Switching tube test circuit, circuit board, test fixture and test system

Abstract

The invention relates to the technical field of testing, and discloses a switch tube testing circuit, a circuit board, a testing jig and a testing system. The switch tube test circuit comprises a power supply circuit, a test main loop, a current sampling circuit and a control circuit, the power supply circuit can provide voltage required by switch tube test, the test main loop comprises an auxiliary switch tube and can be connected to a tested switch tube, the current sampling circuit can sample current flowing through the tested switch tube, and the control circuit can test the current flowing through the tested switch tube according to a specified test mode. The method comprises the following steps: controlling a passive switch tube to be in a conduction state, and controlling the on-off of an active switch tube according to the current flowing through a tested switch tube in a specified test mode so as to test the tested switch tube, and when the active switch tube is one of the tested switch tube and an auxiliary switch tube, the passive switch tube is the other one. According to the embodiment of the invention, the test can be carried out when the tested switch tube is used as an active switch tube or a passive switch tube, the test scene can be expanded, and the tested switch tube can be tested more comprehensively.

Description

Technical Field

[0001] The present invention relates to the field of testing technology, and in particular to a switch tube testing circuit, a circuit board, a testing fixture, and a testing system. Background Art

[0002] Currently, dual-pulse testing is commonly used to test switching transistors. This method primarily tests the switch under test by adjusting the drive pulse width, causing a large pulse current to flow through the switch. In this test method, the switch under test can only be used as a switch that actively switches on and off to withstand current. The test scenarios are relatively limited and cannot cover the switching performance of the switch under test in various actual operating conditions, making it impossible to fully evaluate the switching performance of the switch under test. Summary of the Invention

[0003] An object of an embodiment of the present invention is to provide a switch tube test circuit, a circuit board, a test fixture, and a test system that can solve the defects existing in the prior art.

[0004] In a first aspect, an embodiment of the present invention provides a switch tube test circuit, comprising:

[0005] Power supply circuit, used to provide the voltage required for switching tube testing;

[0006] A test main circuit, comprising an auxiliary switch tube, wherein the auxiliary switch tube is electrically connected to the power supply circuit, and the test main circuit is used to access the switch tube under test;

[0007] a current sampling circuit, configured to be electrically connected to the switch tube under test and capable of sampling the current flowing through the switch tube under test;

[0008] The control circuit is used to be electrically connected to the power supply circuit, the auxiliary switch tube, the switch tube under test and the current sampling circuit respectively. It can control the passive switch tube to be in the on state according to a specified test mode, and in the specified test mode, control the on and off of the active switch tube according to the current flowing through the switch tube under test to test the switch tube under test. When the active switch tube is the switch tube under test, the passive switch tube is the auxiliary switch tube; when the active switch tube is the auxiliary switch tube, the passive switch tube is the switch tube under test.

[0009] In a second aspect, an embodiment of the present invention provides a circuit board comprising the switching tube test circuit as described above.

[0010] In a third aspect, an embodiment of the present invention provides a test fixture comprising the circuit board described above.

[0011] In a fourth aspect, an embodiment of the present invention provides a testing system, including:

[0012] A test fixture as described above; and

[0013] an auxiliary power supply, electrically connected to the test fixture, for supplying power to the test fixture; and

[0014] An electronic device is communicatively connected to the test fixture.

[0015] In the switch tube test circuit provided in an embodiment of the present invention, the switch tube test circuit includes a power supply circuit, a test main circuit, a current sampling circuit and a control circuit. The power supply circuit can provide the voltage required for the switch tube test. The test main circuit includes an auxiliary switch tube, which is electrically connected to the power supply circuit. The test main circuit can be connected to the switch tube under test. The current sampling circuit can be electrically connected to the switch tube under test to sample the current flowing through the switch tube under test. The control circuit can be electrically connected to the power supply circuit, the auxiliary switch tube, the switch tube under test and the current sampling circuit respectively. According to the specified test mode, the passive switch tube is controlled to be in the on state, and in the specified test mode, the active switch tube is controlled to be on and off according to the current flowing through the switch tube under test to test the switch tube under test. When the active switch tube is the switch tube under test, the passive switch tube is the auxiliary switch tube. When the active switch tube is the auxiliary switch tube, the passive switch tube is the switch tube under test. Therefore, this embodiment can not only be tested in the scenario where the switch tube under test acts as an active switch tube that actively switches on and off to withstand current, but can also be tested in the scenario where the switch tube under test acts as a passive switch tube that passively withstands current. It can expand the test scenarios, which is conducive to simulating more working conditions to perform more comprehensive tests on the switch tube under test, thereby facilitating a more comprehensive evaluation of the switching performance of the switch tube under test. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] One or more embodiments are illustrated only as examples through the pictures in the corresponding drawings, and these exemplary descriptions do not constitute limitations on the embodiments. Elements with the same reference numerals in the drawings represent similar elements, and unless otherwise stated, the figures in the drawings do not constitute a scale limitation.

[0017] Figure 1 This is a schematic diagram of an application scenario of a test system provided by an embodiment of the present invention;

[0018] Figure 2 is a structural diagram of a test system provided by an embodiment of the present invention;

[0019] Figure 3 is a structural diagram of a test system provided by another embodiment of the present invention;

[0020] Figure 4 is a structural diagram of a test system provided by another embodiment of the present invention;

[0021] Figure 5 is a structural diagram of a test system provided by another embodiment of the present invention;

[0022] Figure 6 is a structural diagram of a test system provided by another embodiment of the present invention;

[0023] Figure 7 It is a structural diagram of a testing system provided by another embodiment of the present invention. DETAILED DESCRIPTION

[0024] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0025] It should be noted that, unless there is a conflict, the various features of the embodiments of the present invention may be combined with each other and are all within the scope of protection of the present invention. In addition, although the functional modules are divided in the device schematics and the logical order is shown in the flow charts, in some cases, the steps shown or described may be performed in a different order than the module division in the device or the order in the flow charts. Furthermore, the terms "first," "second," "third," etc. used in the present invention do not limit the data or execution order, but only distinguish between identical or similar items with substantially the same functions and effects.

