A magnetic latching relay testing device adapted for multi-drive chips

Abstract

This invention, entitled "A Testing Device for Magnetic Latching Relays Adapted to Multiple Driver Chips," belongs to the field of relay testing technology. The technical problems it aims to solve are: poor versatility, low measurement accuracy, and low work efficiency of existing products. The key technical points are: the device includes a main control unit, a relay drive unit, a temperature and humidity acquisition unit, a display unit, a serial communication unit, a power supply unit, external control terminals, an external feedback terminal, and a jumper selection circuit; the power supply unit supplies power to the relay drive unit, main control unit, temperature and humidity acquisition unit, display unit, and serial communication unit; the main control unit is communicatively connected to the serial communication unit and drives the temperature and humidity acquisition unit and the display unit; the main control unit outputs control signals to the relay drive unit, which, after being switched by the jumper selection circuit, are connected to the external control terminal, connecting to the magnetic latching relay under test; the magnetic latching relay under test sends its action signal back to the main control unit through the external feedback terminal, completing the time acquisition.

Description

Technical Field

[0001] This invention relates to the field of relay testing technology, and more specifically to a magnetic latching relay testing device adapted to multiple driver chips. Background Technology

[0002] In smart meters, to achieve the zero-crossing opening and closing function, the precise operating time of the magnetic latching relay is required. This allows the controller to send a drive signal in advance, compensating for the mechanical delay of the relay itself. Before mass production of smart meters, the opening and closing operating times of the magnetic latching relays, which are not yet soldered or assembled onto the meter's circuit board, must be tested individually. Based on the measured operating time parameters, the meter's main control program is optimized, thereby achieving precise opening and closing control of the entire meter near the zero-crossing point.

[0003] For example, the relevant patent documents retrieved: CN122017541A discloses a method and apparatus for measuring relay operating time and automatically verifying test results, comprising the following steps: determining the type and key parameters of the relay under test, and configuring its input trigger conditions; synchronously acquiring the relay's input trigger signal, output state voltage, and mechanical contact state through multiple channels, and performing timestamp correction and preprocessing on the acquired signals to obtain multi-feature operating time information; and calculating the relay's operating time based on the multi-feature operating time information. This invention achieves accurate measurement of operating time in complex environments by performing high-precision synchronous acquisition of the relay's input trigger signal, output state voltage, output state current, and mechanical contact state, and combining this with weighted fusion of multi-feature operating time information.

[0004] CN104977528A discloses a device for detecting the operating time and reset time of a magnetic latching relay. Since the manual for magnetic latching relays does not provide precise operating and reset times, and in applications where these two parameters must be accurate, this invention proposes using the grid voltage synchronization signal as a reference. A microcontroller is used to measure the time difference between the start of the driving voltage applied to the magnetic latching relay and the moment the relay closes or closes to determine the operating or reset time, and these two times are displayed on an LCD screen. This solution is mainly used in smart meter zero-crossing circuit breaker scenarios.

[0005] The prior art represented by the aforementioned documents has at least the following unresolved technical problems or defects: 1. Conventional test fixtures have fixed drive circuits, and a single device can only be adapted to a single type of drive chip. The three drive chips CN8033SHR, CN8031TSR, and AL868, which are the mainstream in mass production of electricity meters in the industry, cannot be compatible at the same time. Testing relays with different drive chips requires replacing the entire set of fixtures, resulting in poor product versatility. 2. Traditional fixtures do not have external independent wiring terminals. The components under test need to be soldered on the PCB (Printed Circuit Board) of the meter for testing. They cannot be used to test independent bare magnetic latching relays. In addition, the fixtures are too large and the operation is too cumbersome. 3. The simple tooling commonly used in the market adopts a software cyclic timing scheme. The timing value is easily affected by the microcontroller program scheduling, making it difficult to accurately capture the transition edge of the relay contact level. The measurement accuracy cannot meet the calibration standard of the zero-crossing control parameter of the meter. 4. Traditional tooling does not have the function of synchronously collecting ambient temperature and humidity. Fluctuations in ambient temperature and humidity will change the driving response speed of the magnetic latching relay coil. Without environmental data, it is difficult to analyze the causes of changes in device performance. At the same time, the test data is only displayed locally, and large-scale sampling inspections rely on manual data copying, resulting in low work efficiency.

