Control circuit, protection control method, test equipment and test system

Abstract

The invention discloses a control circuit, a protection control method, a test device and a test system, and relates to the technical field of power supply test, the control circuit comprises a test end, a current sampling unit and a current adjusting unit, the current sampling unit is connected with the test end, collects the output current of a tested device, and outputs a current sampling signal; the output end of the current adjusting unit is connected with the test end; the regulation control unit is connected with the controlled end of the current regulation unit; when the test equipment is in a constant-voltage mode and the current value of the current sampling signal is not within a preset current threshold range, the adjustment control unit controls the current adjustment unit to adjust the output current of the tested equipment, so that the test equipment works in a constant-current mode, and the output current flowing through the tested equipment is limited within the preset current threshold range. The invention aims to limit the output current of the tested equipment and prevent the tested equipment and the test equipment from being damaged by large current, so that the reliability and the safety of the test process of the power supply device are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of power supply testing, and in particular to a control circuit, a protection control method, a testing device and a testing system. Background Art

[0002] With the rapid development of electronic technology, various electronic devices are being used more and more widely. These electronic devices have higher and higher requirements for power supply. They not only need stable and reliable power supply, but also need to adapt to load changes in different working environments. Therefore, it is particularly important to perform performance testing on the power supply device of electronic equipment. For example, when testing, it is expected to use the constant voltage mode of the electronic load as a test device to verify the constant current performance of the power supply device. If a traditional electronic load is used, the electronic load will trigger the protection function and terminate the test when the maximum allowable current and rated power are reached. Or when the constant current response inside the power supply device is slow, the instantaneous current of the electronic load in the constant voltage mode will be too large, damaging the power supply device and the electronic load. Summary of the invention

[0003] The main purpose of the present invention is to propose a control circuit, a protection control method, a test device and a test system, which are intended to limit the output current of the device under test and prevent large currents from causing damage to the device under test and the test device, thereby improving the reliability and safety of the power supply device test process.

[0004] To achieve the above object, the present invention provides a control circuit, the control circuit comprising:

[0005] Test terminal, used to connect to the power supply terminal of the test equipment;

[0006] A current sampling unit, electrically connected to the test terminal, for collecting the output current of the device under test and outputting a corresponding current sampling signal;

[0007] A current regulating unit, wherein an output end of the current regulating unit is connected to the test end;

[0008] A regulating control unit connected to the controlled end of the current regulating unit;

[0009] The regulation control unit is used to control the current regulation unit to regulate the output current of the device under test when the test device is in a constant voltage mode and the current value of the current sampling signal is not within a preset current threshold range, so that the test device operates in a constant current mode and the output current flowing through the device under test is limited to within a preset current threshold range.

[0010] In one embodiment, the control circuit further includes:

[0011] A voltage sampling unit, electrically connected to the test terminal, for collecting the output voltage of the device under test and outputting a corresponding voltage sampling signal to the regulation control unit;

[0012] A voltage regulating unit, wherein a controlled end of the voltage regulating unit is electrically connected to the regulating control unit;

[0013] The regulation control unit is used to control the voltage regulation unit to adjust the output voltage of the device under test when the voltage value of the voltage sampling signal is not within the preset voltage threshold range, so that the test device operates in a constant voltage mode and limits the output voltage of the device under test to within the preset voltage threshold range.

[0014] In one embodiment, the test end includes a positive terminal and a negative terminal, and the current regulating unit and the voltage regulating unit are arranged in series between the positive terminal and the negative terminal.

[0015] In one embodiment, the current regulating unit includes:

[0016] a first adjustable resistance unit, wherein an output end of the first adjustable resistance unit is electrically connected to the test end, and a controlled end of the first adjustable resistance unit is electrically connected to the adjustment control unit;

[0017] The regulation control unit is used to control the first adjustable resistance unit to adjust the resistance value of the first adjustable resistance unit when the current value of the current sampling signal is not within a preset current threshold range when the test device is in a constant voltage mode, so that the test device operates in a constant current mode and limits the output current flowing through the device under test to within a preset current threshold range.

[0018] In one embodiment, the first adjustable resistance unit includes:

[0019] a first transistor circuit, wherein the first transistor circuit is electrically connected to the test end, and a controlled end of the first transistor circuit is electrically connected to the regulation control unit;

[0020] The regulating control unit is specifically used to control the conduction degree of the first transistor circuit so as to limit the output current flowing through the device under test to within a preset current threshold range.

[0021] In one embodiment, the voltage regulating unit includes:

[0022] a second adjustable resistance unit, wherein the second adjustable resistance unit is electrically connected to the test end, and a controlled end of the second adjustable resistance unit is electrically connected to the adjustment control unit;

[0023] The regulating control unit is used to control the second adjustable resistance unit to adjust the resistance value of the second adjustable resistance unit when the current value of the current sampling signal is within a preset current threshold range when the test device is in a constant voltage mode, so that the test device works in a constant voltage mode and the output voltage of the device under test is limited within a preset voltage threshold range;

[0024] And, it is used to control the second adjustable resistance unit to adjust the resistance value of the second adjustable resistance unit when the voltage value of the voltage sampling signal is not within a preset voltage threshold range when the test device is in a constant voltage mode, so that the test device operates in a constant voltage mode and limits the output voltage of the device under test to within a preset voltage threshold range.

[0025] In one embodiment, the second adjustable resistance unit includes:

[0026] a second transistor circuit, wherein the second transistor circuit is electrically connected to the test end, and a controlled end of the second transistor circuit is electrically connected to the regulation control unit;

[0027] The regulating control unit is specifically used to regulate the conduction degree of the second transistor circuit so as to limit the output voltage of the device under test within a preset voltage threshold range.

[0028] In one embodiment, the regulation control unit comprises:

[0029] A voltage control unit, wherein an input end of the voltage control unit is electrically connected to an output end of the voltage sampling unit, and a control end of the voltage control unit is electrically connected to the voltage regulating unit;

[0030] The voltage control unit is used to control the voltage adjustment unit to adjust the output voltage of the device under test when the voltage value of the voltage sampling signal is not within the preset voltage threshold range, so that the test device works in a constant voltage mode and limits the voltage of the device under test to within the preset voltage threshold range;

[0031] A current control unit, wherein an input end of the current control unit is electrically connected to an output end of the current sampling unit, and a control end of the current control unit is electrically connected to the current regulating unit;

[0032] The current control unit is used to control the current regulation unit to adjust the output current of the device under test when the current value of the current sampling signal is not within a preset current threshold range, so that the test device operates in a constant current mode and limits the output current flowing through the device under test to within a preset current threshold range.

