Wide-range electronic load device
By designing a wide-range electronic load device and employing a programmable control module and an electronic load module, low-cost, highly integrated, and fast-response current detection is achieved, solving the problem that traditional static loads cannot meet the requirements of dynamic loads. This device is suitable for automated testing equipment for electronic products.
Patent Information
- Application Number
- CN202520050068.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-09
- Publication Date
- 2026-02-10
- Estimated Expiration
- 2035-01-09
AI Technical Summary
Existing technologies are insufficient to meet the performance testing needs of diverse and complex products, especially in power supply testing. Traditional static load devices cannot meet the dynamic load requirements, and existing equipment is costly, bulky, and unsuitable for miniaturization design.
A wide-range electronic load device was designed, employing a programmable control module and an electronic load module, including an operational amplifier, an instrumentation amplifier, a multiplexer, a resistor module, and a relay module. The circuit is simple, enabling load switching across four current ranges. The relay switching is controlled by an MCU module, providing a load current range of 1uA to 10A with a response speed of μS.
It achieves a wide current range with low cost, high integration, small size, and fast response speed, making it suitable for automated testing equipment for electronic products and meeting the testing needs of diverse products.
Smart Images
Figure CN223897522U_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the technical field of automated testing, and in particular to a wide-range electronic load device. Background Technology
[0002] As products become increasingly diversified and complex, scientifically and rapidly testing their performance and specifications has become a major challenge. Resistors and resistance boxes, with their stepped adjustments, fixed resistance values, or fixed load characteristic curves, offer a limited range of load types and low power. However, actual loads are more complex, typically dynamic, and constantly changing with time and frequency. Traditional static loads are increasingly unable to meet the demands of power supply testing. Therefore, researchers both domestically and internationally have sought alternative load types, leading to the development of electronic loads composed of resistors, inductors, capacitors, transistors, and integrated circuits. Introducing power electronics and microcomputer technologies into load devices not only enables the realization of the basic functions of traditional static loads but also allows for software upgrades without modifying the hardware.
[0003] In applications requiring current calibration of test boards, achieving wide-range current calibration is crucial. Currently, instruments capable of wide-range current calibration include active meters and electronic load meters. However, most board-level electronic loads employ single-range current solutions, which are insufficient to meet wide-range current calibration requirements. Furthermore, building a calibration test platform using electronic load meters and DMMs has significant drawbacks: high cost (often tens of thousands of yuan), large size, and unsuitability for miniaturized fixture designs. Therefore, it is necessary to provide a wide-range electronic load device that is low-cost, highly integrated, compact, space-saving, offers a wide current range (1uA~10A load current), and features fast response with high-bandwidth operational amplifiers and MCU processing, achieving a response speed of up to µS. Utility Model Content
[0004] The technical problem to be solved by this utility model is to overcome the shortcomings of the prior art and provide a wide-range electronic load device that is low in cost, highly integrated, small in size, space-saving, has a wide current range (1uA~10A load current range), fast response, and high-bandwidth operational amplifier and MCU processing, with a response speed of up to µS.
[0005] The technical solution adopted by this utility model is as follows: This utility model includes a programmable control module and an electronic load module. The programmable control module is connected to the electronic load module. The electronic load module includes an operational amplifier, an instrumentation amplifier, a multiplexer, a resistor module, and a relay module. The non-inverting input terminal of the operational amplifier is connected to the programmable control module. The inverting input terminal and the output terminal of the operational amplifier are both connected to the output terminal of the instrumentation amplifier. The input terminal of the instrumentation amplifier is connected to the multiplexer. The multiplexer is connected to the relay module via the resistor module.
[0006] As can be seen from the above scheme, this application uses four current-range loads, providing a wide test current range. The switching of the relay module is controlled by the host computer sending commands to the slave computer, enabling switching between the four current-range loads. It adopts a board-based design, resulting in a small size, saving space, and a relatively low price, generally below 1000 yuan. Its small size and high portability allow for flexible integration with mechanical designs. It boasts high integration density, a wide current range (1uA~10A load current range), fast response (high-bandwidth operational amplifiers and MCU processing, achieving a response speed of µS), high integration, simple circuitry, and the ability to meet equivalent testing requirements. Its high integration density allows for large-scale application in automated testing equipment for electronic products.