[0006] To address the shortcomings of the existing technology, it is necessary to design a magnetic latching relay for unwelded applications that can be independently tested, allowing for component performance screening before assembly and the collection of precise action time data. This would provide measured data support for parameter calibration of the smart meter's zero-crossing opening and closing control program. Summary of the Invention

[0007] The purpose of this invention is to provide: A testing device for magnetic latching relays compatible with multiple driver chips is disclosed. It is simultaneously compatible with various driver chips such as CN8033SHR, CN8031TSR, and AL868, achieving rapid adaptation through pluggable driver chip sockets and jumper switching. By setting independent external control and feedback terminals, it can directly test bare, unsoldered magnetic latching relays. A hardware timer combined with external interrupt triggering method accurately captures the contact level edges, ensuring timing accuracy. An environmental parameter acquisition unit collects environmental parameters, and a serial communication unit automatically exports test data, enabling traceable and analyzable batch test data. This allows for component performance screening before meter assembly, collecting precise action time data, and providing reliable measured data support for parameter calibration of the smart meter's zero-crossing opening and closing control program.

[0008] Terminology Explanation: Unless otherwise defined, all technical terms herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0009] It should be understood that the above brief description and the following detailed description are exemplary and for illustrative purposes only, and do not limit the subject matter of the invention in any way. In this invention, the singular is used in conjunction with the plural unless otherwise specifically stated. It should also be noted that, unless otherwise stated, the use of “or” or “or” means “and / or”. Furthermore, the use of the term “comprising” and other forms such as “including,” “containing,” and “contains” are not limiting.

[0010] Unless otherwise stated, conventional methods within the scope of the art shall be used.

[0011] Unless specifically defined herein, the use of all commercially available products herein employs standard techniques. For example, it may be carried out using the manufacturer's instructions for use with the kit, or in accordance with methods known in the art or the description of this invention. The techniques and methods described herein can generally be implemented according to conventional methods well known in the art, based on the descriptions in the various summary and more specific documents cited and discussed in this specification.

[0012] The terms “optional / arbitrary” or “optionally / arbitrarily” mean that the event or situation described below may or may not occur, including both the occurrence and non-occurrence of the event or situation.

[0013] The term "magnetic latching relay" as used in this article refers to a new type of relay that uses permanent magnets to maintain the state of the contacts, belonging to automatic switching devices.

[0014] The term "GPIO interface" used in this article refers to a general purpose input / output port.

[0015] The term "IIC" used in this article refers to the integrated circuit bus, or Inter-Integrated Circuit in English.

[0016] The term "UART" used in this article refers to Universal Asynchronous Receiver / Transmitter.

[0017] The term "LDO" used in this article refers to Low Dropout Regulator.

[0018] In a first aspect, the present invention provides: A magnetic latching relay testing device adapted to multiple driver chips includes a main control unit, a relay driver unit, a temperature and humidity acquisition unit, a display unit, a serial communication unit, a power supply unit, an external control terminal, an external feedback terminal, and a jumper selection circuit. The power supply unit supplies power to the relay driver unit, main control unit, temperature and humidity acquisition unit, display unit, and serial communication unit. The main control unit is bidirectionally connected to the serial communication unit and simultaneously drives the temperature and humidity acquisition unit and the display unit. The main control unit outputs a control signal to the relay driver unit, which, after being switched by the jumper selection circuit, is connected to the external control terminal, which in turn connects to the magnetic latching relay under test. The magnetic latching relay under test sends an action signal back to the main control unit through the external feedback terminal, completing the time acquisition.

[0019] Based on further solutions to the technical problems of the present invention, or simultaneous solutions to multiple technical problems, the preferred solution in the technical solution provided in the first aspect of the present invention includes: First preferred option: The power supply unit splits into two power sources: one 12V supply to the relay drive unit, and the other 5V to 3.3V via an LDO voltage regulator chip, which provides unified power to the main control unit, serial communication unit, temperature and humidity acquisition unit, and display unit.