[0033] The present invention further provides a protection control method, the protection control method using any one of the control circuits described above, the protection control method comprising:

[0034] Obtain the working mode of the test equipment and the output current of the device under test;

[0035] When the test device is in constant voltage mode, when the current value of the output current is not within a preset current threshold range, the test device is controlled to operate in constant current mode to limit the output current of the device under test within a preset current threshold range.

[0036] The present invention further provides a testing device, the testing device comprising any one of the control circuits described above, or,

[0037] A control device, the control device comprising: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the computer program is configured to implement the steps of the protection control method described above.

[0038] The present invention further provides a test system, which includes the control circuit described in any one of the above items, or the test device described in the above items, and a device under test; the device under test is electrically connected to the test device.

[0039] The present invention proposes a control circuit, which includes a test terminal for connecting to a device under test, a current sampling unit and a current regulating unit, wherein the current sampling unit is electrically connected to the test terminal and is used to collect the output current of the device under test and output a corresponding current sampling signal; the output terminal of the current regulating unit is connected to the test terminal; a regulating control unit is connected to the controlled terminal of the current regulating unit; and the regulating control unit is used to control the current regulating unit to regulate the output current of the device under test when the current value of the current sampling signal is not within a preset current threshold range when the test device is in a constant voltage mode, so that the test device operates in a constant current mode and the output current flowing through the device under test is limited within a preset current threshold range.

[0040] In actual applications, the regulating control unit will control the current regulating unit to adjust the output current of the device under test according to the current sampling signal output by the current sampling unit, so that when the output current of the device under test is not within the preset current threshold range, for example, when the output current is greater than the constant current of the set test device, the test device is operated in a constant current mode, and the output current flowing through the device under test is limited to within the preset current threshold range. In this way, when the power supply device (device under test) of the electronic device is subjected to performance testing, when the test device is in a constant voltage mode, it can be ensured that the current will not exceed the preset current threshold range when the test terminal is connected to the device under test, thereby improving the phenomenon of large current causing damage to the device under test and the test device, and effectively protecting the device under test and the test device, thereby improving the reliability of the power supply device test process. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0042] Figure 1 A schematic diagram of a module of an embodiment of a control circuit of the present invention;

[0043] Figure 2 A module schematic diagram of another embodiment of the control circuit of the present invention;

[0044] Figure 3 A module schematic diagram of another embodiment of the control circuit of the present invention;

[0045] Figure 4 It is a module schematic diagram of an embodiment of a conventional control circuit;

[0046] Figure 5 A module schematic diagram of another embodiment of the control circuit of the present invention;

[0047] Figure 6 A module schematic diagram of another embodiment of the control circuit of the present invention;

[0048] Figure 7 FIG. 4 is a module diagram of another embodiment of the control circuit of the present invention.

[0049] Description of Figure Numbers:

[0050] 10. Test end; 20. Current sampling unit; 30. Current regulating unit; 40. Regulation control circuit; 50. Voltage sampling unit; 60. Voltage regulating unit; 11. Positive end; 12. Negative end; 41. Current control unit; 42. Voltage control unit.

[0051] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0052] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0053] It should be noted that, in this article, step codes such as S100, S200, etc. are used for the purpose of expressing the corresponding content more clearly and concisely, and do not constitute a substantial limitation on the sequence. When implementing the step, those skilled in the art may execute S200 first and then S100, etc., but these should all be within the scope of protection of this application.

[0054] With the rapid development of electronic technology, various electronic devices are being used more and more widely. These electronic devices have higher and higher requirements for power supply. They not only need stable and reliable power supply, but also need to adapt to load changes in different working environments. Therefore, it is particularly important to perform performance testing on the power supply device of electronic equipment. For example, when testing, it is expected to use the constant voltage mode of the electronic load as a test device to verify the constant current performance of the power supply device. If a traditional electronic load is used, the electronic load will trigger the protection function and terminate the test when the maximum allowable current and rated power are reached. Or when the constant current response inside the power supply device is slow, the instantaneous current of the electronic load in the constant voltage mode will be too large, damaging the power supply device and the electronic load.

[0055] It is understandable that verifying the constant current function of the power supply device (device under test) when the electronic load is in constant voltage mode (CV mode) is mainly to simulate the load conditions in actual applications and ensure that the device under test can stably provide a constant current output under different load conditions. The load usually maintains a relatively stable voltage, while the current demand may vary. By setting the electronic load to constant voltage mode, this actual load condition can be simulated, that is, the load maintains a constant voltage, and the current is adjusted according to the output capacity of the device under test. That is, by setting the electronic load to constant voltage mode and gradually changing the load resistance, it is possible to observe whether the device under test can maintain a constant current output. If the device under test has good constant current performance, it should be able to maintain the set current value under different load conditions. Therefore, by setting the electronic load to constant voltage mode and detecting and adjusting the output current of the device under test, the constant current performance of the device under test can be effectively verified.

[0056] The present invention provides a control circuit, referring to Figure 1 , the control circuit comprises:

[0057] Test terminal 10, used to connect to the power supply terminal of the device under test;

[0058] A current sampling unit 20, electrically connected to the test terminal 10, for collecting the output current of the device under test and outputting a corresponding current sampling signal;

[0059] A current regulating unit 30, wherein an output end of the current regulating unit 30 is connected to the test end 10;

[0060] A regulating control unit connected to the controlled end of the current regulating unit 30;

[0061] The regulation control unit is used to control the current regulation unit 30 to adjust the output current of the device under test when the test device is in a constant voltage mode and the current value of the current sampling signal is not within a preset current threshold range, so that the test device operates in a constant current mode and limits the output current flowing through the device under test to within a preset current threshold range.

[0062] In this embodiment, the current sampling unit 20 can be implemented by a Hall effect sensor, a current detection resistor, a dedicated current detection chip, etc. The regulating control unit can be implemented by a main controller, such as an MCU, a DSP (Digital Signal Process), an FPGA (Field Programmable Gate Array), a PLC, a SOC (System On Chip), etc. The current regulating unit 30 can be implemented by an adjustable resistor (such as a potentiometer, a transistor unit, etc.), a linear regulator, etc. The power supply device includes a power supply, a battery, a charging chip, etc.

