of the internal structure of the chassis of a waveform generator provided in an embodiment of the present invention. Detailed Implementation

[0030] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0031] Example:

[0032] In this embodiment, please refer to the appendix to the specification. Figure 1 It provides a waveform generator.

[0033] The waveform generator may include a microprocessor 1, a PWM conversion circuit 2, a first waveform oscillation circuit 3, a second waveform oscillation circuit 4, an energy storage capacitor 5, a constant current power supply 6, a residual voltage discharge module 7, an auxiliary power supply 8, a LAN port 9, and an IO control module 10.

[0034] Microprocessor 1 can be an embedded microprocessor based on the ARM Cortex-M STM32. Microprocessor 1 can control waveform generation according to user-defined waveform parameters, and can also store and analyze the data.

[0035] The output terminal of the microprocessor 1 is electrically connected to the input terminal of the PWM conversion circuit 2. The output terminal of the PWM conversion circuit 2 is electrically connected to the input terminal of the first waveform oscillation circuit 3 and the input terminal of the second waveform oscillation circuit 4, respectively. The PWM conversion circuit 2 is used to convert digital signals into analog signals to drive the first waveform oscillation circuit 3 and the second waveform oscillation circuit 4.

[0036] The constant current power supply 6 is a constant current high-voltage power supply used to provide energy to the second waveform oscillation circuit 4, ensuring the stability and accuracy of the waveform output. The output terminal of the constant current power supply 6 is electrically connected to the input terminal of the energy storage capacitor 5, and the output terminal of the energy storage capacitor 5 is electrically connected to the input terminal of the second waveform oscillation circuit 4. The constant current power supply 6 can be a constant current 4KV high-voltage power supply.

[0037] The residual voltage discharge module 7 is electrically connected to the PWM conversion circuit 2 and the energy storage capacitor 5. The residual voltage discharge module 7 may include a relay and a resistor, with one end of the resistor grounded.

[0038] The output of auxiliary power supply 8 is electrically connected to microprocessor 1 and constant current power supply 6, respectively. Therefore, auxiliary power supply 8 can provide a stable DC power supply to the waveform generator.

[0039] Microprocessor 1 can communicate with the host computer via LAN port 9, which facilitates remote monitoring by the host computer and data transmission between the host computer and the waveform generator.

[0040] The IO control module 10 is electrically connected to the microprocessor 1 and is used to communicate with external devices.

[0041] Both the first waveform oscillation circuit 3 and the second waveform oscillation circuit 4 include high-speed semiconductor switches. The first waveform oscillation circuit 3 can be used to generate damped oscillation waveforms at 0.1MHz and 5MHz, while the second waveform oscillation circuit 4 can be used to generate damped oscillation waveforms at 10MHz, 30MHz, and 100MHz. Therefore, the first waveform oscillation circuit 3 and the second waveform oscillation circuit 4 can generate damped oscillation waveforms at five frequencies (0.1MHz, 5MHz, 10MHz, 30MHz, and 100MHz) that meet the requirements of Section 6.3 of the TOYOTA TSC0502G automotive standard. All waveforms have a rise time of less than 10ns, a repetition frequency exceeding 100Hz, and a maximum actual output voltage of 600V.

[0042] Reference manual attached Figure 2 The diagram shows the circuit diagrams of the first and second waveform oscillation circuits. HV POWER IN represents the voltage input, and PULSE OUT represents the waveform output. Both the first and second waveform oscillation circuits employ a high-frequency resonant capacitor, a resonant inductor, and a high-speed semiconductor switch Q to generate and output high-frequency waveforms. The high-speed semiconductor switch Q is driven by the output signal of the PWM conversion circuit. By setting different parameters for each circuit element in the first waveform oscillation circuit 3 and the second waveform oscillation circuit 4, attenuated oscillation waveforms at different frequency points can be output. All impedances in the first waveform oscillation circuit 3 and the second waveform oscillation circuit 4 are set to 50Ω to better match the EUT (Equipped Under Test) and improve the accuracy and reliability of the test.

[0043] In optional embodiments, the first waveform oscillation circuit 3 and the second waveform oscillation circuit 4 may include a high-speed semiconductor switch array. (See attached specification) Figure 3 The diagram shows the equivalent circuit diagram of the high-speed semiconductor switch array drive in the waveform generator. The high-speed semiconductor switch array includes high-speed semiconductor switches Q1, Q2, ..., Qn. Each high-speed semiconductor switch in the array uses a MOSFET power transistor with a relatively small gate input capacitance, enabling the high-speed semiconductor switch array to turn on quickly. Each MOSFET power transistor in the high-speed semiconductor switch array is driven independently but synchronously by T1, T2, ..., and Tn, further ensuring the performance and stability of the output waveforms of the first waveform oscillation circuit 3 and the second waveform oscillation circuit 4.

[0044] Reference manual attached Figure 4-6The diagram shows a waveform generator chassis and a partial structural diagram of the internal components. This waveform generator can be designed using a standard 6U chassis.

[0045] A panel 11 can be installed on the chassis of the waveform generator, see the attached instruction manual. Figure 4 The diagram shows a front view of the waveform generator's panel. The panel 11 may include an LCD screen 12, a power switch 13, an output port 14, and indicator lights 15.

[0046] The LCD screen 12 is electrically connected to the microprocessor 1. Users can set waveform parameters, such as voltage, frequency and time, through the LCD screen. After receiving the waveform parameters, the microprocessor 1 controls the first waveform oscillation circuit 3 or the second waveform oscillation circuit 4 to output the corresponding waveform.

[0047] The power switch 13 is electrically connected to the auxiliary power supply 8, which is used to provide a stable DC power supply for the waveform generator.