[0020] Second preferred option: The relay drive unit integrates a drive chip, and the control input terminals of all drive chips are connected to the same set of GPIO interfaces of the main control unit; wherein, the drive chip includes one or more of CN8033SHR, CN8031TSR, and AL868 drive chips; By integrating the driver chip required for the electricity meter and sharing the control pins of the main control unit, the working chip can be switched by relying on jumper caps; an independent external control terminal is brought out, which can directly connect to and test the magnetic latching relay that is not connected to the circuit and is not soldered on the electricity meter board, making the measurement operation convenient and simple.

[0021] Third preferred option: The main control unit integrates a hardware timer and multiple external interrupt pins. The hardware timer is used for timing, and the timing is started and stopped when the external interrupt captures the contact status. By using hardware timing, software timing errors are avoided, and the measurement accuracy meets the calibration of the meter's zero-crossing and opening / closing parameters.

[0022] Fourth preferred option: The display unit uses an OLED display screen, which is connected to the display interface of the main control unit. Data uploaded is displayed locally in real time on the OLED display screen, eliminating the need for manual recording and making it suitable for measuring the actuation time of large batches of magnetic latching relays on production lines.

[0023] Fifth preferred option: The serial communication unit establishes a UART link and communicates with an external computer terminal serial port assistant.

[0024] Sixth preferred option: The output terminal of the selected drive via the jumper selection circuit is connected to an external control terminal. The external control terminal is used to connect the control line of the bare magnetic latching relay to transmit control signals and control the magnetic latching relay to operate.

[0025] Seventh preferred option: The external control terminal is connected in parallel with sockets matching different types of relays, which are plugged in and unplugged during testing; Furthermore, the external feedback terminal is connected to the magnetic latching relay under test via a feedback signal line, which is ultimately connected to the external interrupt IO pin of the main control unit to collect the level changes caused by the on / off state of the contacts in real time.

[0026] Compared with the prior art, the present invention has at least the following beneficial effects: 1. The device of this invention is compatible with various mainstream driver chips such as CN8033SHR, CN8031TSR, and AL868, achieving rapid adaptation through pluggable chip sockets and jumper switching; it features independent external control and feedback terminals, allowing direct testing of unsoldered bare magnetic latching relays; it employs a hardware timer combined with external interrupt triggering to accurately capture contact level edges, ensuring timing accuracy; it synchronously collects environmental parameters through a temperature and humidity acquisition unit and automatically exports test data via serial port, enabling traceable and analyzable batch test data. This allows for component performance screening before meter assembly, collecting precise action time data, and providing reliable measured data support for parameter calibration of the smart meter's zero-crossing opening and closing control program.

[0027] 2. The main control unit in this invention uses a hardware timer and edge interrupt to trigger timing. Compared with traditional software timing fixtures, the delay measurement error is reduced from milliseconds to microseconds. The measured data can be directly used for the calibration of the zero-crossing circuit breaker program parameters of the smart meter, thus improving the measurement accuracy.

[0028] 3. The device of the present invention will not be falsely triggered. It is only allowed to detect contact changes and time when a drive pulse is issued and an external interrupt of the control terminal is triggered. When the external interrupt of the control terminal is not triggered, any contact signal of the feedback signal terminal is ignored, thus avoiding false test situations caused by power-on, human touch or external interference, and has stronger anti-interference ability.

[0029] 4. This invention directly tests magnetic latching relays that are not equipped with electricity meters by setting an independent external control terminal, achieving early detection and avoiding rework caused by assembling faulty relays into electricity meters; three drive jumper switching options are available, and a single tooling is compatible with the entire series of relay drive solutions for electricity meters, eliminating the need for multiple sets of testing equipment and making it more widely applicable.

[0030] 5. This invention synchronously collects and binds temperature and humidity with operating time, which can quantify the impact of ambient temperature and humidity on relay operating performance and improve data integrity.

[0031] 6. This invention allows users to view serial port uploaded data locally via an OLED display screen / directly export test data to Excel, eliminating the need for manual data transcription and enabling batch testing of magnetic latching relays, thus improving testing efficiency. Attached Figure Description

[0032] Figure 1 This is a diagram showing the signal transmission relationship of this device.