[0063] It should be noted that the electronic load is a test device used to simulate actual load conditions. It can operate in different working modes (such as constant voltage mode CV, constant current mode CC, constant resistance mode CR, constant power mode CP). The main functions of the electronic load include: simulating load conditions in actual applications to test the performance of power supply devices such as power supplies, batteries and charging chips under different loads. By quickly changing the load conditions, the dynamic response capability of the device under test can be tested. The protection function of the device under test under abnormal conditions such as overload and short circuit can also be verified to evaluate the efficiency and stability of the device under test. Therefore, the electronic load is an important tool for testing power supplies, batteries and charging chips to ensure their stability and safety under various conditions. The device under test is equivalent to a power supply device that provides power to the electronic load. The output voltage of the power supply end is Vout. Assuming that the equivalent resistance of the electronic load is Rload, the electronic load can control the output current or voltage of the device under test by adjusting its own equivalent resistance when testing the device under test.

[0064] Specifically, the power supply terminal of the device under test (i.e., the power supply device) is connected to the test terminal 10 of the control circuit, and the electronic load is set to a constant voltage mode, and a constant preset voltage threshold (e.g., 5V) is set. In the constant voltage mode, the output voltage of the device under test should be a first voltage, so that the electronic load will try to maintain this voltage unchanged, and by adjusting the equivalent resistance of the electronic load itself, the device under test can stably output a voltage of 5V. At the same time, a preset current threshold range (e.g., 0A to 1.1A) is set to ensure that when the output current of the device under test is too large during the test process, the electronic load only allows current in this range to pass. During the test, the voltage sampling unit 50 collects the output voltage of the device under test output to the test terminal 10 through the power supply terminal, and outputs the corresponding voltage sampling signal. The regulating control unit controls the working state of the voltage regulating unit 60 according to the voltage sampling signal, so that it adjusts the output current of the device under test. For example, if Vout is higher than the first voltage: the voltage control unit 42 controls the voltage regulating unit 60 to reduce the equivalent resistance Rload of the electronic load. It can be known from Ohm's law Vout=Iout×Rload that when the equivalent resistance Rload decreases, the output current Iout of the device under test will increase. However, due to the existence of the internal resistance of the device under test, the increased current will produce a greater voltage drop on the internal resistance, which causes the output voltage Vout to decrease until the output voltage Vout of the device under test is within the preset voltage threshold range. In addition, the control circuit of the present invention collects the output current of the device under test by the current sampling unit 20 and outputs the corresponding current sampling signal. The regulating control unit controls the working state of the current regulating unit 30 according to the current sampling signal so that it adjusts the output current of the device under test. For example, the regulating control unit receives the current sampling signal and determines whether the current value of the current sampling signal is within the preset current threshold range. If the current value is not within the preset range, the regulating control unit will adjust the output current of the device under test by controlling the current regulating unit 30 to return it to the preset range, thereby improving the problem that the output current of the device under test is too large, causing the electronic load or the device under test itself to overheat or be damaged. If the output current Iout of the device under test is greater than the preset current threshold range, the current control unit 41 can control the current regulating unit 30 to increase the equivalent resistance Rload of the electronic load. It can be known from Ohm's law Vout=Iout×Rload that increasing the equivalent resistance Rload will cause the output current Iout to decrease, thereby reducing the output current of the device under test until Iout drops within the preset current threshold range. Similarly, if Iout is less than the preset current threshold range, the current control unit 41 will control the current regulation unit 30 to reduce the equivalent resistance of the electronic load, thereby increasing the output current of the device under test, until the output current Iout drops within the preset current threshold range, so that the electronic load operates in a constant current mode.Even if the electronic load used as the test equipment is in constant voltage mode, it can ensure that the output current of the device under test remains within a safe range, thereby achieving constant current performance testing. Among them, the preset current threshold range is set in advance by the R&D personnel, and the preset current threshold range can be adjusted according to different test requirements to adapt to a variety of test scenarios.

[0065] In actual applications, the constant current function of the electronic load is added in the constant voltage mode. When the output current of the device under test is greater than the constant current set for the electronic load, the electronic load can be controlled to work in the constant current mode. When the output current of the device under test is less than the constant current of the electronic load, the electronic load is controlled to work in the constant voltage mode. The current value is determined by the device under test, which reduces the risk of damage to the electronic load or the device under test and possible harm to personnel. Therefore, when the power supply device (device under test) of the electronic device is subjected to performance testing, when the test device is in the constant voltage mode, it can ensure that the current does not exceed the preset current threshold range when the test terminal 10 is connected to the device under test, thereby improving the phenomenon that large currents damage the device under test and the test device, and effectively protecting the device under test and the test device, thereby improving the reliability of the power supply device test process.

[0066] In one embodiment, reference Figure 2 , the control circuit further includes:

[0067] A voltage sampling unit 50, electrically connected to the test terminal 10, for collecting the output voltage of the device under test and outputting a corresponding voltage sampling signal to the regulation control unit;

[0068] A voltage regulating unit 60, wherein a controlled end of the voltage regulating unit 60 is electrically connected to the regulating control unit;

[0069] The regulation control unit is used to control the voltage regulation unit 60 to adjust the output voltage of the device under test when the voltage value of the voltage sampling signal is not within the preset voltage threshold range, so that the test device operates in a constant voltage mode and limits the output voltage of the device under test to within the preset voltage threshold range.

[0070] In this embodiment, the voltage sampling unit 50 can be implemented by a voltage divider circuit composed of at least two resistors, a voltage sensor, etc., and the voltage regulating unit 60 can be implemented by an adjustable resistor (such as a potentiometer, a transistor unit, etc.), a linear regulator, etc. The preset voltage threshold range is set in advance by the R&D personnel.

[0071] Specifically, the device under test (such as a power supply device) is connected to the test terminal 10 of the control circuit. The electronic load is set to a constant voltage mode and a constant voltage value (such as 5V) is set. A preset voltage threshold range (such as 0V to 5V) is set to ensure that the output voltage of the device under test is within the preset voltage threshold range during the test. And a preset current threshold range (such as 0A to 5A) is set to ensure that the output current of the device under test is within the preset current threshold range during the test. The device under test provides voltage to the electronic load. The voltage sampling unit 50 collects the output voltage of the device under test in real time and sends the voltage sampling signal to the adjustment control unit. The current sampling unit 20 collects the output current of the device under test in real time and sends the current sampling signal to the adjustment control unit. The adjustment control unit determines whether the voltage value is within the preset voltage threshold range according to the voltage sampling signal, and determines whether the current value is within the preset current threshold range according to the current sampling signal. For example, even if the device under test can provide a 10V voltage, but the maximum voltage value allowed by the control circuit of the present invention is 5V, the adjustment control unit will control the voltage adjustment unit 60 to reduce the output voltage of the device under test. If the device under test can provide an output current of 10A, the control circuit only allows a current of 5A to pass through, and the regulation control unit will control the current regulation unit 30 to reduce the output current of the device under test.