[0007] In a preferred embodiment, the electronic load module further includes a MOS transistor, the gate of which is connected to the output of the operational amplifier, and the source of which is connected to the relay module.
[0008] In a preferred embodiment, the resistor module includes a first sampling resistor, a second sampling resistor, a third sampling resistor, and a fourth sampling resistor; the relay module includes a first relay, a second relay, a third relay, a fourth relay, and a fifth relay; the S1A and S1B terminals of the multiplexer are both connected to the first relay via the first sampling resistor; the S2A and S2B terminals of the multiplexer are both connected to the second relay via the second sampling resistor; the S3A and S3B terminals of the multiplexer are both connected to the third relay via the third sampling resistor; and the S4A and S4B terminals of the multiplexer are both connected to the fourth and fifth relays via the fourth sampling resistor.
[0009] In a preferred embodiment, the programmable control module includes an MCU module, a digital-to-analog converter, a GPIO expansion chip, and a Darlington transistor. The I2C_SCL and I2C_SDA pins of the MCU module are connected to the corresponding pins of the digital-to-analog converter and the GPIO expansion chip. The DAC_ELOAD_SET pin of the digital-to-analog converter is connected to the non-inverting input of the operational amplifier. The Darlington transistor is connected to the GPIO expansion chip and the relay module. Attached Figure Description
[0010] Figure 1 This is a system block diagram of this utility model;
[0011] Figure 2 This is the circuit schematic diagram of the first part of the electronic load module;
[0012] Figure 3 This is the circuit schematic diagram of the second part of the electronic load module;
[0013] Figure 4 This is the circuit schematic diagram of the programmable control module. Detailed Implementation
[0014] like Figures 1 to 2 As shown, in this embodiment, the present invention includes a programmable control module 1 and an electronic load module 2. The programmable control module 1 is connected to the electronic load module 2. The electronic load module 2 includes an operational amplifier U5, an instrumentation amplifier U7, a multiplexer U6, a resistor module 3, and a relay module 4. The non-inverting input terminal of the operational amplifier U5 is connected to the programmable control module 1. The inverting input terminal and the output terminal of the operational amplifier U5 are both connected to the output terminal of the instrumentation amplifier U7. The input terminal of the instrumentation amplifier U7 is connected to the multiplexer U6. The multiplexer U6 is connected to the relay module 4 via the resistor module 3.
[0015] The operational amplifier U5 is model OPA2196IDGKT, the instrumentation amplifier U7 is model INA826AIDGK, and the multiplexer U6 is model ADG1409YRUZ.
[0016] like Figures 1 to 2 As shown, in this embodiment, the electronic load module 2 further includes a MOS transistor Q1, the gate of which is connected to the output terminal of the operational amplifier U5, and the source of which is connected to the relay module 4.
[0017] like Figures 1 to 3 As shown, in this embodiment, the resistor module 3 includes a first sampling resistor R27, a second sampling resistor R31, a third sampling resistor R35, and a fourth sampling resistor R44. The relay module 4 includes a first relay K1, a second relay K2, a third relay K3, a fourth relay K4, and a fifth relay K5. The S1A and S1B terminals of the multiplexer U6 are both connected to the first relay K1 via the first sampling resistor R27. The S2A and S2B terminals of the multiplexer U6 are both connected to the second relay K2 via the second sampling resistor R31. The S3A and S3B terminals of the multiplexer U6 are both connected to the third relay K3 via the third sampling resistor R35. The S4A and S4B terminals of the multiplexer U6 are both connected to the fourth relay K4 and the fifth relay K5 via the fourth sampling resistor R44.