[0033] Figure 2 This is a flowchart of the testing process for this device. Detailed Implementation

[0034] The following non-limiting embodiments are intended to enable those skilled in the art to gain a more comprehensive understanding of the present invention, but do not limit the invention in any way. The following content is merely an exemplary description of the scope of protection claimed by the present invention, and those skilled in the art can make various changes and modifications to the present invention based on the disclosed content, and such changes should also fall within the scope of protection claimed by the present invention.

[0035] The present invention will be further described below by way of specific embodiments. Unless otherwise specified, all instruments, devices, equipment, products, etc., used in the embodiments of the present invention are obtained through conventional commercial means.

[0036] Example 1 Reference Figure 1As shown, this embodiment provides a magnetic latching relay testing device adapted to multiple driver chips, used to measure the pull-in and release times of the magnetic latching relay. Specifically, the testing device includes a main control unit, a relay drive unit, a temperature and humidity acquisition unit, a display unit, a serial communication unit, a power supply unit, an external control terminal, an external feedback terminal, and a jumper selection circuit. The power supply unit supplies power to the relay drive unit, main control unit, temperature and humidity acquisition unit, display unit, and serial communication unit. The power supply unit has two power sources: one 12V supply to the relay drive unit, and the other, after being stepped down from 5V to 3.3V via an LDO voltage regulator chip, supplies power to the main control unit, serial communication unit, temperature and humidity acquisition unit, and display unit. The main control unit has bidirectional communication with the serial communication unit and simultaneously drives the temperature and humidity acquisition unit and the display unit. The main control unit outputs a control signal to the relay drive unit, which, after being switched by the jumper selection circuit, is connected to the external control terminal, connecting to the coil of the magnetic latching relay under test. The contacts of the magnetic latching relay under test send the action signal back to the main control unit through the external feedback terminal, completing the time acquisition.

[0037] In this embodiment, the main control unit uses the FM33LE0x6 microcontroller, which integrates a hardware timer, multiple external interrupt pins, etc. This hardware timer enables high-precision timing, and the external interrupt captures the contact state to start and stop the timing. It should be noted that other microcontrollers with similar functions can also be used instead of the FM33LE0x6 microcontroller.

[0038] In this embodiment, the relay driving unit integrates multiple driving chips, and the control input terminals of these multiple driving chips are connected to the same set of GPIO interfaces of the main control unit. The GPIO interfaces are configured in push-pull output mode, without internal pull-up or pull-down resistors. Preferably, three general-purpose driving chips, CN8033SHR, CN8031TSR, and AL868, are integrated. The power supply pins and output pins of these three driving chips are respectively connected to the power supply pins and output pins of the corresponding jumper selection circuit. By inserting and removing the jumper cap in the jumper selection circuit, the power supply and output path of any one driving chip can be selected. The unselected driving chip is powered off and its output is cut off. By inserting and removing the jumper cap, a single driving chip can be selected to work, and the remaining two output circuits and power supply are disconnected. That is, this embodiment mounts three driving chips, CN8033SHR, CN8031TSR, and AL868, on the PCB circuit board and uses a jumper selection circuit to switch different driving paths to adapt to multiple specifications of magnetic latching relays.

[0039] In some other embodiments, the PCB circuit board can be soldered with any of the three driver chips, CN8033SHR, CN8031TSR, and AL868, depending on the product positioning. At the same time, the original jumper selection structure is eliminated, forming a dedicated test fixture for a single driver chip, which is only compatible with the magnetic latching relay model corresponding to the driver chip. The core test link of the overall main control, terminal wiring, and feedback timing is completely consistent with this embodiment.

[0040] In this embodiment, the temperature and humidity acquisition unit uses the SHT30 chip. The SHT30 chip communicates with the main control unit via IIC to acquire ambient temperature and humidity data in real time. It should be noted that the temperature and humidity acquisition unit can also be a digital temperature and humidity sensor of the same specification, such as the AHT20 or SHT20 chip, which uses IIC bus communication.

[0041] In this embodiment, the display unit uses an OLED display screen, which is connected to the display interface of the main control unit. It should be noted that conventional liquid crystal display devices such as segment LCDs and dot-matrix LCDs can also be used.

[0042] In this embodiment, the serial communication unit uses the CH340 chip. The CH340 chip establishes a UART link and communicates with an external computer terminal serial port assistant. It should be noted that the CH340 chip can be replaced with a similar USB-to-serial chip such as the CP2102.