[0072] The voltage and current are monitored and adjusted dynamically in real time by the voltage sampling unit 50 and the current sampling unit 20, thereby avoiding equipment damage caused by excessive voltage or current, ensuring that the voltage and current values ​​during the test are always within the corresponding preset range, effectively verifying the constant current performance of the device under test, and ensuring the safety and accuracy of the test process.

[0073] It is understandable that when using a traditional electronic load, the electronic load will not set a constant current when working in the constant voltage mode. It will only trigger the protection function when the output current or output power of the device under test exceeds the maximum current and maximum power, causing the test to stop. And when the constant voltage mode of the electronic load is not clear, a discharge test on the battery (a type of device under test) will cause the battery to short-circuit directly, burn, and cause personal injury. In addition, when the charging voltage and charging current are tested on the charging chip (a type of device under test), because some charging chips have a relatively slow internal constant current response, the instantaneous current of the electronic load in the constant voltage mode will be very large, causing damage to the charging chip, or triggering the current protection or power protection of the electronic load, resulting in the inability to continue testing. In addition, in the existing scheme, there will be a transition period when controlling the electronic load to switch between constant voltage and constant current modes, causing instability.

[0074] Therefore, in another embodiment, the test end 10 includes a positive terminal 11 and a negative terminal 12 , and the current regulating unit 30 and the voltage regulating unit 60 are arranged in series between the positive terminal 11 and the negative terminal 12 .

[0075] The regulating control unit comprises:

[0076] A voltage control unit 42, wherein an input end of the voltage control unit 42 is electrically connected to an output end of the voltage sampling unit 50, and a control end of the voltage control unit 42 is electrically connected to the voltage regulating unit 60;

[0077] The voltage control unit 42 is used to control the voltage adjustment unit 60 to adjust the output voltage of the device under test when the voltage value of the voltage sampling signal is not within the preset voltage threshold range, so that the test device works in a constant voltage mode and limits the voltage of the device under test to within the preset voltage threshold range;

[0078] A current control unit 41, wherein an input end of the current control unit 41 is electrically connected to an output end of the current sampling unit 20, and a control end of the current control unit 41 is electrically connected to the current regulating unit 30;

[0079] The current control unit 41 is used to control the current regulating unit 30 to adjust the output current of the device under test when the current value of the current sampling signal is not within the preset current threshold range, so that the test device operates in a constant current mode and limits the current flowing through the device under test to within the preset current threshold range.

[0080] In this embodiment, both the voltage control unit 42 and the current control unit 41 can be implemented by the above-mentioned main controller.

[0081] refer to Figure 3 , the first end of the voltage regulating unit 60 is connected to the positive terminal 11, the second end of the voltage regulating unit 60 is electrically connected to the first end of the current sampling unit 20, the second end of the current sampling unit 20 is connected to the current regulating unit 30, and the second end of the current regulating unit 30 is electrically connected to the negative terminal 12. That is, the voltage regulating unit 60, the current sampling unit 20 and the current regulating unit are arranged in series between the positive terminal 11 and the negative terminal 12 to form a closed loop.

[0082] In combination with the above embodiments, in the process of performing performance testing on power supply devices such as power supplies, batteries, and charging chips, the voltage sampling unit 50 collects the voltage between the positive terminal 11 and the negative segment in real time and outputs it to the voltage control unit 42, the current sampling unit 20 collects the output current of the device under test and outputs it to the current control unit 41, the voltage control unit 42 compares the voltage value of the voltage sampling signal with the preset voltage threshold range, and when the voltage value of the voltage sampling signal is not within the preset voltage threshold range, controls the voltage adjustment unit 60 to adjust the voltage between the positive terminal 11 and the negative terminal 12, so that the test device operates in a constant voltage mode and limits the voltage of the device under test to within the preset voltage threshold range. Similarly, the current control unit 41 compares the current value of the current sampling signal with the preset current threshold range, and when the current value of the current sampling signal is not within the preset current threshold range, controls the current adjustment unit 30 to adjust the output current of the device under test, so that the test device (such as an electronic load) can quickly switch to a constant current mode in a constant voltage mode, and limit the output current of the device under test to within the preset current threshold range.

[0083] refer to Figure 4 , Figure 4It is a schematic diagram of a control circuit module in the prior art, wherein the transistor unit 1 is used as both a voltage regulating unit 60 and a current regulating unit 30, and the switch K is used as a switching switch, having a common end and a first regulating end and a second regulating end, the common end is connected to the transistor unit 1, the first regulating end is used to be connected to the control end of the voltage control unit 42, and the second regulating end is used to be electrically connected to the control end of the current control unit 41. When the electronic load works in a constant voltage mode, the first regulating end of the switch K is electrically connected to the control end of the voltage control unit 42, and the second regulating end of the switch K is suspended; when the electronic load works in a constant current mode, the second regulating end of the switch K is electrically connected to the control end of the current control unit 41, and the first regulating end of the switch K is suspended. When the voltage control unit 42 determines that the voltage is greater than the constant voltage set in the constant voltage mode according to the voltage sampling signal output by the voltage sampling unit 50, the control transistor unit 1 adjusts the voltage between the load terminal + and the load terminal - to limit the output voltage of the device under test to the constant voltage; when the current control unit 41 determines that the current is greater than the constant current set in the constant current mode according to the current sampling signal output by the current sampling unit 20, the control transistor unit 1 adjusts the current between the load terminal + and the load terminal - to limit the output current of the device under test to the constant current. However, when switching from the constant voltage mode to the constant current mode or vice versa, a certain switching time (including the state of the switch K) and a detection time are required to detect the current working state and adjust the control signal of the transistor unit 1 according to the new mode requirements. Therefore, this switching process involves changes in the control signal, the circuit response time, etc., which may cause short-term discontinuity, and the transistor unit 1 itself will also have a certain response time, that is, the delay between receiving the control signal and actually adjusting the output. This transition period may cause the device under test to work unstably or even damage sensitive components. For example, a short fluctuation in the output current may cause the device under test to overheat, damage, or affect its normal operation. During the mode switching process, abnormal data points may be recorded, resulting in inaccurate test results.

