USB load test fixture

Abstract

The utility model relates to a USB load test fixture. The USB load test fixture comprises a load circuit board and a test circuit board, the onboard USB interface, the first resistance circuit, the second resistance circuit, the third resistance circuit, the fourth resistance circuit and the fifth resistance circuit are arranged on the load circuit board, the first resistance circuit is used for simulating 100mA load current, the second resistance circuit is used for simulating 150mA load current, the third resistance circuit is used for simulating 500mA load current, the fourth resistance circuit is used for simulating 900mA load current, and the fifth resistance circuit is used for simulating 1500mA load current. The first jumper wire structure, the second jumper wire structure, the third jumper wire structure, the fourth jumper wire structure and the fifth jumper wire structure are controlled to be connected and disconnected by using jumper wire caps; one end of each resistance circuit is electrically connected with a power supply terminal of the onboard USB interface through the corresponding jumper structure, and the other end of each resistance circuit is grounded. According to the USB load test fixture provided by the utility model, the convenience is greatly improved when the USB load test of the industrial personal computer is carried out.

Description

Technical Field

[0001] The utility model relates to the technical field of electronic computers, in particular to a USB load test fixture. Background Art

[0002] USB (Universal Serial Bus) is a serial bus standard and also a technical specification for input / output interfaces. It is widely used in information communication products such as personal computers and mobile devices, and has been extended to other related fields such as photographic equipment, digital TVs (set-top boxes), and game consoles.

[0003] USB interface load testing mainly involves simulating different maximum standard load currents to evaluate the performance and stability of USB interfaces. This testing is achieved by using a dedicated test load circuit that can simulate a variety of different maximum standard load currents, thereby ensuring that the USB interface can withstand the expected load conditions in actual applications.

[0004] Currently, for USB load testing, most companies still use methods such as cement loads, slide rheostats, and electronic load meters for testing. Such fixtures have problems such as load resistance changes caused by heat generation, interference between two USB interfaces due to the large load volume, and insufficient load channels.

[0005] An industrial control computer is a general term for tools that use a bus structure to detect and control the production process, electromechanical equipment, and process equipment. The shape of an industrial control computer is generally square, and it is connected to electromechanical equipment through various interfaces, and can monitor and control the operating status of electromechanical equipment. As the number of external devices connected to the industrial control computer increases, the number of its USB interfaces also increases.

[0006] For an industrial control computer, if a traditional cement load is used for USB load testing, in addition to the lack of space caused by two USB interfaces, the length of the load usage time will also affect the temperature of the load, thereby causing changes in the load size and resulting in inaccurate testing. If an electronic load instrument is used, the channels may not be sufficient to meet the needs of simultaneous testing of multiple USB interfaces of the industrial control computer. Summary of the Invention

[0007] Therefore, the purpose of the utility model is to provide a USB load test fixture to facilitate the USB load testing of industrial control computers.

[0008] To achieve the above object, the present utility model provides a USB load test fixture, comprising: a load circuit board, an on-board USB interface provided on the load circuit board, a first resistor circuit for simulating a 100 mA load current, a second resistor circuit for simulating a 150 mA load current, a third resistor circuit for simulating a 500 mA load current, a fourth resistor circuit for simulating a 900 mA load current, and a fifth resistor circuit for simulating a 1500 mA load current, a first jumper structure, a second jumper structure, a third jumper structure, a fourth jumper structure, and a fifth jumper structure provided on the load circuit board and controlled by jumper caps for on / off, and jumper caps; one end of the first resistor circuit is electrically connected to the power terminal of the on-board USB interface via the first jumper structure, and the other end is grounded; one end of the second resistor circuit is electrically connected to the power terminal of the on-board USB interface via the second jumper structure, and the other end is grounded; one end of the third resistor circuit is electrically connected to the power terminal of the on-board USB interface via the third jumper structure, and the other end is grounded; one end of the fourth resistor circuit is electrically connected to the power terminal of the on-board USB interface via the fourth jumper structure, and the other end is grounded; one end of the fifth resistor circuit is electrically connected to the power terminal of the on-board USB interface via the fifth jumper structure, and the other end is grounded.

[0009] Wherein, it further includes a USB connecting wire, and USB connectors for connecting the USB interface to be tested and the on-board USB interface are respectively provided at both ends of the USB connecting wire.

[0010] Wherein, it further includes a filter capacitor provided on the load circuit board; one end of the filter capacitor is electrically connected to the power terminal of the on-board USB interface, and the other end is grounded.