[0043] In this embodiment, the power supply unit adopts a two-way independent power supply design: one is connected to an external 12V DC power supply to power multiple driver chips separately; the other is connected to a 5V voltage introduced from the USB serial port, which is stepped down to 3.3V by the LDO voltage regulator chip and then used to power the main control unit, temperature and humidity acquisition unit, display unit and serial communication unit.

[0044] In some other embodiments, the external 12V power input method is eliminated, and a DC-DC boost power module is added inside the tooling PCB circuit board. Only a 5V power supply is connected to the outside of the tooling. The input 5V voltage is boosted to 12V by the onboard DC-DC boost circuit before being sent to the relay drive unit. The final operating voltage of the drive chip is still maintained at the rated 12V to meet the drive conditions, and the architecture of the weak current 3.3V power supply branch remains unchanged.

[0045] In this embodiment, the output terminal of the selected driver is connected to an external control terminal via a jumper selection circuit. This external control terminal is used to connect the control line of a bare magnetic latching relay to transmit control signals and realize relay operation control. Multiple sockets matching different types of relays are connected in parallel at the external control terminal for convenient plugging and unplugging during testing.

[0046] In this embodiment, the external feedback terminal is connected to the feedback signal line of the magnetic latching relay under test, and the feedback signal line is finally connected to the external interrupt IO pin of the main control unit to collect the level change caused by the contact opening and closing in real time.

[0047] In this embodiment, the jumper selection circuit selects the power supply and output path of one of the driver chips by inserting or removing the jumper cap.

[0048] In other words, this device binds the enabling of the external interrupt at the feedback end to the drive triggering at the control end: the feedback end is only allowed to respond to the interrupt when the main control unit sends a drive pulse and then the external interrupt at the control end is triggered; the response is immediately disabled after the interrupt at the feedback end is processed, until the next drive pulse enables it again. When there is no drive, the level change at the feedback end is ignored, ensuring that only one valid action is recorded for each drive.

[0049] The testing principle of this device is as follows: Before testing, connect the magnetic latching relay control signal line to the external control terminal of the fixture, connect the feedback signal line to the external feedback terminal, and select and unplug the jumper cap of the corresponding circuit. After power-on initialization, the fixture is in standby mode.

[0050] After the device is powered on and initialized, the program periodically collects ambient temperature and humidity data and displays it in real time on the OLED screen. It waits for serial port commands from the host computer. The main control unit continuously monitors the serial port commands sent by the host computer. If no test command is received, it continues to collect temperature and humidity data in a loop.

[0051] The main control unit has a software flag bit, which is initially set to 0.

[0052] When a release command is received, the main control unit outputs a drive pulse and triggers an external interrupt, starts timer T1, and sets the software flag to 2. The magnetic latching relay under test performs a release action. The falling edge of the contact level triggers an interrupt (the first edge is used as the determination time of the action completion) to stop timer T1, reads the count value and converts it to units to obtain the release action time, and then clears the counter and the software flag to zero.

[0053] When a closing command is received, the main control unit outputs a pulse, triggers an interrupt to start timer T0, and sets the software flag to 1. After the magnetic latching relay under test closes, the rising edge of the contact triggers an interrupt (the first edge is used as the judgment time for the completion of the action) to stop timer T0, reads the count value and converts the unit to obtain the closing action time, and then clears the counter and the software flag to zero.

[0054] This device uses the first edge of the contact level as the completion time of the action, and the timing stops when an external interrupt is triggered. To ensure that interrupt response is only allowed after active driving, an interrupt enable flag is set: the flag is set when a drive pulse is output, and cleared after the interrupt processing is completed; the flag is 0 when there is no drive, and any change in contact level is ignored, thereby avoiding false triggering.

[0055] After the delay calculation for a single action is completed, the program collects the ambient temperature and humidity corresponding to this test, uploads the delay and temperature and humidity data to the host computer simultaneously, refreshes the data displayed on the OLED screen, and then the program returns to the instruction polling step to wait for the next test instruction.