[0026] The embodiment of the present invention provides an application scenario of a test system. Figure 1 , the application scenario includes a test system 1000 and a switch tube 2000 under test.

[0027] The test system 1000 is electrically connected to a switch transistor under test 2000 and is used to test the switch transistor under test 2000. The switch transistor under test 2000 is the switch transistor under test, wherein the switch transistor under test 2000 includes any suitable switch transistor, such as an IGBT (Insulated Gate Bipolar Transistor), a MOS (Metal-Oxide-Semiconductor), or the like. In some embodiments, the switch transistor under test 2000 is an IGBT.

[0028] See also Figure 2 The test system 1000 includes a test fixture 100 , an auxiliary power supply 200 and an electronic device 300 .

[0029] The test fixture 100 can be connected to the switch tube 2000 to test the switch tube 2000. By testing the switch tube 2000, various switching characteristics of the switch tube 2000 can be evaluated so that the switch tube 2000 can be used in a suitable circuit module.

[0030] The auxiliary power supply 200 is electrically connected to the test fixture 100 and can power the test fixture 100 to ensure that the test fixture 100 completes the process of testing the switch tube 2000 under test. The auxiliary power supply 200 can be an AC power supply or a DC power supply. When the auxiliary power supply 200 is an AC power supply, the auxiliary power supply 200 can provide an AC voltage to the test fixture 100. When the auxiliary power supply 200 is a DC power supply, the auxiliary power supply 200 can provide a DC voltage to the test fixture 100.

[0031] The process of testing the switch tube 2000 under test includes a startup phase and a test phase. During the startup phase, the auxiliary power supply 200 starts to supply power to the test fixture 100. When the voltage required by the test fixture 100 to test the switch tube 2000 under test is reached or the specified startup time is reached, the startup phase ends and the test phase can be entered immediately. During the test phase, the test fixture 100 can test the switch tube 2000 under test.

[0032] The electronic device 300 is communicatively connected to the test fixture 100. The electronic device 300 can provide a user operation interactive interface and display feedback data to the user. When the user interacts with the electronic device 300 through the user operation interactive interface, the electronic device 300 can directly issue control commands to the test fixture 100 so that the test fixture 100 performs the corresponding test operation according to the control commands. The test fixture 100 can also transmit data such as voltage, current, waveform, etc. to the electronic device 300 so that the electronic device 300 can automatically generate a test result report based on this data and provide it to the user.

[0033] In some embodiments, the electronic device 300 includes terminal devices such as workstations, desktop computers, laptops, industrial computers, tablet computers, smart phones, smart watches, etc.

[0034] In some embodiments, please refer to Figure 3 and Figure 4 The test fixture 100 includes a test main circuit 11 , a control circuit 12 , a power circuit 13 and a current sampling circuit 14 .

[0035] like Figure 4 As shown, the test main loop 11 includes an auxiliary switch tube 111, which is a switch tube for assisting in testing the switch tube 2000 under test. The auxiliary switch tube 111 can include any suitable switch tube such as IGBT, MOS tube, etc.

[0036] The test main circuit 11 can be connected to the switch tube under test 2000. In some embodiments, the auxiliary switch tube 111 is a high-power IGBT whose rated current is more than twice the rated current of the switch tube under test 2000. In addition, since the high-power IGBT is a heat-sensitive component, it generates a relatively large amount of heat during the test process. Therefore, in order to improve the reliability and stability of the test, it is necessary to dissipate heat from the high-power IGBT. In some embodiments, the test fixture 100 is provided with a heat sink. The high-power IGBT can be mounted to the heat sink using thermal grease. This allows the heat generated by the high-power IGBT to be more effectively transferred to the heat sink and then dissipated into the surrounding air through the heat sink, thereby dissipating heat from the high-power IGBT. The heat sink can be made of a metal material such as aluminum alloy, brass, or bronze.

[0037] like Figure 4 As shown, the test main circuit 11 further includes a current limiting circuit 112 and a freewheeling circuit 113 .

[0038] The current limiting circuit 112 is electrically connected to the auxiliary switch 111 and the switch under test 2000 , respectively, and is used to store energy to limit the current flowing through the auxiliary switch 111 or the switch under test 2000 .

[0039] The freewheeling circuit 113 is electrically connected to the current limiting circuit 112 , the auxiliary switch tube 111 and the switch tube under test 2000 , respectively, and is used to provide a freewheeling path when the current limiting circuit 112 releases energy.

[0040] On the one hand, this embodiment can limit the current flowing through the auxiliary switch tube 111 or the tested switch tube 2000 through the current limiting circuit 112 during the test phase, so that the current-carrying capacity meets the test requirements. On the other hand, the freewheeling circuit 113 provides a freewheeling path when the current limiting circuit 112 releases energy, ensuring that the test main circuit 11 will not cause risks due to excessive voltage.

[0041] In some embodiments, see Figure 7 , the current limiting circuit 112 includes an inductor L1.