[0011] Wherein, the first resistor circuit, the second resistor circuit, the third resistor circuit, the fourth resistor circuit, and / or the fifth resistor circuit are composed of precision resistors.

[0012] Wherein, the first resistor circuit, the second resistor circuit, the third resistor circuit, the fourth resistor circuit, and / or the fifth resistor circuit are respectively composed of a plurality of precision resistors connected in parallel.

[0013] Wherein, it further includes a sixth resistor circuit provided on the load circuit board for simulating a short circuit, and a sixth jumper structure provided on the load circuit board and controlled by a jumper cap for on / off; one end of the sixth resistor circuit is electrically connected to the power terminal of the on-board USB interface via the sixth jumper structure, and the other end is grounded.

[0014] Wherein, the sixth resistor circuit is a 0.05-ohm precision resistor.

[0015] Wherein, the on-board USB interface is a USB female head.

[0016] Among them, the USB connectors at both ends of the USB connection cable are male USB connectors.

[0017] Among them, the first resistor circuit is composed of two 100-ohm precision resistors in parallel, the second resistor circuit is composed of three 10-ohm precision resistors in parallel, the third resistor circuit is composed of six 60.4-ohm precision resistors in parallel, the fourth resistor circuit is composed of seven 39-ohm precision resistors in parallel, and the fifth resistor circuit is composed of nine 30-ohm precision resistors in parallel.

[0018] In summary, for the USB load test fixture of the present utility model, the convenience is greatly improved when performing the USB load test on the industrial control computer. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The following will, by way of a detailed description of the specific embodiments of the present utility model in conjunction with the drawings, make the technical solutions and other beneficial effects of the present utility model obvious. In the drawings,

[0020] Figure 1 is a schematic diagram of the female USB interface to be tested in a preferred embodiment of the USB load test fixture of the present utility model;

[0021] Figure 2 is a schematic diagram of the USB connection cable in a preferred embodiment of the USB load test fixture of the present utility model;

[0022] Figure 3 is a schematic diagram of the layout structure of the load circuit board in a preferred embodiment of the USB load test fixture of the present utility model;

[0023] Figure 4 is a circuit structure diagram of a preferred embodiment of the USB load test fixture of the present utility model. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0024] Refer to Figure 3 and Figure 4 , Figure 3 is a schematic diagram of the layout structure of the load circuit board in a preferred embodiment of the USB load test fixture of the present utility model, Figure 4 and this is the circuit structure diagram of this preferred embodiment. The USB load test fixture provided by the present utility model mainly includes: a load circuit board 30, an on-board USB interface 31 provided on the load circuit board 30, and test circuits respectively composed of resistors 32 of various sizes, including a first resistor circuit for simulating a 100 mA load current, a second resistor circuit for simulating a 150 mA load current, a third resistor circuit for simulating a 500 mA load current, a fourth resistor circuit for simulating a 900 mA load current, and a fifth resistor circuit for simulating a 1500 mA load current. In this preferred embodiment, each resistor circuit is marked with the corresponding load current on the load circuit board 30.

[0025] On the load circuit board 30, corresponding jumper structures 33 for controlling on / off using jumper caps are respectively provided for each resistor circuit, including a first jumper structure, a second jumper structure, a third jumper structure, a fourth jumper structure, and a fifth jumper structure. When performing a USB load test, a jumper cap is used to select and connect a certain resistor circuit.

[0026] One end of the first resistor circuit is electrically connected to the power terminal of the on-board USB interface 31 via the first jumper structure, and the other end is grounded; one end of the second resistor circuit is electrically connected to the power terminal of the on-board USB interface 31 via the second jumper structure, and the other end is grounded; one end of the third resistor circuit is electrically connected to the power terminal of the on-board USB interface 31 via the third jumper structure, and the other end is grounded; one end of the fourth resistor circuit is electrically connected to the power terminal of the on-board USB interface 31 via the fourth jumper structure, and the other end is grounded; one end of the fifth resistor circuit is electrically connected to the power terminal of the on-board USB interface 31 via the fifth jumper structure, and the other end is grounded.

[0027] In this preferred embodiment, a sixth resistor circuit for simulating a short circuit (Short) is further provided on the load circuit board 30, and a sixth jumper structure 35 for controlling on / off using a jumper cap is provided on the load circuit board 30; one end of the sixth resistor circuit is electrically connected to the power terminal of the on-board USB interface 31 via the sixth jumper structure 35, and the other end is grounded. The sixth resistor circuit can use a 0.05-ohm precision resistor.