[0084] It should be noted that the current regulating unit 30 and the current sampling unit 20 can be connected in series at any position between the voltage regulating unit 60 and the negative terminal 12, as long as the current regulating unit 30, the current sampling unit 20 and the voltage regulating unit 60 are connected in series between the positive terminal 11 and the negative terminal 12 and are in the same closed loop. In this way, the flexibility of the control circuit of the present invention is improved and the design complexity is reduced.

[0085] In this embodiment, the voltage regulating unit 60 is connected in series with the current regulating unit 30, the current regulating unit 30 is connected in series with the current sampling unit 20, and the current sampling unit 20 is connected to the negative terminal 12. Through the voltage regulating unit 60 and the current regulating unit 30 connected in series, the voltage and current can be precisely controlled at the same time, ensuring that the output voltage and the output current can be kept within the corresponding preset threshold range even during the mode switching process. Since the voltage regulating unit 60 and the current regulating unit 30 are independently controlled, there is no need to switch the mode through the switch K, thereby reducing the delay and discontinuity during the mode switching process, and reducing the voltage and current fluctuations caused by the mode switching. In addition, the current regulating unit 30 directly limits the maximum current flowing through the device under test, preventing the instantaneous large current from damaging the device under test (such as a battery, a charging chip) or the test device (electronic load). In this way, the safety and reliability of the test process are improved.

[0086] In another embodiment, the current regulating unit 30 includes:

[0087] A first adjustable resistance unit, wherein an output end of the first adjustable resistance unit is electrically connected to the test end 10, and a controlled end of the first adjustable resistance unit is electrically connected to the adjustment control unit;

[0088] The regulation control unit is used to control the first adjustable resistance unit to adjust the resistance value of the first adjustable resistance unit when the current value of the current sampling signal is not within a preset current threshold range when the test device is in a constant voltage mode, so that the test device operates in a constant current mode and limits the output current flowing through the device under test to within a preset current threshold range.

[0089] refer to Figures 5 to 7 , the first adjustable resistance unit includes:

[0090] a first transistor circuit, wherein the first transistor circuit is electrically connected to the test terminal 10, and a controlled terminal of the first transistor circuit is electrically connected to the regulation control unit;

[0091] The regulating control unit is specifically used to regulate the conduction degree of the first transistor circuit so as to limit the output current flowing through the device under test to within a preset current threshold range.

[0092] In this embodiment, the first transistor circuit can be implemented by at least one MOSFET (metal oxide semiconductor field effect transistor), BJT (bipolar transistor), etc., wherein the number of MOSFETs or BJTs is determined by power, and the greater the power, the greater the number, and multiple transistors in the first transistor circuit are arranged in parallel. That is, the number of transistors can be expanded in parallel according to power requirements to adapt to different power requirements.

[0093] In combination with the above embodiments, the test terminal 10 for accessing the device under test includes a positive terminal 11 and a negative terminal 12, the voltage regulating unit 60 is arranged in series between the positive terminal 11 and the negative terminal 12, and the current regulating unit 30 includes a first adjustable resistance unit, and is arranged in series between the positive terminal 11 and the negative terminal 12. The voltage sampling unit 50 and the current sampling unit 20 are electrically connected to the test terminal 10 respectively, and the current sampling unit 20 is connected in series with the current regulating unit 30. The voltage sampling unit 50 collects the output voltage of the device under test and outputs the corresponding voltage sampling signal to the voltage control unit 42. The current sampling unit 20 collects the output current of the device under test and outputs the corresponding current sampling signal to the current control unit 41. The preset voltage threshold range is set in advance to ensure that the output voltage of the device under test is within the preset voltage threshold range during the test process. At the same time, the preset current threshold range is set to ensure that the output current of the device under test is within the preset current threshold range during the test process. If the voltage value obtained by sampling is higher than the upper limit value of the preset voltage threshold range or reaches the upper limit value, which is specifically set by the R&D personnel according to actual needs, the voltage control unit 42 will control the voltage regulating unit 60 to reduce the output voltage of the device under test. Similarly, if the current value is higher than the upper limit of the preset current threshold range or reaches the upper limit, the current control unit 41 will control the first adjustable resistance unit to adjust its own resistance value, such as increasing the resistance value to reduce the output current. In practical applications, if the current value is lower than the lower limit of the preset current threshold range or reaches the lower limit, the current control unit 41 will control the first adjustable resistance unit to adjust its own resistance value, such as reducing the resistance value to increase the output current. The lower limit is less than the upper limit.

[0094] In this embodiment, when the current value corresponding to the current sampling signal output by the current sampling unit 20 is higher than the upper limit value of the preset current threshold range or reaches the upper limit value, the current control unit 41 controls the first transistor circuit to adjust its own conduction degree to limit the current flowing through the device under test to within the preset current threshold range.

[0095] Specifically, MOSFET is used as the first transistor circuit for specific description. When the current control unit 41 determines that the current detected by the current sampling unit 20 is higher than or equal to the upper limit of the preset current threshold range, the current control unit 41 will reduce the gate voltage VGS of the MOSFET to reduce the conduction degree of the MOSFET, thereby increasing its equivalent resistance RDS. As RDS increases, the current flowing through the device under test will decrease to ensure that it is within the preset current threshold range. BJT is used as the first transistor circuit for specific description. When the current control unit 41 determines that the current detected by the current sampling unit 20 is higher than or equal to the upper limit of the preset current threshold range, the current control unit 41 will reduce the base current IB to reduce the conduction degree of the BJT, thereby increasing its equivalent resistance. As the equivalent resistance increases, the current IC flowing through the device under test will decrease to ensure that it is within the preset current threshold range.

[0096] MOSFET and BJT have fast response speeds and can adjust current quickly. The current regulating unit 30 can achieve fine control of the output current by accurately controlling the gate voltage or the base current. In addition, the transistor circuit can be integrated on a single chip, which simplifies the circuit design, reduces the number of external components, and improves the integration of the control circuit. The transistor itself also has an over-temperature protection function. When the temperature is too high, it can automatically reduce the degree of conduction to prevent damage to itself and external devices. In this way, the current flowing through the device under test can be effectively controlled to ensure that it is within the preset current threshold range, thereby improving the safety and accuracy of the test.