[0042] One end of the inductor L1 is electrically connected to the auxiliary switch tube 111 and the freewheeling circuit 113 , respectively. The other end of the inductor L1 is electrically connected to the switch tube 2000 under test and the freewheeling circuit 113 , respectively.

[0043] In this embodiment, the inductance of the inductor L1 can be set according to the current rise rate requirements of the auxiliary switch tube 111 and the tested switch tube 2000.

[0044] The switch tube 2000 under test can be set on the freewheeling path or not. When the switch tube 2000 under test is set on the freewheeling path, if the switch tube 2000 under test is damaged during the test process, the current limiting circuit 112 has no freewheeling path to release energy, which may easily cause the voltage of the test main circuit 11 to be too high, thereby causing risks. When the switch tube 2000 under test is not set on the freewheeling path, even if the switch tube 2000 under test is damaged during the test process, it will not affect the freewheeling path, thereby reducing the risk of the test main circuit 11 caused by excessive voltage.

[0045] In some embodiments, the freewheeling circuit 113 includes a diode D1. Figure 7 When the switch tube 2000 under test is not set on the freewheeling path, the cathode of the diode D1 is electrically connected to the auxiliary switch tube 111 and the current limiting circuit 112 respectively, and the anode of the diode D1 is electrically connected to the switch tube 2000 under test and the current limiting circuit 112 respectively.

[0046] Please continue reading Figure 4 The control circuit 12 includes a controller 121 , a first driving circuit 122 and a second driving circuit 123 .

[0047] The controller 121 is in communication with the electronic device 300 and serves as the control core of the test fixture 100. The controller 121 can control the operating state of the test fixture 100 according to the control commands sent by the electronic device 300. For example, during the test phase, the electronic device 300 sends an instruction to the controller 121 to execute a specified test mode. The specified test mode is a preset test mode for a specific test scenario. The controller 121 can control the test fixture 100 to enter the operating state corresponding to the specified test mode according to the specified test mode corresponding to the instruction, thereby completing the test process under the test scenario corresponding to the specified test mode.

[0048] In some embodiments, the controller 121 can be any general-purpose processor, digital signal processor (DSP), application-specific integrated circuit (ASIC), field-programmable gate array (FPGA), single-chip microcomputer, ARM (Acorn RISC Machine) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination of these components. In addition, the controller 121 can also be any conventional processor, controller, microcontroller or state machine. The controller 121 can also be implemented as a combination of computing devices, such as a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors in combination with a DSP, and / or any other such configuration.

[0049] The first driving circuit 122 is electrically connected to the controller 121 and the auxiliary switch tube 111 respectively, and can control the on and off of the auxiliary switch tube 111 under the control of the controller 121 .

[0050] The second driving circuit 123 is electrically connected to the controller 121 and the switch tube 2000 under test, and can control the on and off of the switch tube 2000 under test under the control of the controller 121 .

[0051] like Figure 4 As shown, the power supply circuit 13 includes a first voltage detection circuit 131 , a storage circuit 132 , a second voltage detection circuit 133 , a charging circuit 134 and a discharging circuit 135 .

[0052] The first voltage detection circuit 131 is electrically connected to the auxiliary power supply 200 and the controller 121 , respectively, and is configured to detect the voltage of the auxiliary power supply 200 .

[0053] The energy storage circuit 132 is electrically connected to the test main circuit 11, and is used to generate the voltage required to test the tested switch tube 2000 and provide it to the test main circuit 11. In some embodiments, the energy storage circuit 132 is electrically connected to the auxiliary switch tube 111 through a DC bus.

[0054] The energy storage circuit 132 may include one or more capacitors, wherein the number of capacitors of the multiple capacitors may be set according to actual needs, for example, the number of capacitors of the multiple capacitors may be 4, 6, 8, etc. The energy storage circuit 132 may include at least one electrolytic capacitor. For example, when the energy storage circuit 131 includes one capacitor, the capacitor may be an electrolytic capacitor. When the energy storage circuit 131 includes multiple capacitors, the multiple capacitors may include some electrolytic capacitors, or all of the multiple capacitors may be electrolytic capacitors. For example, when the number of capacitors of the multiple capacitors is 4, the number of electrolytic capacitors in the multiple capacitors may be 1, 2, 3, or 4.

[0055] In some embodiments, please refer to Figure 7 The energy storage circuit 132 includes a first capacitor E1, a second capacitor E2, a third capacitor E3, and a fourth capacitor E4. The first capacitor E1, the second capacitor E2, the third capacitor E3, and the fourth capacitor E4 are all electrically connected to the DC bus. In some embodiments, the first capacitor E1, the second capacitor E2, the third capacitor E3, and the fourth capacitor E4 are all electrolytic capacitors.

[0056] The second voltage detection circuit 133 is electrically connected to the energy storage circuit 132 and the controller 121 , respectively, and is used to detect the voltage of the energy storage circuit 132 .

[0057] The charging circuit 134 is electrically connected to the controller 121, the energy storage circuit 132 and the auxiliary power supply 200 respectively. Under the control of the controller 121, the charging circuit 134 can control the auxiliary power supply 200 to charge the energy storage circuit 132, so that the energy storage circuit 132 generates the voltage required to test the switch tube 2000 under test and provides it to the test main circuit 11.