[0028] In this preferred embodiment, a filter capacitor 34 is further provided on the load circuit board 30; one end of the filter capacitor 34 is electrically connected to the power terminal of the on-board USB interface 31, and the other end is grounded. The specific specification of the filter capacitor 34 can be selected as 22 μF / 16V.

[0029] See Figure 1 and Figure 2 , Figure 1 is a schematic diagram of the female head of the USB interface to be tested in a preferred embodiment of the USB load test fixture of the present invention. Figure 2 This is a schematic diagram of the USB connection cable in this preferred embodiment. The USB load test fixture of the present invention further includes a USB connection cable 20. Since in this preferred embodiment, the USB interface 10 to be tested is a female head and the on-board USB interface 31 is also a female head, USB connector male heads for connecting the USB interface 10 to be tested and the on-board USB interface 31 are respectively provided at both ends of the USB connection cable 20. The USB connectors on the USB connection cable 20 are small in size and there is no interference problem between the two USB ports of the electronic device to be tested.

[0030] Among them, the first resistance circuit, the second resistance circuit, the third resistance circuit, the fourth resistance circuit, and / or the fifth resistance circuit are composed of precision resistors. By using precision resistors, the test precision can be improved, making the test more accurate.

[0031] Among them, the first resistance circuit, the second resistance circuit, the third resistance circuit, the fourth resistance circuit, and / or the fifth resistance circuit are respectively composed of multiple precision resistors connected in parallel. Considering that the current-carrying capacity of a single small-volume precision resistor may be insufficient, while a large-volume resistor will occupy too much space, the present utility model uses the method of connecting resistors in parallel to solve this problem.

[0032] The USB load test fixture of the present utility model can be used immediately after being plugged in. The load size can be selected with a jumper cap, and there are five gears of 100 mA, 150 mA, 500 mA, 900 mA, and 1500 mA for selection. Generally, a 2.0 USB will select 500 mA, and a 3.0 USB will select 900 mA. The load size depends on the corresponding test standards of different manufacturers. In addition to the load size, the present utility model also comes with a short circuit (Short) test function.

[0033] When using the USB load test fixture of the present utility model for testing, taking the measurement of the static load of the USB interface of an industrial control computer as an example: Connect the USB interface of the tested industrial control computer after startup to the on-board USB interface 31 on the load circuit board 30 through the USB connection line 20, and select the jumper cap on the load circuit board 30 to an appropriate load size. At this time, use a tool for measuring voltage (such as a multimeter) to measure the voltage of the USB interface of the industrial control computer, and then the voltage drop caused by the load of this USB interface can be measured to see if it meets the test standard.

[0034] Working principle:

[0035] After the tested industrial control computer is connected to the load circuit board 30, the function of the jumper cap is to form a loop for the corresponding load resistance circuit. At this time, it is equivalent to adding a load to the tested USB interface, thus completing the load test. Regarding the selection of the load size, in this preferred embodiment, the load resistors of the present utility model will use precision resistors connected in parallel. According to Ohm's law I = U / R, assuming that the known voltage U = 5V, then controlling the load resistor R can obtain the load current I.

[0036] Taking 500 mA as an example, according to the transformation of I = U / R, we can get R = U / I = 5 V / 0.5 A = 10 Ω. Therefore, the parallel equivalent resistance needs to be controlled at 10 Ω. At the same time, considering that the current-carrying capacity of a single small-volume precision resistor may be insufficient, while a large-volume resistor will occupy too much space, here 6 resistors with a resistance of 60.4 Ω are used in parallel, and the parallel equivalent resistance is 10.066 Ω, meeting the design requirements. The operating temperature range is from 0 to 85 degrees Celsius.

[0037] In this preferred embodiment, the first resistor circuit is composed of two 100-Ω precision resistors in parallel, the second resistor circuit is composed of three 10-Ω precision resistors in parallel, the fourth resistor circuit is composed of seven 39-Ω precision resistors in parallel, and the fifth resistor circuit is composed of nine 30-Ω precision resistors in parallel.