[0048] Output port 14 is connected to the output terminal of the first waveform oscillation circuit 3 or the second waveform oscillation circuit 4. Multiple output ports 14 can be set, and each output port 14 corresponds to the output of a damped oscillation waveform at a frequency point.

[0049] Indicator light 15 is electrically connected to microprocessor 1. The number of indicator lights 15 is the same as the number of output ports 14. Indicator lights 15 can be LEDs. Indicator lights 15 are used to display the waveform output status of the corresponding output port 14.

[0050] Reference manual attached Figure 5 The diagram shows a schematic of the waveform generator's panel facing inwards from the chassis. An output adapter board 16 is located on the side of the panel facing inwards from the chassis. The output adapter board 16 is used to connect the output terminals of the first waveform oscillation circuit 3 and the second waveform oscillation circuit 4 to the output port 14.

[0051] Reference manual attached Figure 6 The diagram shows a side view of the internal structure of the waveform generator chassis. Ventilation openings 18 are provided on the side wall of the chassis for heat dissipation, ensuring stable operation of the waveform generator.

[0052] The chassis has two vertically arranged layers. To make efficient use of the internal space, the electrical components of the second waveform oscillation circuit 4 and the first waveform oscillation circuit 3 can be placed on the two layers of the chassis respectively. Refer to the attached instruction manual. Figure 6 The high-speed semiconductor switch 17 is located on the lower layer, while the high-frequency resonant capacitor, resonant inductor, and impedance are located on the upper layer. This makes the internal structure of the chassis compact, effectively reducing the size of the waveform generator, making it easy to carry and install, and reducing testing costs.

[0053] The waveform generator provided by this invention can meet the requirements of immune test for induced noise of automotive electronic equipment, generating a damped oscillation waveform with both frequency and waveform conforming to the test requirements. Through the configuration of a microprocessor, a first waveform oscillation circuit, and a second waveform oscillation circuit, the precise generation and control of the damped oscillation waveform is achieved, which not only improves the quality and stability of the waveform but also reduces testing costs and maintenance difficulty. The high-speed semiconductor switch used in the waveform oscillation circuit has a short waveform rise time and high repetition frequency, improving the accuracy, reliability, and rigor of the test. It achieves precise generation of high-frequency waveforms and stable output characteristics, with stable output characteristics and a wide output voltage range, meeting different test requirements. Ultimately, it enables accurate evaluation of the immune performance of automotive electronic equipment in complex electromagnetic environments. The waveform generator has a compact internal layout, making it easy to carry and install, thus reducing testing costs.

[0054] The above description is only an optional embodiment of this utility model. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of this utility model, and these improvements and modifications should also be considered within the protection scope of this utility model.

Claims

1. A waveform generator, characterized by, It comprises a microprocessor (1), a PWM conversion circuit (2), a first waveform oscillation circuit (3), a second waveform oscillation circuit (4), an energy storage capacitor (5) and a constant current power supply (6), The output end of the microprocessor (1) is electrically connected with the input end of the PWM conversion circuit (2), the output end of the PWM conversion circuit (2) is electrically connected with the input end of the first waveform oscillation circuit (3) and the input end of the second waveform oscillation circuit (4) respectively, the output end of the constant current power supply (6) is electrically connected with the input end of the energy storage capacitor (5), and the output end of the energy storage capacitor (5) is electrically connected with the input end of the second waveform oscillation circuit (4), The first waveform oscillation circuit (3) and the second waveform oscillation circuit (4) both comprise a high-speed semiconductor switch (17).

2. The waveform generator of claim 1, wherein, It also comprises a residual voltage discharge module (7) which is electrically connected with the PWM conversion circuit (2) and the energy storage capacitor (5) respectively.

3. The waveform generator of claim 1, wherein, It also comprises an auxiliary power supply (8), and the output end of the auxiliary power supply (8) is electrically connected with the microprocessor (1) and the constant current power supply (6) respectively.

4. The waveform generator of claim 1, wherein, The microprocessor (1) is in communication connection with an upper computer through a LAN port (9).

5. The waveform generator of claim 1, wherein, The waveform generator adopts a 6U standard case.

6. The waveform generator of claim 3, wherein, A panel (11) is arranged on the case of the waveform generator, an LCD screen (12), a power switch (13), an output port (14) and an indicator light (15) are arranged on the panel (11), the LCD screen (12) is electrically connected with the microprocessor (1), the power switch (13) is electrically connected with the auxiliary power supply (8), the output port (14) is connected with the output end of the first waveform oscillation circuit (3) or the second waveform oscillation circuit (4), and the indicator light (15) is electrically connected with the microprocessor (1).

7. The waveform generator of claim 6, wherein, An output adapter plate (16) is arranged on the side of the panel (11) facing the case, and the output adapter plate (16) is used for connecting the output end of the first waveform oscillation circuit (3) and the second waveform oscillation circuit (4) with the output port (14).

8. The waveform generator of claim 1, wherein, It also comprises an IO control module (10) which is electrically connected with the microprocessor (1) and is used for communicating with external equipment.

9. The waveform generator of claim 1, wherein, The constant current power supply (6) is a constant current 4KV high voltage power supply.

10. The waveform generator of claim 1, wherein, The first waveform oscillation circuit (3) is used for generating 0.1MHz and 5MHz attenuated oscillation waveforms, and the second waveform oscillation circuit (4) is used for generating 10MHz, 30MHz and 100MHz attenuated oscillation waveforms. The first waveform oscillation circuit (3) is used for generating 0.1MHz and 5MHz attenuated oscillation waveforms, and the second waveform oscillation circuit (4) is used for generating 10MHz, 30MHz and 100MHz attenuated oscillation waveforms.

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