[0058] The charging circuit 134 can form a pre-charging path and a direct-charging path with the energy storage circuit 132 respectively. When entering the startup phase, first, the auxiliary power supply 200 is activated, and the controller 121 detects whether the voltage of the auxiliary power supply 200 reaches a first preset voltage value. If the voltage of the auxiliary power supply 200 reaches the first preset voltage value, it means that the voltage output by the auxiliary power supply 200 is normal at this time, so the controller 121 selects the pre-charging path, so that the auxiliary power supply 200 pre-charges the energy storage circuit 132 through the pre-charging path. At this time, the voltage of the energy storage circuit 132 begins to rise continuously. Then, the controller 121 detects whether the voltage of the energy storage circuit 132 reaches a second preset voltage value. If the voltage of the energy storage circuit 132 reaches the second preset voltage value, it means that the voltage of the energy storage circuit 132 reaches the voltage required for testing the switch tube 2000 under test. At this time, the controller 121 selects the direct-charging path, so that the auxiliary power supply 200 charges the energy storage circuit 132 through the direct-charging path to maintain the voltage of the energy storage circuit 132 at the voltage required for testing the switch tube 2000 under test.

[0059] When the test system 1000 is powered on and enters the startup phase, the controller 121 first controls the charging circuit 134 and the energy storage circuit 132 to form a pre-charging path, so that the auxiliary power supply 200 pre-charges the energy storage circuit 132 through the pre-charging path. When the voltage of the energy storage circuit 132 reaches the requirement, the charging circuit 134 and the energy storage circuit 132 are controlled to form a direct charging path, so that the auxiliary power supply 200 directly charges the energy storage circuit 132. When entering the startup phase, it can limit the auxiliary power supply 200 from charging the large capacitor on the DC bus at the moment of activation to generate excessive current and damage the device.

[0060] In some embodiments, see Figure 5 The charging circuit 134 includes a pre-charging circuit 1341 and a direct charging circuit 1342 .

[0061] The pre-charging circuit 1341 is electrically connected to the auxiliary power supply 200 , the energy storage circuit 132 and the controller 121 , respectively. The pre-charging circuit 1341 and the energy storage circuit 132 can form a pre-charging path.

[0062] Please continue reading Figure 7 The pre-charging circuit 1341 includes a first resistor R1 and a first switch 13411 .

[0063] One end of the first resistor R1 is electrically connected to the auxiliary power supply 200 , and the other end of the first resistor R1 is electrically connected to the first switch 13411 . The first switch 13411 is also electrically connected to the controller 121 and the energy storage circuit 132 .

[0064] The first resistor R1 is a pre-charging resistor, which is used to limit the charging current of the auxiliary power supply 200 to charge the energy storage circuit 132, so as to prevent the capacitor connected to the DC bus from being damaged due to excessive charging current. As mentioned above, when the voltage of the auxiliary power supply 200 does not reach the first preset voltage value, the first switching switch 13411 is in an open state. When it is detected that the voltage of the auxiliary power supply 200 reaches the first preset voltage value, the controller 121 can control the first switching switch 13411 to be in a closed state. At this time, the auxiliary power supply 200, the first resistor R1, the first switching switch 13411 and the energy storage circuit 132 form a pre-charging path, so that the auxiliary power supply 200 charges the energy storage circuit 132 through the first resistor R1, causing the voltage of the energy storage circuit 132 to continuously increase.

[0065] The first switching switch 13411 may include any suitable switching device, such as a contactor, a relay, etc.

[0066] The direct charging circuit 1342 is electrically connected to the auxiliary power supply 200 , the energy storage circuit 132 and the controller 121 , respectively. The direct charging circuit 1342 and the energy storage circuit 132 can form a direct charging path.

[0067] like Figure 7 As shown, the direct charging circuit 1342 includes a second switch 13421 .

[0068] The second switch 13421 is electrically connected to the auxiliary power supply 200, the energy storage circuit 132, and the controller 121. As previously described, during the voltage increase of the energy storage circuit 132, when it is detected that the voltage of the energy storage circuit 132 has reached a second preset voltage value, the controller 121 can control the second switch 13421 to be in a closed state. At this time, the auxiliary power supply 200, the second switch 13421, and the energy storage circuit 132 form a direct charging path, so that the auxiliary power supply 200 directly charges the energy storage circuit 132, so that the voltage of the energy storage circuit 132 is maintained at a certain value.

[0069] Please continue reading Figure 5 The charging circuit 134 can be applied to the test system 1000 in which the auxiliary power supply 200 is a DC power supply. Figure 6 The charging circuit 134 further includes a rectifier circuit 1343 . The charging circuit 134 can be applied to the test system 1000 when the auxiliary power supply 200 is an AC power supply.

[0070] The rectifier circuit 1343 is electrically connected to the auxiliary power supply 200, the pre-charging circuit 1341 and the direct charging circuit 1342 respectively. The difference between the test system 1000 in which the auxiliary power supply 200 is a DC power supply is that the test system 1000 in which the auxiliary power supply 200 is an AC power supply can rectify the AC power output by the auxiliary power supply 200 through the rectifier circuit 1343 and then output DC power.

[0071] In the test system 1000 in which the auxiliary power supply 200 is an AC power supply, the auxiliary power supply 200 can be a single-phase AC power supply or a three-phase AC power supply. Accordingly, the rectifier circuit 1343 can include a single-phase rectifier bridge circuit or a three-phase rectifier bridge circuit. When the auxiliary power supply 200 is a single-phase AC power supply, the rectifier circuit 1343 is a single-phase rectifier bridge circuit. When the auxiliary power supply 200 is a three-phase AC power supply, the rectifier circuit 1343 is a three-phase rectifier bridge circuit. Figure 7 Taking the auxiliary power supply 200 as a single-phase AC power supply as an example, the rectifier circuit 1343 includes a single-phase rectifier bridge circuit composed of a second diode D2, a third diode D3, a fourth diode D4 and a fifth diode D5.