[0056] The circuit breaker test results can be achieved using a dedicated relay circuit breaker test host computer. This host computer allows for setting the high-level pulse duration of the drive, making it convenient to modify the duration of the pulse when driving different relays without having to re-modify and reprogram the code. Furthermore, the host computer allows for setting the number of test cycles, eliminating the need for repeated manual command sending, and it also has the function of directly exporting test data to Excel, making the testing process more convenient and efficient.

[0057] The circuit breaker test can also be performed by sending commands through a regular serial port assistant; however, compared to the externally compatible relay circuit breaker test host computer, it lacks the functions of setting the high-level pulse duration, setting the number of cyclic tests, and directly exporting test data to Excel.

[0058] In other words, this PCB circuit board can be tested via a host computer that includes a relay for opening and closing. This allows for setting the high-level pulse duration of the drive, making it convenient to modify the duration of different relays without having to re-program the code. Furthermore, the host computer can be used to set the number of test cycles, eliminating the need for repeated manual command sending, and it also has the function of directly exporting test data to Excel, making the testing process more convenient and efficient.

[0059] The test results of this device are shown in Table 1 below: Table 1

[0060] Finally, it should be noted that the above content is only used to illustrate the technical solution of the present invention, and is not intended to limit the scope of protection of the present invention. Simple modifications or equivalent substitutions made by those skilled in the art to the technical solution of the present invention do not depart from the essence and scope of the technical solution of the present invention.

Claims

1. A testing device for a magnetic latching relay adapted to multiple driver chips, characterized in that, It includes a main control unit, a relay drive unit, a temperature and humidity acquisition unit, a display unit, a serial communication unit, a power supply unit, external control terminals, external feedback terminals, and a jumper selection circuit; The power supply unit provides power to the relay drive unit, main control unit, temperature and humidity acquisition unit, display unit, and serial communication unit. The main control unit has a bidirectional communication connection to the serial communication unit and simultaneously drives the temperature and humidity acquisition unit and the display unit. The main control unit outputs control signals to the relay drive unit, which are then switched via a jumper selection circuit and connected to an external control terminal to connect to the magnetic latching relay under test. The magnetic latching relay under test sends the action signal back to the main control unit through an external feedback terminal to complete the time acquisition.

2. The magnetic latching relay testing device adapted to multiple driver chips according to claim 1, characterized in that, The power supply unit splits into two power sources: one 12V supply to the relay drive unit, and the other 5V to 3.3V via an LDO voltage regulator chip, which provides unified power to the main control unit, serial communication unit, temperature and humidity acquisition unit, and display unit.

3. The magnetic latching relay testing device adapted to multiple driver chips according to claim 1, characterized in that, The relay drive unit integrates a drive chip, and the control input terminals of all drive chips are connected to the same set of GPIO interfaces of the main control unit.

4. The magnetic latching relay testing device adapted to multiple driver chips according to claim 3, characterized in that, The driver chip includes one or more of CN8033SHR, CN8031TSR, and AL868 driver chips.

5. A magnetic latching relay testing device adapted to multiple driver chips according to claim 1, characterized in that, The main control unit integrates a hardware timer and multiple external interrupt pins. The hardware timer is used for timing, and the timing is stopped when the external interrupt capture contact status is detected.

6. The magnetic latching relay testing device adapted to multiple driver chips according to claim 1, characterized in that, The display unit uses an OLED display screen, which is connected to the display interface of the main control unit.

7. A magnetic latching relay testing device adapted to multiple driver chips according to claim 1, characterized in that, The serial communication unit establishes a UART link and communicates with an external computer terminal serial port assistant.

8. A magnetic latching relay testing device adapted to multiple driver chips according to claim 1, characterized in that, The output terminal of the selected drive via the jumper selection circuit is connected to an external control terminal. The external control terminal is used to connect the control line of the bare magnetic latching relay to transmit control signals and control the magnetic latching relay to operate.

9. A magnetic latching relay testing device adapted to multiple driver chips according to claim 1, characterized in that, The external control terminal is connected in parallel with sockets matching different types of relays, which are plugged in and unplugged during testing.

10. A magnetic latching relay testing device adapted to multiple driver chips according to claim 1, characterized in that, The external feedback terminal is connected to the magnetic latching relay under test via a feedback signal line, which is ultimately connected to the external interrupt IO pin of the main control unit to collect the level changes caused by the on / off state of the contacts in real time.

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