[0097] In one embodiment, the voltage regulating unit 60 includes:

[0098] a second adjustable resistance unit, wherein the second adjustable resistance unit is electrically connected to the test end 10, and a controlled end of the second adjustable resistance unit is electrically connected to the adjustment control unit;

[0099] The regulating control unit is used to control the second adjustable resistance unit to adjust the resistance value of the second adjustable resistance unit when the current value of the current sampling signal is within a preset current threshold range when the test device is in a constant voltage mode, so that the test device works in a constant voltage mode and the output voltage of the device under test is limited within a preset voltage threshold range;

[0100] And, it is used to control the second adjustable resistance unit to adjust the resistance value of the second adjustable resistance unit when the voltage value of the voltage sampling signal is not within a preset voltage threshold range when the test device is in a constant voltage mode, so that the test device operates in a constant voltage mode and limits the output voltage of the device under test to within a preset voltage threshold range.

[0101] refer to Figures 5 to 7, the second adjustable resistance unit includes:

[0102] a second transistor circuit, wherein the second transistor circuit is electrically connected to the test terminal 10, and a controlled terminal of the second transistor circuit is electrically connected to the regulation control unit;

[0103] The regulating control unit is specifically used to regulate the conduction degree of the second transistor circuit so as to limit the output voltage of the device under test within a preset voltage threshold range.

[0104] In this embodiment, the second transistor circuit can be implemented by at least one MOSFET (metal oxide semiconductor field effect transistor), BJT (bipolar transistor), etc., wherein the number of MOSFETs or BJTs is determined by power, and the greater the power, the greater the number, and multiple transistors in the second transistor circuit are arranged in parallel. That is, the number of transistors can be expanded in parallel according to power requirements to adapt to different power requirements.

[0105] In combination with the above-mentioned embodiments, the test terminal 10 for accessing the device under test includes a positive terminal 11 and a negative terminal 12, and the voltage regulating unit 60 includes a second adjustable resistance unit, which is arranged in series between the positive terminal 11 and the negative terminal 12. The voltage sampling unit 50 collects the output voltage of the device under test and outputs the corresponding voltage sampling signal to the voltage control unit 42. The preset voltage threshold range is set in advance to ensure that the output voltage of the device under test is within the preset voltage threshold range during the test. For example, when the test device is in constant voltage mode, if the sampled voltage value is higher than or equal to the upper limit value of the preset voltage threshold range, the voltage control unit 42 will control the second adjustable resistance unit to reduce the output voltage of the device under test. Similarly, if the sampled voltage value is lower than the lower limit value of the preset voltage threshold range, the voltage control unit 42 will control the second adjustable resistance unit to increase the output voltage of the device under test, so that the test device continues to work in the constant voltage mode, and the output voltage of the device under test is limited to the preset voltage threshold range. Among them, the lower limit value is less than the upper limit value. The control circuit of the present invention also enables the electronic load (test equipment) to have a constant current function in the constant voltage mode, that is, when the test equipment is in the constant voltage mode, when the current value of the current sampling signal is not within the preset current threshold range, the control device of the test system needs to switch the electronic load to the constant current mode to ensure that the output current of the device under test is within the preset current threshold range. When the current value of the current sampling signal is within the preset current threshold range, the electronic load still works in the constant voltage mode, and the voltage control unit 42 controls the resistance value of the second adjustable resistor according to the voltage sampling result to limit the output voltage of the device under test to within the preset voltage threshold range.

[0106] In this embodiment, when the voltage value corresponding to the voltage sampling signal output by the voltage sampling unit 50 is higher than the upper limit value of the preset voltage threshold range or reaches the upper limit value, the voltage control unit 42 controls the second transistor circuit to adjust its own conductivity and limit the voltage flowing through the device under test to within the preset current threshold range.

[0107] refer to Figure 5 The present invention proposes a control circuit of an electronic load with a constant current control function in a constant voltage mode. The control circuit is connected between a load terminal + (positive terminal 11) and a load terminal - (negative terminal 12), and includes a voltage sampling unit 50, a voltage control unit 42, a transistor unit 1 (a second transistor unit), a transistor unit 2 (a first transistor unit), a current sampling unit 20, and a current control unit 41; the transistor unit 2 is controlled by the current control unit 41 to change the current of the load terminal + and the load terminal -; the current control unit 41 generates a current for controlling the transistor unit 2 according to a comparison between a current value corresponding to a current sampling signal of the current sampling unit 20 and a preset current threshold range; the transistor unit 1 is controlled by the voltage control unit 42 to change the voltage of the load terminal + and the load terminal -; the voltage control unit 42 compares a voltage value corresponding to a voltage sampling signal of the voltage sampling unit 50 with a preset voltage threshold range, and generates a voltage between the load terminal + and - for controlling the transistor unit 1. Among them, the transistor unit 1 is connected in series with the transistor unit 2, the transistor unit 2 is connected in series with the current sampling unit 20, and the current sampling unit 20 is connected to the load terminal -. The transistor unit 2 and the current sampling unit 20 can be connected in series at any position between the transistor unit 1 and the load terminal + and the load terminal -, including but not limited to Figures 5 to 7 Position shown.

[0108] Specifically, MOSFET is used as the second transistor circuit for specific description. When the voltage control unit 42 determines that the voltage detected by the voltage sampling unit 50 is higher than or equal to the upper limit of the preset voltage threshold range, the voltage control unit 42 will reduce the gate voltage VGS of the MOSFET, so that the conduction degree of the MOSFET is reduced, thereby increasing its equivalent resistance RDS. As RDS increases, the current flowing through the device under test will decrease, thereby causing the voltage between the positive terminal 11 and the negative terminal 12 to drop until it returns to the preset voltage threshold range. If the voltage value is lower than the lower limit of the preset voltage threshold range, the voltage control unit 42 will increase the gate voltage VGS of the MOSFET, so that the conduction degree of the MOSFET is increased, thereby reducing its equivalent resistance RDS. As RDS decreases, the current flowing through the MOSFET increases, causing the voltage between the positive terminal 11 and the negative terminal 12 to rise until it returns to the preset voltage range. Taking BJT as the second transistor circuit for specific description, when the voltage control unit 42 determines that the voltage detected by the voltage sampling unit 50 is higher than or equal to the upper limit of the preset voltage threshold range, the voltage control unit 42 will reduce the base current IB to reduce the conduction degree of the BJT, thereby increasing its equivalent resistance. As the equivalent resistance increases, the current IC flowing through the device under test will decrease, causing the voltage between the positive terminal 11 and the negative terminal 12 to drop until it returns to the preset voltage threshold range.