[0072] The discharge circuit 135 is electrically connected to the energy storage circuit 132 and is used to release the energy on the DC bus when the test system 1000 is powered off, thereby reducing the voltage of the DC bus and improving safety.

[0073] The discharge circuit 135 may include one resistor or multiple resistors, see Figure 7 The discharge circuit 135 includes a second resistor R2, a third resistor R3, a fourth resistor R4 and a fifth resistor R5. One end of the second resistor R2 and one end of the third resistor R3 are electrically connected to the energy storage circuit 132, respectively. The other end of the second resistor R2, the other end of the third resistor R3, one end of the fourth resistor R4 and one end of the fifth resistor R5 are electrically connected. One end of the fourth resistor R4 and the other end of the fifth resistor R5 are electrically connected to the energy storage circuit 132 and the switch tube 2000 under test, respectively.

[0074] Please continue reading Figure 3 The current sampling circuit 14 is electrically connected to the controller 121 and the switch tube 2000 under test, respectively, and can sample the current flowing through the switch tube 2000 under test and transmit the current sampling signal to the controller 121, so that the controller 121 can determine the current flowing through the switch tube 2000 under test based on the current sampling signal.

[0075] In some embodiments, the current sampling circuit 14 is a Hall sensor. A Hall sensor is a magnetic field sensor based on the Hall effect, which is a type of magnetoelectric effect. A Hall sensor primarily consists of a Hall element and a magnetic field sensor. When current passes through the Hall element, a magnetic field is generated around it. The magnetic field sensor detects changes in this magnetic field and converts it into a voltage signal output. When this voltage signal is transmitted to the controller 121, the controller 121 converts the voltage signal into a corresponding current value, thereby enabling the controller 121 to indirectly detect the current flowing through the switch tube 2000 under test.

[0076] As mentioned above, during the test phase, when the controller 121 receives an instruction from the electronic device 300 to execute a specified test mode, in some embodiments, the controller 121 controls the passive switch tube to be in the on state according to the specified test mode, and in the specified test mode, controls the on and off of the active switch tube according to the current flowing through the switch tube under test 2000 to test the switch tube under test 2000. When the active switch tube is the switch tube under test 2000, the passive switch tube is the auxiliary switch tube 111; when the active switch tube is the auxiliary switch tube 111, the passive switch tube is the switch tube under test 2000.

[0077] In this embodiment, the active switch tube is a switch tube that is actively turned on and off to bear the current, and the passive switch tube is a switch tube that is in the on state to passively bear the current.

[0078] The controller 121 can output a first control signal to the first driver circuit 122 and a second control signal to the second driver circuit 123 according to a specified test mode. The first driver circuit 122 controls the on / off switching of the auxiliary switch 111 in response to the first control signal, and the second driver circuit 123 controls the on / off switching of the switch under test 2000 in response to the second control signal. The first control signal or the second control signal includes a first level type signal and a second level type signal. The first level type signal and the second level type signal are signals of different level types. For example, the first level type signal is a high level signal and the second level type signal is a low level signal, or the first level type signal is a low level signal and the second level type signal is a high level signal.

[0079] In some embodiments, the first control signal or the second control signal may be a pulse signal.

[0080] In a specified test mode, the switch tube 2000 under test can be used as an active switch tube to be actively turned on and off to bear the current, or can be used as a passive switch tube to be in the on state to passively bear the current.

[0081] For example, in a specified test mode, the controller 121 continuously outputs a first level type signal to the first drive circuit 122 according to the specified test mode, so that the first drive circuit 122 responds to the first level type signal to control the auxiliary switch tube 111 to be in the on state, and in the specified test mode, the controller 121 outputs a pulse signal of corresponding pulse width to the second drive circuit 123 according to the current flowing through the switch tube under test 2000, so that the second drive circuit 123 responds to the pulse signal to control the on and off of the switch tube under test 2000. At this time, since the switch tube under test 2000 is actively turned on and off to bear the current, the auxiliary switch tube 111 is in the on state to passively bear the current. Therefore, in the specified test mode, the switch tube under test 2000 is an active switch tube, and the auxiliary switch tube 111 is a passive switch tube.

[0082] For another example, in a specified test mode, the controller 121 continuously outputs a first level type signal to the second drive circuit 123 according to the specified test mode, so that the second drive circuit 123 responds to the first level type signal to control the tested switch tube 2000 to be in the on state, and in the specified test mode, the controller 121 outputs a pulse signal of corresponding pulse width to the first drive circuit 122 according to the current flowing through the tested switch tube 2000, so that the first drive circuit 122 responds to the pulse signal to control the on and off of the auxiliary switch tube 111. At this time, since the auxiliary switch tube 111 actively switches on and off to bear the current, the tested switch tube 2000 is in the on state to passively bear the current. Therefore, in the specified test mode, the auxiliary switch tube 111 is an active switch tube, and the tested switch tube 2000 is a passive switch tube.

[0083] Therefore, this embodiment can not only be tested in the scenario where the switch tube under test 2000 acts as an active switch tube that actively switches on and off to withstand current, but can also be tested in the scenario where the switch tube under test 2000 acts as a passive switch tube that passively withstands current. It can expand the test scenarios, which is conducive to simulating more working conditions to perform more comprehensive tests on the switch tube under test 2000, thereby facilitating a more comprehensive evaluation of the switching performance of the switch tube under test 2000.

