Automatic tool test circuit and test method based on super capacitor

Abstract

The invention relates to an automatic tool test circuit and test method based on a super capacitor. The automatic tool test circuit comprises a control unit, a switch S3, a super capacitor C16, a resistor R57, a current-limiting resistor R35, a resistor R56 and a to-be-tested module. The control unit is used for controlling on and off of the switch S3; the positive electrode of the super capacitor C16 is sequentially connected with a resistor R57, a switch S3 and a resistor R56 in series, and the negative electrode of the super capacitor C16 is grounded; the module to be tested comprises a sampling resistor R34 used for detecting an overcurrent and generating a voltage difference; the first end of the sampling resistor R34 is connected with the second end of the resistor R56, and the second end of the sampling resistor R34 is grounded; the super capacitor C16 is used for storing electric energy and providing current at the moment of discharging, the super capacitor C16 discharges at the moment of closing of the switch S3, and instantaneous current is generated on the sampling resistor R34. The method is low in cost, safe, reliable and easy to implement in factory flow line production, and remarkable competitive advantages are provided for enterprises.

Description

Technical Field

[0001] This invention relates to the field of circuit protection device technology, specifically to an automated tooling test circuit and test method based on a supercapacitor. Background Technology

[0002] In the design and production of frequency converter control boards, verifying the motor overcurrent protection circuit is a crucial step in ensuring product quality and reliability. As the core device for motor control, the performance of the frequency converter directly affects the stable operation and lifespan of the motor. During frequency converter operation, if an abnormality such as a short circuit occurs in the frequency converter output circuit, excessive current may damage critical components in the circuit and even cause a safety accident. Therefore, the motor overcurrent protection circuit on each PCBA (Printed Circuit Board Assembly) board needs to undergo rigorous verification to ensure that the protection mechanism can be triggered promptly under extreme conditions to prevent circuit damage.

[0003] Traditional verification methods typically rely on expensive current source devices to generate the required trigger current. However, the sampling resistors used on inverter control boards are often only a few milliohms, while the trigger current required by the verification circuit can reach tens, hundreds, or even hundreds of amperes. Such current requirements make the purchase and maintenance of high-current source devices extremely costly, undoubtedly a heavy burden for most companies. Furthermore, the limited variety of current source devices currently available on the market that can provide such high currents further increases the difficulty and cost of procurement for businesses.

[0004] Therefore, those skilled in the art urgently need to develop a new technical solution to address the above problems. Summary of the Invention

[0005] To overcome the problems existing in related technologies, this invention discloses an automated tooling test circuit and test method based on supercapacitors.

[0006] According to a first aspect of the present invention, an automated tooling test circuit based on a supercapacitor is provided. The automated tooling test circuit includes: a control unit, a switch S3, a supercapacitor C16, a resistor R57, a current-limiting resistor R35, a resistor R56, and a module to be tested.

[0007] The control unit is electrically connected to the switch S3 and is used to control the closing and opening of the switch S3;

[0008] The positive terminal of the supercapacitor C16 is connected in series with the first terminal of the resistor R57, the second terminal of the resistor R57, the switch S3, the first terminal of the resistor R56, and the second terminal of the resistor R56. The negative terminal of the supercapacitor C16 is grounded. The first terminal of the current-limiting resistor R35 is connected in the series circuit between the second terminal of the resistor R57 and the switch S3. The second terminal of the current-limiting resistor R35 is connected to a 5V voltage source.

[0009] The module to be tested includes: a sampling resistor R34, used to detect overcurrent and generate voltage difference;

[0010] The first end of the sampling resistor R34 is connected to the second end of the resistor R56, and the second end is grounded;

[0011] The supercapacitor C16 is used to store electrical energy and provide current at the moment of discharge. At the moment the switch S3 is closed, the supercapacitor C16 discharges, and an instantaneous current is generated on the sampling resistor R34.

[0012] Optionally, the module under test may further include: a comparator and an MCU unit;

[0013] The negative terminal of the comparator is connected to the first terminal of the sampling resistor R34, and is used to detect the voltage difference between the first and second terminals of the sampling resistor R34 and output a protection signal.