[0038] The USB load test fixture of the present invention has a small-sized connector of the USB cable 20, which can be plugged and used immediately. On the load circuit board 30, a jumper cap can be used to select the load size, and there are six gears available for selection, namely Short, 100 mA, 150 mA, 500 mA, 900 mA, and 1500 mA, with sufficient load channels. It has the following advantages: The USB connector of the USB cable 20 has a small size, and there is no interference problem between the two USB ports on the electronic device to be tested; The present invention uses precision resistors as the load to improve the test precision, making the test more accurate; The convenience of load testing is greatly improved; The USB load test fixture of the present invention can be used in combination with USB male and female connectors. With the USB cable 20 as the proximal connector, it is convenient for measurement and easy to plug and unplug; The USB interface load gears are sufficient, meeting the characteristics of multiple USB interfaces to be measured on the industrial control computer.

[0039] The USB load test fixture of the present invention is applied to the load test of USB ports. Although it is mainly used in industrial control computers, it is not limited to industrial control computers and is also applicable to USB interfaces on other motherboards, circuit boards, or electronic devices.

[0040] In summary, the convenience of the USB load test fixture of the present invention is greatly improved when performing the USB load test of an industrial control computer.

[0041] As mentioned above, for those of ordinary skill in the art, various corresponding changes and deformations can be made according to the technical solutions and concepts of the present invention, and all such changes and deformations should fall within the protection scope of the appended claims of the present invention.

Claims

1. A USB load test fixture, characterized in that: include: A load circuit board, an onboard USB interface arranged on the load circuit board, a first resistance circuit for simulating a 100mA load current, a second resistance circuit for simulating a 150mA load current, a third resistance circuit for simulating a 500mA load current, a fourth resistance circuit for simulating a 900mA load current, and a fifth resistance circuit for simulating a 1500mA load current, a first jumper structure, a second jumper structure, a third jumper structure, a fourth jumper structure, and a fifth jumper structure arranged on the load circuit board and controlled on and off by a jumper cap, and a jumper cap; the first resistance circuit One end of the circuit is electrically connected to the power terminal of the onboard USB interface via the first jumper structure, and the other end is grounded; one end of the second resistance circuit is electrically connected to the power terminal of the onboard USB interface via the second jumper structure, and the other end is grounded; one end of the third resistance circuit is electrically connected to the power terminal of the onboard USB interface via the third jumper structure, and the other end is grounded; one end of the fourth resistance circuit is electrically connected to the power terminal of the onboard USB interface via the fourth jumper structure, and the other end is grounded; one end of the fifth resistance circuit is electrically connected to the power terminal of the onboard USB interface via the fifth jumper structure, and the other end is grounded.

2. The USB load test fixture as claimed in claim 1, characterized in that: It also includes a USB connecting line, and both ends of the USB connecting line are respectively provided with USB connectors for connecting the USB interface to be tested and the onboard USB interface.

3. The USB load test fixture as claimed in claim 1, characterized in that: It also includes a filter capacitor arranged on the load circuit board; one end of the filter capacitor is electrically connected to the power terminal of the onboard USB interface, and the other end is grounded.

4. The USB load test fixture as claimed in claim 1, characterized in that: The first resistance circuit, the second resistance circuit, the third resistance circuit, the fourth resistance circuit and / or the fifth resistance circuit are composed of precision resistors.

5. The USB load test fixture as claimed in claim 1, characterized in that: The first resistance circuit, the second resistance circuit, the third resistance circuit, the fourth resistance circuit and / or the fifth resistance circuit are respectively composed of a plurality of precision resistors connected in parallel.

6. The USB load test fixture as claimed in claim 1, characterized in that: It also includes a sixth resistor circuit arranged on the load circuit board for simulating a short circuit, and a sixth jumper structure arranged on the load circuit board and controlled on and off by a jumper cap; one end of the sixth resistor circuit is electrically connected to the power terminal of the onboard USB interface via the sixth jumper structure, and the other end is grounded.

7. The USB load test fixture as claimed in claim 6, characterized in that: The sixth resistor circuit is a 0.05 ohm precision resistor.

8. The USB load test fixture as claimed in claim 1, characterized in that: The onboard USB interface is a USB female connector.

9. The USB load test fixture as claimed in claim 2, characterized in that: The USB connectors at both ends of the USB connecting line are USB male connectors.

10. The USB load test fixture as claimed in claim 5, characterized in that: The first resistance circuit is composed of two 100 ohm precision resistors in parallel, the second resistance circuit is composed of three 10 ohm precision resistors in parallel, the third resistance circuit is composed of six 60.4 ohm precision resistors in parallel, the fourth resistance circuit is composed of seven 39 ohm precision resistors in parallel, and the fifth resistance circuit is composed of nine 30 ohm precision resistors in parallel.

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