[0084] In some embodiments, the designated test mode includes a pulse current test mode, which is a test mode for controlling a pulse current to flow through the switch tube under test 2000. In the pulse current test mode, the controller 121 controls the passive switch tube to be in the on state and applies a pulse signal of a first preset pulse width to the active switch tube. Based on the current flowing through the switch tube under test 2000, the pulse width of the pulse signal is increased based on the first preset pulse width to increase the current flowing through the switch tube under test 2000. When the controller 121 detects that the peak current flowing through the switch tube under test 2000 reaches the first preset current value, a pulse signal of a second preset pulse width is applied to the active switch tube. The pulse width of the first preset pulse width, the first preset current value, and the pulse width of the second preset pulse width can be set according to actual test requirements and are not specifically limited here.

[0085] In some embodiments, the pulse current test mode includes an active test mode and a passive test mode, wherein the active test mode is a test mode that controls the switch tube 2000 under test as an active switch tube to actively turn on and off to withstand the pulse current, and the passive test mode is a test mode that controls the switch tube 2000 under test as a passive switch tube to be in the on state to passively withstand the pulse current.

[0086] When the pulse current test mode is the active test mode, the passive switch tube is the auxiliary switch tube 111 , and the active switch tube is the switch tube under test 2000 .

[0087] In this embodiment, the controller 121 outputs a first level type signal to the first drive circuit 122 according to the active test mode. The first drive circuit 122 controls the auxiliary switch tube 111 to be in the on state in response to the first level type signal, and applies a pulse signal of a first preset pulse width to the switch tube under test 2000, so that current flows through the switch tube under test 2000 and the auxiliary switch tube 111. The pulse width of the first preset pulse width is relatively small, so that a relatively small current flows through the switch tube under test 2000. At this time, the controller 121 detects the current of the auxiliary switch tube 111 according to the current sampling circuit 14. The controller 121 detects the peak current value flowing through the switch tube 2000 under test, and increases the pulse width of the pulse signal based on the first preset pulse width according to the peak current value, so as to slowly increase the current flowing through the switch tube 2000 under test. When the controller 121 detects that the peak current value flowing through the switch tube 2000 under test reaches the first preset current value, a pulse signal with a second preset pulse width is applied to the switch tube 2000 under test, thereby testing the switch tube 2000 under test. Subsequently, the controller 121 can collect corresponding parameters to determine the switching performance of the switch tube 2000 under test when it is used as an active switch tube.

[0088] When the pulse current test mode is a passive test mode, the passive switch tube is the tested switch tube 2000 , and the active switch tube is the auxiliary switch tube 111 .

[0089] In this embodiment, the controller 121 outputs a first level type signal to the second drive circuit 123 according to the passive test mode. The second drive circuit 123 controls the switch tube 2000 under test to be in the on state in response to the first level type signal, and applies a pulse signal of a first preset pulse width to the auxiliary switch tube 111, so that current flows through the auxiliary switch tube 111 and the switch tube 2000 under test. The pulse width of the first preset pulse width is relatively small, so that a relatively small current flows through the auxiliary switch tube 111. At this time, the controller 121 detects the current sampling of the current sampling circuit 14 according to the current sampling signal of the current sampling circuit 14. Signal, detect the current peak value flowing through the tested switch tube 2000, and increase the pulse width of the pulse signal on the basis of the first preset pulse width according to the current peak value, so as to slowly increase the current flowing through the tested switch tube 2000. When the controller 121 detects that the current peak value flowing through the tested switch tube 2000 reaches the first preset current value, a pulse signal with a second preset pulse width is applied to the auxiliary switch tube 111, thereby testing the tested switch tube 2000. Subsequently, the controller 121 can collect corresponding parameters to determine the switching performance of the tested switch tube 2000 when it is used as a passive switch tube.

[0090] In some embodiments, the designated test mode includes a constant current test mode, which is a test mode in which a constant current is controlled to flow through the switch tube under test 2000. In the constant current test mode, the controller 121 controls the switch tube under test 2000 to be in the on state and applies a pulse signal with a third preset pulse width to the auxiliary switch tube 111. Based on the current flowing through the switch tube under test 2000, the pulse width of the pulse signal is increased based on the third preset pulse width to increase the current flowing through the switch tube under test 2000. When it is detected that the effective value of the current flowing through the switch tube under test 2000 reaches the second preset current value, a pulse signal with a fourth preset pulse width is applied to the auxiliary switch tube 111. The pulse width of the third preset pulse width, the second preset current value, and the pulse width of the fourth preset pulse width can be set according to actual test requirements and are not specifically limited here.

[0091] In this embodiment, the pulse signal of the third preset pulse width is a pulse signal with a fixed frequency, and the frequency can be set according to actual needs, for example, the frequency is set to 100 kHz. The pulse width of the first preset pulse width is relatively small, so that a smaller current flows through the switch tube under test 2000. At this time, the controller 121 detects the effective value of the current flowing through the switch tube under test 2000 based on the current sampling signal of the current sampling circuit 14, and increases the pulse width of the pulse signal on the basis of the third preset pulse width based on the effective value of the current to slowly increase the current flowing through the switch tube under test 2000. When the controller 121 detects that the effective value of the current flowing through the switch tube under test 2000 reaches the second preset current value, the controller 121 applies a pulse signal of a fourth preset pulse width to the switch tube under test 2000, thereby testing the switch tube under test 2000. Subsequently, the controller 121 can collect corresponding parameters to determine the switching performance of the switch tube under test 2000 in the constant current state when it is a passive switch tube.

[0092] Therefore, this embodiment can perform constant current testing in a scenario where the switch tube under test 2000 acts as a passive switch tube that passively withstands current, which can further expand the test scenario, facilitate a more comprehensive test of the switch tube under test 2000, and thus facilitate a more comprehensive evaluation of the switching performance of the switch tube under test 2000.