[0014] The MCU unit is connected to the comparator and is used to receive the protection signal output by the comparator and trigger overcurrent protection action according to the protection signal.

[0015] Optionally, the comparator is connected to the interrupt pin of the MCU.

[0016] Optionally, the resistor R57 is the equivalent internal resistance of the supercapacitor C16.

[0017] Optionally, the resistor R56 is an equivalent contact resistance, and the resistance value of the resistor R56 is the sum of the first equivalent contact resistance value and the second equivalent contact resistance value. The first equivalent resistance value is the equivalent contact resistance of the switch S3, and the second equivalent resistance value is the equivalent contact resistance of the contact point between the module under test and the test resistor of the tooling.

[0018] Optionally, the switch S3 is an electronic switch, and the closing and opening of the switch S3 is controlled by the control unit or a programmable signal source to achieve automated repeated triggering test.

[0019] Optionally, the module to be tested is an overcurrent protection circuit integrated on the PCBA board.

[0020] According to a second aspect of the embodiments disclosed in this invention, a testing method for an automated tooling test circuit based on a supercapacitor is provided, applied to the automated tooling test circuit described in the first aspect of the embodiments disclosed in this invention, the method comprising:

[0021] Charge the supercapacitor C16 to a preset voltage value;

[0022] Close the switch S3 to discharge the supercapacitor C16, thereby generating a transient current across the sampling resistor R34;

[0023] The comparator detects the voltage difference between the first and second terminals of the sampling resistor R34 and outputs a protection signal.

[0024] The MCU unit receives the protection signal and determines whether the overcurrent protection circuit is working properly based on the protection signal. If it is not working properly, the overcurrent protection action is triggered.

[0025] Repeat the above steps to achieve automated batch testing.

[0026] Optionally, the test method is applied to the production line of the frequency converter control board.

[0027] In summary, this invention relates to an automated tooling test circuit and method based on a supercapacitor. The automated tooling test circuit includes: a control unit, a switch S3, a supercapacitor C16, a resistor R57, a current-limiting resistor R35, a resistor R56, and a module under test. The control unit controls the closing and opening of the switch S3. The positive terminal of the supercapacitor C16 is connected in series with the resistor R57, the switch S3, and the resistor R56, while the negative terminal of the supercapacitor C16 is grounded. The module under test includes: a sampling resistor R34, used to detect overcurrent and generate a voltage difference. The first end of the sampling resistor R34 is connected to the second end of the resistor R56, and the second end is grounded. The supercapacitor C16 stores electrical energy and provides current during discharge. At the instant the switch S3 is closed, the supercapacitor C16 discharges, generating a momentary current in the sampling resistor R34. This method is not only low-cost and reliable but also easy to implement in factory assembly line production, providing enterprises with a significant competitive advantage.

[0028] Other features and advantages disclosed in this invention will be described in detail in the following detailed description section. Attached Figure Description

[0029] The accompanying drawings are provided to further illustrate the present disclosure and form part of the specification. They are used together with the following detailed description to explain the present disclosure, but do not constitute a limitation thereof. In the drawings:

[0030] Figure 1This is a schematic diagram of an automated tooling test circuit based on a supercapacitor, according to an exemplary embodiment.

[0031] Figure 2 It is based on Figure 1 A simulation diagram of an automated tooling test circuit based on a supercapacitor is shown.

[0032] Figure 3 This is a flowchart illustrating a test method for an automated tooling test circuit based on a supercapacitor, according to an exemplary embodiment. Detailed Implementation

[0033] The specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit the scope of the present disclosure.

[0034] This invention proposes an automated tooling test circuit and method based on supercapacitors. It utilizes the large current generated by the supercapacitor during discharge to simulate the current surge under actual short-circuit conditions, thereby effectively verifying the overcurrent protection circuit of the motor. This method is not only low-cost and reliable, but also easy to implement in factory assembly line production, providing enterprises with a significant competitive advantage.