[0109] It should be noted that, since the transistor unit 1 and the transistor unit 2 are connected in series between the load terminal + and the load terminal -, when the electronic load is in the constant voltage mode, the transistor unit 1 and the transistor unit 2 are both in working state, that is, the voltage control unit 42 controls the conduction degree of the transistor unit 1 according to the voltage sampling signal, ensuring that the output voltage of the device under test is maintained within the preset voltage threshold range, so that the test device (electronic load) maintains a constant voltage, and at the same time, the current control unit 41 controls the conduction degree of the transistor unit 2 according to the current detection signal, so that when the output current of the device under test is not within the preset current threshold range, it is adjusted to the preset current threshold range, so that the electronic load works in the constant current mode. Among them, when the electronic load is in the constant voltage mode, when the output current is less than the preset current threshold range, the current control unit 41 can control the transistor unit 2 to be fully turned on, and its equivalent resistance is very small, which can be regarded as a wire, realizing the direct electrical connection between the transistor unit 1 and the load terminal -. When the electronic load is in the constant current mode, the voltage control unit 42 can control the transistor unit 1 to be fully turned on, and its equivalent resistance is very small, which can be regarded as a wire, realizing the electrical connection between the load terminal + and the transistor unit 2. In constant voltage mode, the low impedance path of transistor unit 2 ensures the stability and accuracy of the output voltage. In constant current mode, the low impedance path of transistor unit 1 ensures the stability and accuracy of the output current. At the same time, the low resistance path reduces power loss and improves test efficiency. Compared with the prior art, the instability caused by the transition period of mode switching can be improved by only adding one transistor unit and setting the two transistor units in series. At the same time, in different working modes, it is only necessary to control the conduction degree of one transistor unit and control the other transistor unit to remain in a fully conductive state, which simplifies the control logic and circuit design. In this way, the electronic load can switch smoothly between constant voltage mode and constant current mode, which is suitable for a variety of test scenarios and requirements. The design of treating the transistor unit as a wire in a specific mode not only improves the test efficiency, but also simplifies the control logic and enhances the reliability and flexibility of the test.

[0110] Through the above settings, when the current of the device under test is greater than or equal to the constant current of the set electronic load, the electronic load is controlled to work in constant current mode, and when the current of the device under test is less than the constant current of the electronic load, the electronic load is controlled to work in constant voltage mode to complete the performance test of the device under test, such as constant current test. In this way, while meeting the user's test requirements for the device under test, when the product under test is connected to the load end, the current will not exceed the set constant current of the electronic load, which can effectively improve the risk of damage to the device under test or the test equipment, and improve the safety and reliability of the test work.

[0111] The present invention also proposes a protection control method, which uses the control circuit described above and includes:

[0112] Step S100, obtaining the working mode of the test device and the output current of the device under test;

[0113] Step S200: When the test device is in a constant voltage mode, when the current value of the output current is not within a preset current threshold range, control the test device to operate in a constant current mode to limit the output current of the device under test to within a preset current threshold range.

[0114] In this embodiment, the protection control method can be applied to a test system. For example, a memory for storing the protection control method of the present invention and a processor for executing the protection control method of the present invention are integrated in the control device of the test system. The control device can be implemented by a main controller, such as an MCU, a DSP (Digital Signal Process), an FPGA (Field Programmable Gate Array), a PLC, a SOC (System On Chip), etc. The control device of the test system can be separately set in a test device or a device under test, or it can be a controller of an external terminal connected to the device under test or the test device.

[0115] When it is necessary to use an electronic load to perform performance testing on a device under test such as a battery, power supply, or charging chip, first connect the device under test to the test terminal 10, and set a preset voltage threshold range in advance as the voltage value of the electronic load in constant voltage mode according to actual needs, and set a preset current threshold range as the current value of the electronic load in constant current mode. When everything is ready, start the device under test, provide power to the electronic load, and then the control device obtains the working mode of the test device, including a constant voltage module and a constant current mode. When the test device is in constant voltage mode, the current value corresponding to the current sampling signal output by the current sampling unit 20 in the control circuit is not within the preset current threshold range, for example, when the sampled current value reaches the upper limit of the preset current threshold range, the control device controls the electronic load to be in constant current mode to limit the output current of the device under test to within the preset current threshold range, so as to avoid triggering the current protection function during the test, terminating the test, or damaging the device under test and the electronic load due to excessive instantaneous current. It can be understood that when the test device is in the constant voltage mode, when the current value corresponding to the current sampling signal is within the preset current threshold range, the voltage control unit 42 determines whether the corresponding current value is greater than or equal to the preset voltage threshold range based on the voltage sampling signal output by the voltage sampling unit 50, and when the sampled voltage value is greater than or equal to the upper limit of the preset voltage threshold range, the voltage regulating unit 60 is controlled to reduce the output voltage of the device under test, and when the sampled voltage value is less than the lower limit of the preset voltage threshold range, the voltage regulating unit 60 is controlled to increase the output voltage of the device under test, so that the voltage of the positive terminal 11 and the negative segment is within the preset voltage threshold range. In addition, when the test device is in the constant current mode, when the current value corresponding to the current sampling signal output by the current sampling unit 20 in the control circuit is not within the preset current threshold range, for example, when the sampled current value reaches the upper limit of the preset current threshold range, the current control unit 41 will control the current regulating unit 30 to adjust the current to limit the output current of the device under test to within the preset current threshold range.

[0116] In actual applications, when the current of the device under test is greater than or equal to the constant current of the set electronic load, the control device will control the electronic load to work in constant current mode. When the product under test is connected to the load end, the current will not exceed the set constant current of the electronic load, which can effectively improve the risk of damage to the device under test or the test equipment. When the current of the device under test is less than the constant current of the electronic load, the control device controls the electronic load to work in constant voltage mode to complete the performance test of the device under test, such as constant current test. In this way, while meeting the user's testing requirements for the device under test, the safety and reliability of the test work are improved.

[0117] The present invention also proposes a testing device, which includes the control circuit or control device described above, and the control device includes a memory, a processor, and a computer program stored in the memory and executable on the processor, and the computer program is configured to implement the steps of the protection control method described above.

[0118] It is worth noting that since the test equipment of the present invention is based on the above-mentioned control circuit or protection control method, the embodiments of the test equipment of the present invention include all technical solutions of all embodiments of the above-mentioned control circuit or protection control method, and the technical effects achieved are also exactly the same, which will not be repeated here.