[0093] In some embodiments, please refer to Figure 6 The first driving circuit 122 includes a first voltage output unit 1121 , a first voltage feedback unit 1122 and a first driving unit 1123 .

[0094] The first voltage output unit 1121 is electrically connected to the controller 121 and is configured to output voltage under the control of the controller 121 .

[0095] The first voltage feedback unit 1122 is used to be electrically connected to the first voltage output unit 1121 and the controller 121 respectively, and is used to sample the voltage output by the first voltage output unit 1121 and feed the voltage back to the controller 121, so that the controller 121 adjusts the voltage output by the first voltage output unit 1121 according to the feedback voltage, so that the voltage output by the first voltage output unit 1121 is stabilized at a preset voltage.

[0096] In some embodiments, the first voltage output unit 1121 is a flyback power supply.

[0097] The first driving unit 1123 is electrically connected to the controller 121 and the auxiliary switch tube 111 respectively, and is configured to control the on / off switching of the auxiliary switch tube 111 in response to a first control signal output by the controller 121 .

[0098] In some embodiments, as Figure 3As shown, the second driving circuit 123 includes a second voltage output unit 1131 , a second voltage feedback unit 1132 and a second driving unit 1133 .

[0099] The second voltage output unit 1131 is electrically connected to the controller 121 , and is configured to output voltage under the control of the controller 121 .

[0100] The second voltage feedback unit 1132 is used to be electrically connected to the second voltage output unit 1131 and the controller 121 respectively, and is used to sample the voltage output by the second voltage output unit 1131 and feed the voltage back to the controller 121, so that the controller 121 adjusts the voltage output by the second voltage output unit 1131 according to the feedback voltage, so that the voltage output by the second voltage output unit 1131 is stabilized at a preset voltage.

[0101] The second driving unit 1133 is electrically connected to the controller 121 and the switch tube 2000 under test, and can control the on / off of the switch tube 2000 under test in response to the second control signal output by the controller 121 .

[0102] In some embodiments, the second voltage output unit 1131 is a flyback power supply.

[0103] In some embodiments, the controller 121 can also respond to a specified test mode and output a first control signal, a second control signal, a third control signal and a fourth control signal. The first driving unit 1123 can respond to the first control signal to control the on and off of the auxiliary switch tube 111. The second driving unit 1133 can respond to the second control signal to control the on and off of the switch tube under test 2000. The first voltage output unit 1121 is used to respond to the third control signal and output a driving voltage for applying to the auxiliary switch tube 111. The second voltage output unit 1131 is used to respond to the fourth control signal and output a driving voltage for applying to the switch tube under test 2000.

[0104] The third control signal or the fourth control signal includes a first level type signal and a second level type signal, and the first level type signal and the second level type signal are signals of different level types. For example, the first level type signal is a high level signal and the second level type signal is a low level signal, or the first level type signal is a low level signal and the second level type signal is a high level signal.

[0105] In some embodiments, the third control signal or the fourth control signal may be a pulse signal.

[0106] This embodiment can perform a more comprehensive test by changing the driving voltage of the auxiliary switch tube 111 or the switch tube under test 2000 in a specific test mode.

[0107] For example, the active test mode includes a 12V active test mode and a 15V active test mode. Taking the 15V active test mode as an example, the controller 121 continuously outputs a first level type signal (such as a high level signal) to the first driving unit 1123 according to the 15V active test mode, so that the first driving unit 1123 responds to the first level type signal to control the auxiliary switch tube 111 to be in the on state, and at the same time outputs a pulse signal to the first voltage output unit 1121. The first voltage output unit 1121 outputs a voltage in response to the pulse signal. The first voltage feedback circuit feeds back the voltage output by the first voltage output unit 1121 to the controller 121. The controller 121 adjusts the pulse signal output to the first voltage output unit 1121 according to the feedback voltage value, so that the voltage output by the first voltage output unit 1121 is stable at 15V. At this time, the auxiliary switch tube 111 is in the on state under the application of a driving voltage of 15V.

[0108] At the same time, the controller 121 applies a pulse signal of a first preset pulse width to the second driving unit 1133 to the switch tube 2000 under test, and outputs a pulse signal to the second voltage output unit 1131. The second voltage output unit 1131 outputs a voltage in response to the pulse signal. The second voltage feedback circuit 1132 feeds back the voltage output by the second voltage output unit 1131 to the controller 121. The controller 121 adjusts the pulse signal output to the second voltage output unit 1131 according to the feedback voltage value, so that the second voltage output unit 1131 outputs a voltage. The voltage is stabilized at 15V, so a smaller current flows through the switch tube 2000 under the 15V pulse signal. At this time, the controller 121 increases the pulse width of the pulse signal based on the first preset pulse width according to the peak current flowing through the switch tube 2000 under test, so as to slowly increase the current flowing through the switch tube 2000 under test. When the controller 121 detects that the peak current flowing through the switch tube 2000 under test reaches the first preset current value, the pulse signal of the second preset pulse width is applied to the switch tube 2000 under test, thereby testing the switch tube 2000 under test.

[0109] Therefore, this embodiment can combine the adjustment of the driving voltage of the tested switch tube 2000 with the test mode. In a specific test scenario, multiple test modes can be further expanded by adjusting the driving voltage applied to the tested switch tube 2000, which is beneficial to testing the overcurrent capability of the tested switch tube 2000 under different driving voltages in a specific test scenario, thereby facilitating a more comprehensive test of the tested switch tube 2000, and further facilitating a more comprehensive evaluation of the switching performance of the tested switch tube 2000.