[0035] Figure 1 This is a schematic diagram illustrating the structure of an automated tooling test circuit based on a supercapacitor, according to an exemplary embodiment. Figure 1As shown, the automated tooling test circuit includes: a control unit, a switch S3, a supercapacitor C16, a resistor R57, a current-limiting resistor R35, a resistor R56, and a module under test. The control unit is electrically connected to the switch S3 and is used to control the closing and opening of the switch S3. The positive terminal of the supercapacitor C16 is connected in series with the first end of the resistor R57, the second end of the resistor R57, the switch S3, the first end of the resistor R56, and the second end of the resistor R56. The negative terminal of the supercapacitor C16 is grounded. The first end of the current-limiting resistor R35 is connected in the series circuit between the second end of the resistor R57 and the switch S3. The second end of the current-limiting resistor R35 is connected to a 5V voltage source. The module under test includes: a sampling resistor R34, used to detect overcurrent and generate a voltage difference. The first end of the sampling resistor R34 is connected to the second end of the resistor R56, and the second end is grounded. The supercapacitor C16 is used to store electrical energy and provide current at the moment of discharge. At the moment the switch S3 is closed, the supercapacitor C16 discharges, and a momentary current is generated on the sampling resistor R34. The module under test also includes: a comparator and an MCU unit; the comparator is connected to the first end of the sampling resistor R34 and is used to detect the voltage difference between the first and second ends of the sampling resistor R34 and output a protection signal; the MCU unit is connected to the comparator and is used to receive the protection signal output by the comparator and trigger overcurrent protection action according to the protection signal.

[0036] Among them, resistor R57 is the equivalent internal resistance of supercapacitor C16. Resistor R56 is the equivalent contact resistance, and the resistance value of resistor R56 is the sum of the first equivalent contact resistance value and the second equivalent contact resistance value. The first equivalent resistance value is the equivalent contact resistance of switch S3, and the second equivalent resistance value is the equivalent contact resistance of the contact point between the module under test and the test resistor of the fixture.

[0037] Optionally, switch S3 is an electronic switch, and the closing and opening of switch S3 is controlled by a control unit or a programmable signal source to achieve automated repeated triggering test.

[0038] Optionally, the module to be tested is an overcurrent protection circuit integrated on the PCBA board.

[0039] For example, in a disclosed embodiment of the present invention, an automated test fixture circuit is constructed using a supercapacitor C16 to verify whether the motor overcurrent protection circuit of the frequency converter control board is functioning properly during large-scale production. At the instant the supercapacitor C16 discharges, a current of one hundred amperes or more is generated at the sampling resistor R34 of the overcurrent protection on the PCBA under test. Using this large current replaces expensive current source equipment, reducing production testing costs for enterprises.

[0040] Specifically, the circuits in the embodiments disclosed in this invention can be divided into test fixture circuits and PCBA internal circuits of the product under test (i.e., the module under test). For example... Figure 1As shown, the test fixture's ejector pins are connected at V1 and V3. R57 is the equivalent internal resistance of C16, R56 is the equivalent contact resistance between S3 and the ejector pin, C16 is a supercapacitor, R35 is a current-limiting resistor, and S3 is a switch.

[0041] After connecting the above circuit structure, charge the supercapacitor C16 to the preset voltage value. After the supercapacitor C16 is fully charged, close switch S3. At the instant the discharge begins (i.e., t=0), the supercapacitor C16 acts as a 5V voltage source. At this time, the current flowing through resistor R34 is V / R = 5V / (R57+R56+R34) = 5V / 0.022 ohms = 227A. The voltage difference generated by this current flowing through the sampling resistor R34 can be measured at V1. This voltage difference can be captured by the comparator circuit on the board under test and trigger an MCU interrupt, thereby determining whether the entire protection circuit is correct.