[0119] The present invention further proposes a test system, which includes the above-mentioned control circuit, or test equipment, and a device under test; the device under test is electrically connected to the test equipment.

[0120] In this embodiment, the device under test includes a power supply device such as a battery, a power supply, a charging chip, etc. that can provide power to the load. The test equipment includes an electronic device, which is a device used to test power supply devices such as power supplies, batteries, chargers, etc. It evaluates the performance of these devices under test by simulating actual load conditions. The electronic load can absorb and consume the electrical energy provided by the device under test, and can accurately control and measure parameters such as current, voltage, and power.

[0121] It is worth noting that since the test system of the present invention includes the above-mentioned control circuit or test equipment, the embodiments of the test system of the present invention include all technical solutions of all embodiments of the above-mentioned control circuit or test equipment, and the technical effects achieved are also exactly the same, which will not be repeated here.

[0122] The above descriptions are only optional embodiments of the present invention, and are not intended to limit the patent scope of the present invention. All equivalent structural changes made using the contents of the present invention's specification and drawings, or direct / indirect applications in other related technical fields, under the inventive concept of the present invention are included in the patent protection scope of the present invention.

Claims

1. A control circuit, characterized in that: The control circuit comprises: Test terminal, used to connect to the power supply terminal of the device under test; A current sampling unit, electrically connected to the test terminal, for collecting the output current of the device under test and outputting a corresponding current sampling signal; A current regulating unit, wherein an output end of the current regulating unit is connected to the test end; A regulating control unit connected to the controlled end of the current regulating unit; The regulation control unit is used to control the current regulation unit to regulate the output current of the device under test when the test device is in a constant voltage mode and the current value of the current sampling signal is not within a preset current threshold range, so that the test device operates in a constant current mode and the output current flowing through the device under test is limited to within a preset current threshold range.

2. The control circuit according to claim 1, characterized in that: The control circuit further comprises: A voltage sampling unit, electrically connected to the test terminal, for collecting the output voltage of the device under test and outputting a corresponding voltage sampling signal to the regulation control unit; A voltage regulating unit, wherein a controlled end of the voltage regulating unit is electrically connected to the regulating control unit; The regulation control unit is used to control the voltage regulation unit to adjust the output voltage of the device under test when the voltage value of the voltage sampling signal is not within the preset voltage threshold range, so that the test device operates in a constant voltage mode and limits the output voltage of the device under test to within the preset voltage threshold range.

3. The control circuit according to claim 1, characterized in that: The test end includes a positive terminal and a negative terminal, and the current regulating unit and the voltage regulating unit are arranged in series between the positive terminal and the negative terminal.

4. The control circuit according to claim 2, characterized in that: The current regulating unit comprises: a first adjustable resistance unit, wherein an output end of the first adjustable resistance unit is electrically connected to the test end, and a controlled end of the first adjustable resistance unit is electrically connected to the adjustment control unit; The regulation control unit is used to control the first adjustable resistance unit to adjust the resistance value of the first adjustable resistance unit when the current value of the current sampling signal is not within a preset current threshold range when the test device is in a constant voltage mode, so that the test device operates in a constant current mode and limits the output current flowing through the device under test to within a preset current threshold range.

5. The control circuit according to claim 4, characterized in that: The first adjustable resistance unit comprises: a first transistor circuit, wherein the first transistor circuit is electrically connected to the test end, and a controlled end of the first transistor circuit is electrically connected to the regulation control unit; The regulating control unit is specifically used to regulate the conduction degree of the first transistor circuit so as to limit the output current flowing through the device under test to within a preset current threshold range.

6. The control circuit according to claim 2, characterized in that: The voltage regulating unit comprises: a second adjustable resistance unit, wherein the second adjustable resistance unit is electrically connected to the test end, and a controlled end of the second adjustable resistance unit is electrically connected to the adjustment control unit; The regulating control unit is used to control the second adjustable resistance unit to adjust the resistance value of the second adjustable resistance unit when the current value of the current sampling signal is within a preset current threshold range when the test device is in a constant voltage mode, so that the test device works in a constant voltage mode and the output voltage of the device under test is limited within a preset voltage threshold range; And, it is used to control the second adjustable resistance unit to adjust the resistance value of the second adjustable resistance unit when the voltage value of the voltage sampling signal is not within a preset voltage threshold range when the test device is in a constant voltage mode, so that the test device operates in a constant voltage mode and limits the output voltage of the device under test to within a preset voltage threshold range.

7. The control circuit according to claim 6, characterized in that: The second adjustable resistance unit comprises: a second transistor circuit, wherein the second transistor circuit is electrically connected to the test end, and a controlled end of the second transistor circuit is electrically connected to the regulation control unit; The regulating control unit is specifically used to regulate the conduction degree of the second transistor circuit so as to limit the output voltage of the device under test within a preset voltage threshold range.

8. The control circuit according to claim 2, characterized in that: The regulating control unit comprises: A voltage control unit, wherein an input end of the voltage control unit is electrically connected to an output end of the voltage sampling unit, and a control end of the voltage control unit is electrically connected to the voltage regulating unit; The voltage control unit is used to control the voltage adjustment unit to adjust the output voltage of the device under test when the voltage value of the voltage sampling signal is not within the preset voltage threshold range, so that the test device works in a constant voltage mode and limits the voltage of the device under test to within the preset voltage threshold range; A current control unit, wherein an input end of the current control unit is electrically connected to an output end of the current sampling unit, and a control end of the current control unit is electrically connected to the current regulating unit; The current control unit is used to control the current regulation unit to adjust the output current of the device under test when the current value of the current sampling signal is not within a preset current threshold range, so that the test device operates in a constant current mode and limits the output current flowing through the device under test to within a preset current threshold range.

9. A protection control method, characterized in that: The protection control method uses the control circuit according to any one of claims 1 to 8, and the protection control method includes: Obtain the working mode of the test equipment and the output current of the device under test; When the test device is in constant voltage mode, when the current value of the output current is not within a preset current threshold range, the test device is controlled to operate in constant current mode to limit the output current of the device under test within a preset current threshold range.

10. A testing device, characterized in that: The test device comprises a control circuit as claimed in any one of claims 1 to 8, or, A control device, comprising: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the computer program is configured to implement the steps of the protection control method according to claim 9.

11. A testing system, characterized in that: The test system comprises the control circuit according to any one of claims 1 to 8, or the test device according to claim 10, and a device under test; the device under test is electrically connected to the test device.

Images