[0110] As another embodiment of the present invention, an embodiment of the present invention provides a circuit board, which includes the switch tube test circuit described above. The circuit board can be an independent circuit board or a circuit board composed of multiple circuit boards.

[0111] Finally, it should be noted that the present invention can be implemented in many different forms and is not limited to the embodiments described in this specification. These embodiments do not serve as additional limitations on the content of the present invention. The purpose of providing these embodiments is to provide a more thorough and comprehensive understanding of the disclosure of the present invention. In addition, under the concept of the present invention, the above-mentioned technical features can continue to be combined with each other, and there are many other variations of the different aspects of the present invention as described above, all of which are considered to be within the scope of the description of the present invention. Furthermore, it is obvious to those skilled in the art that improvements or modifications can be made based on the above description, and all such improvements and modifications should fall within the scope of protection of the claims appended to the present invention.

Claims

1. A switch tube test circuit, characterized in that: include: A power supply circuit is used to provide the voltage required for the switch tube test; A test main circuit, comprising an auxiliary switch tube, the auxiliary switch tube is electrically connected to the power supply circuit, and the test main circuit is used to access the switch tube under test; A current sampling circuit, which is used to be electrically connected to the switch tube under test and can sample the current flowing through the switch tube under test; The control circuit is used to be electrically connected to the power supply circuit, the auxiliary switch tube, the switch tube under test and the current sampling circuit respectively. According to a specified test mode, the passive switch tube can be controlled to be in an on state, and in the specified test mode, the active switch tube can be controlled to be on and off according to the current flowing through the switch tube under test to test the switch tube under test. When the active switch tube is the switch tube under test, the passive switch tube is the auxiliary switch tube, and when the active switch tube is the auxiliary switch tube, the passive switch tube is the switch tube under test.

2. The switch tube test circuit according to claim 1, characterized in that: The specified test mode includes a pulse current test mode; In the pulse current test mode, the control circuit controls the passive switch tube to be in the on state, and applies a pulse signal of a first preset pulse width to the active switch tube. According to the current flowing through the switch tube under test, the pulse width of the pulse signal is increased on the basis of the first preset pulse width to raise the current flowing through the switch tube under test. When the control circuit detects that the peak value of the current reaches the first preset current value, a pulse signal of a second preset pulse width is applied to the active switch tube.

3. The switch tube test circuit according to claim 2, characterized in that: The pulse current test mode includes an active test mode and a passive test mode; When the pulse current test mode is the active test mode, the passive switch tube is the auxiliary switch tube, and the active switch tube is the switch tube under test; When the pulse current test mode is the passive test mode, the passive switch tube is the switch tube under test, and the active switch tube is the auxiliary switch tube.

4. The switch tube test circuit according to claim 1, characterized in that: The specified test mode includes a constant current test mode; In the constant current test mode, the control circuit controls the switch tube under test to be in the on state, and applies a pulse signal of a third preset pulse width to the auxiliary switch tube. According to the current flowing through the switch tube under test, the pulse width of the pulse signal is increased on the basis of the third preset pulse width to raise the current flowing through the switch tube under test. When it is detected that the effective value of the current reaches the second preset current value, a pulse signal of a fourth preset pulse width is applied to the auxiliary switch tube.

5. The switch tube test circuit according to claim 1, characterized in that: The test main circuit also includes: a current limiting circuit, electrically connected to the auxiliary switch tube and the switch tube under test, respectively, and used for storing energy to limit the current flowing through the auxiliary switch tube or the switch tube under test; The freewheeling circuit is used to be electrically connected to the current limiting circuit, the auxiliary switch tube and the switch tube under test respectively, and is used to provide a freewheeling path when the current limiting circuit releases energy.

6. The switch tube test circuit according to claim 1, characterized in that: The power supply circuit comprises: a first voltage detection circuit, configured to be electrically connected to the auxiliary power supply and the control circuit, and configured to detect the voltage of the auxiliary power supply; A storage circuit, electrically connected to the test main circuit; a second voltage detection circuit, electrically connected to the energy storage circuit and the control circuit, respectively, and used for detecting the voltage of the energy storage circuit; A charging circuit, electrically connected to the energy storage circuit and the control circuit, respectively, and the charging circuit can form a pre-charging path and a direct charging path with the energy storage circuit respectively; When the control circuit detects that the voltage of the auxiliary power supply reaches a first preset voltage value, the pre-charging path is enabled to charge the energy storage circuit. When the control circuit detects that the voltage of the energy storage circuit reaches a second preset voltage value, the direct charging path is enabled to charge the energy storage circuit.

7. The switch tube test circuit according to claim 1, characterized in that: The control circuit comprises: A controller, which can output a first control signal, a second control signal, a third control signal and a fourth control signal in response to the specified test mode; a first driving circuit, electrically connected to the controller and the auxiliary switch tube, respectively, for responding to the first control signal to control the on and off of the auxiliary switch tube, and responding to the third control signal to control the driving voltage applied to the auxiliary switch tube; The second driving circuit is electrically connected to the controller and the switch tube under test respectively, and is used to respond to the second control signal to control the on and off of the switch tube under test, and respond to the fourth control signal to control the driving voltage applied to the switch tube under test.

8. A circuit board, characterized in that: It comprises a switch tube test circuit as described in any one of claims 1 to 7.

9. A test fixture, characterized in that: Comprising the circuit board as claimed in claim 8.

10. A testing system, characterized in that: include: The test fixture as claimed in claim 9; an auxiliary power supply, electrically connected to the test fixture and used to supply power to the test fixture; as well as An electronic device is communicatively connected with the test fixture.

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