[0042] The VSQ3 is a GPIO or voltage source that can be programmably controlled by a microcontroller unit to repeatedly and automatically output a high-level square wave. By adjusting the frequency and duty cycle of the square wave via code, for example, triggering 10 times per second (10Hz), it can be set to continuously output a square wave for long-term, multi-cycle testing (such as aging tests). A high level is 5V (trigger switch S3 closes, supercapacitor discharges), and a low level is 0V (switch S3 opens, supercapacitor charges). Using this voltage source, PCBA boards can be automatically triggered for extended periods and multiple times during production, thereby reducing labor costs and making it more suitable for assembly line operations.

[0043] Preferably, the comparator is connected to the MCU's interrupt pin. This directly triggers the MCU interrupt via hardware, ensuring real-time protection action. The comparator output does not pass through the MCU's standard GPIO or ADC, but is directly connected to the interrupt pin (such as an external interrupt EXTI). This is because overcurrent can damage the circuit, requiring a response in milliseconds or even microseconds; ordinary software detection (such as cyclically reading the ADC) is too slow. Therefore, a very fast response speed (microseconds) is used to avoid the delay of software polling.

[0044] Simulation Verification: The control signal of the automated output switch S3 enables the production test to be in a state of long-term, multi-cycle automated repetitive aging test. As shown in Figure 2, the simulation generated repeatable pulses. When switch S3 is closed, a current greater than 100 amperes is generated at R34. Figure 2 As shown in Figure I(R34), this current generates a detectable voltage difference V1 at the sampling resistor R34. Figure 2 As shown in V1. After processing by the comparator, V1 generates a low-level transition that can be processed by the MCU. Figure 2 As shown in V2.

[0045] Figure 3 This is a flowchart illustrating a test method for an automated tooling test circuit based on a supercapacitor, according to an exemplary embodiment. The method is applied to automated tooling test circuits and includes:

[0046] In step 301, the supercapacitor C16 is charged to a preset voltage value.

[0047] In step 302, switch S3 is closed to discharge supercapacitor C16, thereby generating a transient current in sampling resistor R34.

[0048] In step 303, the voltage difference between the first and second terminals of the sampling resistor R34 is detected by a comparator and a protection signal is output.

[0049] In step 304, the MCU unit receives the protection signal and determines whether the overcurrent protection circuit is working properly based on the protection signal. If it is not working properly, the overcurrent protection action is triggered.

[0050] In step 305, the above steps are repeated to achieve automated batch testing.

[0051] Optionally, the test method is applied to the production line of the frequency converter control board.

[0052] Typically, the PCBA under test is positioned to the testing station via a conveyor belt, and the ejector pin automatically aligns with the sampling resistor R34 test point. The fixture's MCU controls the supercapacitor C16 to charge to 5V, and the voltage detection circuit confirms the completion of charging. The VSQ3 square wave signal is triggered, closing switch S3, causing C16 to discharge and generating an instantaneous current ≥100A across R34. The comparator circuit captures the overcurrent signal and triggers an interrupt in the PCBA's MCU, while the fixture records the protection response time. Based on the test results, the production line PLC automatically sorts qualified / unqualified products and generates a test report.

[0053] In summary, this invention relates to an automated tooling test circuit and method based on a supercapacitor. The automated tooling test circuit includes: a control unit, a switch S3, a supercapacitor C16, a resistor R57, a current-limiting resistor R35, a resistor R56, and a module under test. The control unit controls the closing and opening of the switch S3. The positive terminal of the supercapacitor C16 is connected in series with the resistor R57, the switch S3, and the resistor R56, while the negative terminal of the supercapacitor C16 is grounded. The module under test includes: a sampling resistor R34, used to detect overcurrent and generate a voltage difference. The first end of the sampling resistor R34 is connected to the second end of the resistor R56, and the second end is grounded. The supercapacitor C16 stores electrical energy and provides current during discharge. At the instant the switch S3 is closed, the supercapacitor C16 discharges, generating a momentary current in the sampling resistor R34. This method is not only low-cost and reliable but also easy to implement in factory assembly line production, providing enterprises with a significant competitive advantage.