[0018] The non-inverting input of operational amplifier U5 is the DAC output voltage Vset, where Vset = V. Instrumentation amplifier U7 is an instrumentation operational amplifier with a gain of G = 49.4 / 5.49 + 1 ≈ 10 and V = 10(Va - Vb). Multiplexer U6 is a single-chip iCMOS analog multiplexer with four built-in differential channels. Multiplexer U6 switches one of the four differential inputs to a common differential output based on the address determined by the two binary address lines A0 and A1. Vpx = Va, Vnx = Vb. When the first relay K1 is closed, the address lines A1 and A0 of the multiplexer U6 are set to 00, and the 1uA range is turned on. Therefore, the Eload setting current Iset = (Vp1 - Vn1) / R27 = (Va - Vb) / R27 = Vset / 10R27. When the second relay K2 is closed, the address lines A1 and A0 of the multiplexer U6 are set to 01, and the 1mA range is turned on. Similarly, the Eload setting current Iset = Vset / 10R31. When the third relay K3 is closed, the address lines A1 and A0 of the multiplexer U6 are set to 10, and the 3A range is turned on. Similarly, the Eload setting current Iset = Vset / 10R35. When the fourth relay K4 and the fifth relay K5 are closed, the multiplexer U6... When address lines A1 and A0 are set to 11, the 10A range is turned on. Similarly, Eload sets the current Iset = Vset / 10R44.
[0019] like Figure 4 As shown, in this embodiment, the programmable control module 1 includes an MCU module U1, a digital-to-analog converter U2, a GPIO expansion chip U3, and a Darlington transistor U4. The I2C_SCL and I2C_SDA pins of the MCU module U1 are connected to the corresponding pins of the digital-to-analog converter U2 and the GPIO expansion chip U3. The DAC_ELOAD_SET pin of the digital-to-analog converter U2 is connected to the non-inverting input of the operational amplifier U5. The Darlington transistor U4 is connected to the GPIO expansion chip U3 and the relay module 4. The digital-to-analog converter U2 converts digital signals into analog voltage outputs via a configurable IIC bus. The GPIO expansion chip U3 expands its GPIO to up to 16 channels. The switching of the relay module 4 can be driven by controlling the Darlington transistor U4.
Claims
1. A wide-range electronic load device, characterized in that: It includes a programmable control module (1) and an electronic load module (2). The programmable control module (1) is connected to the electronic load module (2). The electronic load module (2) includes an operational amplifier (U5), an instrumentation amplifier (U7), a multiplexer (U6), a resistor module (3), and a relay module (4). The non-inverting input terminal of the operational amplifier (U5) is connected to the programmable control module (1). The inverting input terminal and the output terminal of the operational amplifier (U5) are both connected to the output terminal of the instrumentation amplifier (U7). The input terminal of the instrumentation amplifier (U7) is connected to the multiplexer (U6). The multiplexer (U6) is connected to the relay module (4) via the resistor module (3).
2. The wide-range electronic load device according to claim 1, characterized in that: The electronic load module (2) also includes a MOS transistor (Q1), the gate of which is connected to the output terminal of the operational amplifier (U5), and the source of which is connected to the relay module (4).
3. The wide-range electronic load device according to claim 2, characterized in that: The resistor module (3) includes a first sampling resistor (R27), a second sampling resistor (R31), a third sampling resistor (R35), and a fourth sampling resistor (R44). The relay module (4) includes a first relay (K1), a second relay (K2), a third relay (K3), a fourth relay (K4), and a fifth relay (K5). The S1A and S1B terminals of the multiplexer (U6) are connected to the first relay (K1) via the first sampling resistor (R27). The S2A and S2B terminals of the multiplexer (U6) are connected to the second relay (K2) via the second sampling resistor (R31). The S3A and S3B terminals of the multiplexer (U6) are connected to the third relay (K3) via the third sampling resistor (R35). The S4A and S4B terminals of the multiplexer (U6) are connected to the fourth relay (K4) and the fifth relay (K5) via the fourth sampling resistor (R44).
4. The wide-range electronic load device according to claim 1, characterized in that: The programmable control module (1) includes an MCU module (U1), a digital-to-analog converter (U2), a GPIO expansion chip (U3), and a Darlington transistor (U4). The I2C_SCL pin and I2C_SDA pin of the MCU module (U1) are connected to the corresponding pins of the digital-to-analog converter (U2) and the GPIO expansion chip (U3). The DAC_ELOAD_SET pin of the digital-to-analog converter (U2) is connected to the non-inverting input of the operational amplifier (U5). The Darlington transistor (U4) is connected to the GPIO expansion chip (U3) and the relay module (4).