[0054] The preferred embodiments of the present disclosure have been described in detail above with reference to the accompanying drawings. However, the present disclosure is not limited to the specific details of the above embodiments. Within the scope of the technical concept of the present disclosure, various simple modifications can be made to the technical solutions of the present disclosure, and these simple modifications all fall within the protection scope of the present disclosure.

[0055] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, this disclosure will not describe the various possible combinations separately.

[0056] Furthermore, various different embodiments of this disclosure can be combined in any way, as long as they do not violate the spirit of this disclosure, they should also be regarded as the content disclosed in this disclosure.

Claims

1. An automated tooling test circuit based on supercapacitors, characterized in that, The automated tooling test circuit includes: a control unit, a switch S3, a supercapacitor C16, a resistor R57, a current-limiting resistor R35, a resistor R56, and a module to be tested; The control unit is electrically connected to the switch S3 and is used to control the closing and opening of the switch S3; The positive terminal of the supercapacitor C16 is connected in series with the first terminal of the resistor R57, the second terminal of the resistor R57, the switch S3, the first terminal of the resistor R56, and the second terminal of the resistor R56. The negative terminal of the supercapacitor C16 is grounded. The first terminal of the current-limiting resistor R35 is connected in the series circuit between the second terminal of the resistor R57 and the switch S3. The second terminal of the current-limiting resistor R35 is connected to a 5V voltage source. The module to be tested includes: a sampling resistor R34, used to detect overcurrent and generate voltage difference; The first end of the sampling resistor R34 is connected to the second end of the resistor R56, and the second end is grounded; The supercapacitor C16 is used to store electrical energy and provide current at the moment of discharge. At the moment the switch S3 is closed, the supercapacitor C16 discharges, and an instantaneous current is generated on the sampling resistor R34.

2. The automated tooling test circuit based on supercapacitors according to claim 1, characterized in that, The module to be tested also includes: a comparator and an MCU unit; The negative terminal of the comparator is connected to the first terminal of the sampling resistor R34, and is used to detect the voltage difference between the first and second terminals of the sampling resistor R34 and output a protection signal. The MCU unit is connected to the comparator and is used to receive the protection signal output by the comparator and trigger overcurrent protection action according to the protection signal.

3. The automated tooling test circuit based on supercapacitors according to claim 2, characterized in that, The comparator is connected to the interrupt pin of the MCU.

4. The automated tooling test circuit based on supercapacitors according to claim 2, characterized in that, The resistor R57 is the equivalent internal resistance of the supercapacitor C16.

5. The automated tooling test circuit based on supercapacitors according to claim 2, characterized in that, The resistor R56 is an equivalent contact resistance. The resistance value of the resistor R56 is the sum of the first equivalent contact resistance value and the second equivalent contact resistance value. The first equivalent resistance value is the equivalent contact resistance of the switch S3, and the second equivalent resistance value is the equivalent contact resistance of the contact point between the module under test and the test resistor of the tooling.

6. The automated tooling test circuit based on supercapacitors according to claim 2, characterized in that, The switch S3 is an electronic switch, and the closing and opening of the switch S3 is controlled by the control unit or programmable signal source to realize automated repeated triggering test.

7. The automated tooling test circuit based on supercapacitors according to claim 2, characterized in that, The module to be tested is an overcurrent protection circuit integrated on the PCBA board.

8. A testing method for an automated tooling test circuit based on a supercapacitor, characterized in that, The method, applied to the automated tooling test circuit according to any one of claims 2-7, comprises: Charge the supercapacitor C16 to a preset voltage value; Close the switch S3 to discharge the supercapacitor C16, thereby generating a transient current across the sampling resistor R34; The comparator detects the voltage difference between the first and second terminals of the sampling resistor R34 and outputs a protection signal. The MCU unit receives the protection signal and determines whether the overcurrent protection circuit is working properly based on the protection signal. If it is not working properly, the overcurrent protection action is triggered. Repeat the above steps to automate batch testing.

9. The test method for the automated tooling test circuit based on supercapacitors according to claim 8, characterized in that, The test method is applied to the production line of inverter control boards.

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