Low-thermal-electromotive-force scanning switch

Abstract

The invention relates to a low thermal electromotive force scanning switch, which belongs to the technical field of electric appliances and comprises a case, a main control module is arranged in the case, a power supply module is arranged on the main control module, a display module is arranged on the case, and a switch module penetrates through one side, deviating from the display module, of the case. An isolation module, a driving module and an interface module are sequentially arranged at the position, located in the machine box, of the switch module in the vertical direction, a communication module is arranged at the position, located on the switch module, of the machine box, and the power module, the communication module, the display module, the isolation module and the switch module are all electrically connected with the main control module. The isolation module, the driving module, the switch module and the interface module are electrically connected in sequence, and the main control module is used for sending a control signal to the isolation module. The control signal transmitted by the main control module is electrically isolated through the isolation module, so that the thermoelectric force can be effectively reduced, the working requirements of high-precision measurement and calibration are met, and the accuracy and reliability of related work are improved.

Description

Technical Field

[0001] The invention belongs to the technical field of electrical appliances, and in particular relates to a low thermal potential scanning switch. Background Art

[0002] High-precision measurement is crucial in modern electronic measurement technology. This is especially true in scenarios such as precision data acquisition systems for aircraft engine test benches, where even tiny thermoelectric potentials can cause significant deviations in measurement results, impacting the precise evaluation and control of equipment performance. With the continuous advancement of science and technology, the demand for measurement accuracy in various fields continues to rise. For example, key areas such as aerospace and scientific research require extremely high data accuracy and reliability. However, thermoelectric potentials, as an interference factor, have not been adequately addressed in existing scanning switch technology, making them unable to meet the requirements of high-precision measurement and calibration.

[0003] Traditional scanning switches fail to fully consider the impact of thermoelectric potentials during design. Even when measures are taken, it is difficult to reduce the thermoelectric potential to the level required for high-precision measurement. In many measurement systems, the accuracy of measurement results cannot be guaranteed due to the interference of thermoelectric potentials, making it impossible to accurately evaluate and control device performance. Specifically, traditional scanning switches have not been systematically optimized to address thermoelectric potential issues and lack effective means to reduce them, resulting in significant shortcomings in addressing thermoelectric issues. Summary of the Invention

[0004] In response to the above problems, the present invention provides a low thermal potential scanning switch, comprising a chassis, wherein a main control module is provided in the chassis, a power supply module is provided on the main control module, and a display module is provided on the chassis. A switch module is passed through the side of the chassis facing away from the display module, and the position of the switch module in the chassis is vertically provided with an isolation module, a drive module and an interface module. The chassis is provided with a communication module at the position of the switch module, and the power supply module, communication module, display module, isolation module and switch module are all electrically connected to the main control module. The isolation module, drive module, switch module and interface module are electrically connected in sequence. The main control module is used to send a control signal to the isolation module, and the isolation module is used to electrically isolate the control signal.

[0005] Furthermore, the isolation module includes a digital isolator, which is provided on the switch module and is electrically connected to the main control module.

[0006] Furthermore, the switch module includes several daughter card boards and relays, and the several daughter card boards are arranged in the chassis. The end of the daughter card board close to the inner wall of the chassis is provided with an interface module that penetrates the chassis. The digital isolator, relay and drive module are all arranged on the daughter card board, and the digital isolator, drive module, relay and interface module are electrically connected in sequence.

[0007] Furthermore, the driving module includes a driving chip, the driving chip is provided on the daughter card board, and the driving chip is electrically connected to the digital isolator.

[0008] Furthermore, the interface module includes a diode, a resettable fuse, a common terminal and a channel terminal group, the diode and the resettable fuse are both arranged on the daughter card board, the channel terminal group is electrically connected to the relay, the diode and the resettable fuse are both electrically connected to the common terminal, the diode and the resettable fuse are both electrically connected to the channel terminal group, and the common terminal and the channel terminal group are arranged in sequence vertically along the chassis.

[0009] Furthermore, the communication module includes a serial communication interface and a network communication interface. The serial communication interface and the network communication interface are vertically arranged in sequence at the position of the channel terminal group of the chassis. The serial communication interface and the network communication interface are both electrically connected to the main control module.

[0010] Furthermore, the main control module includes a main control motherboard, and the main control motherboard is provided with a power module, and the power module is used to supply power to the main control motherboard, communication module, display module, isolation module, drive module, switch module and interface module.

[0011] Furthermore, the power supply module includes a power conversion module and a power supply module. The power conversion module is arranged on the main control motherboard, and the power supply module is arranged on the chassis. The power supply module is electrically connected to the power conversion module.

[0012] Furthermore, the display module includes a liquid crystal display platform provided on the chassis, the liquid crystal display platform is electrically connected to the main control module, and the liquid crystal display platform is used to display a human-computer interaction interface.

[0013] Furthermore, an indicator light module is provided at a portion of the chassis close to the liquid crystal display platform, and the indicator light module is electrically connected to the switch module.

[0014] Compared with the prior art, the present invention has the following beneficial effects:

[0015] This invention electrically isolates control signals transmitted from the main control module through an isolation module, effectively reducing thermoelectric potentials (TEVs). This effectively meets the requirements of high-precision measurement and calibration, improving the accuracy and reliability of related operations. Compared to traditional scanning switches, this invention utilizes the connection between the isolation module, the main control module, and the driver module to achieve systematic optimization, thereby reducing the generation and impact of thermoelectric potentials. The isolation module can block interference from current, noise, and ground loops.

[0016] This invention utilizes N-channel MOS switches, a heat-sharing design, control circuit isolation, and complementary connections to successfully control thermoelectric potential to the nanovolt level within a standard laboratory environment and a temperature range of 10°C to 30°C. This effectively avoids measurement errors caused by thermoelectric potential interference in high-precision measurement scenarios, such as in-situ calibration of data acquisition devices on engine test benches, providing more accurate and reliable data for equipment performance evaluation and data analysis.

[0017] The main control module, power module, display module, isolation module, interface module and communication module of the present invention have clear functions and work together. The power module ensures stable power supply, the communication module realizes remote control, the isolation module reduces interference, the interface module enhances reliability, the display module provides a good interactive interface, the main control module accurately processes control signals, and the human-computer interaction interface is stable and functionally rich, which can make the low thermal potential scanning switch powerful and stable in performance, and has obvious advantages over the existing technology.

[0018] The chassis of the present invention adopts a mother-and-daughter board structural framework, namely a daughter card board and a main control motherboard, which can easily expand or adjust the number of channels according to actual needs. At the same time, it can quickly locate and replace faulty components during maintenance, effectively reducing maintenance costs and time. It is not only flexible and scalable, but also convenient for equipment maintenance.

[0019] Other features and advantages of the present invention will be described in the following description, and in part will become apparent from the description, or will be understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained by the structures pointed out in the description and the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following is a brief introduction to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0021] Figure 1 shows a schematic structural diagram of a low thermal potential scanning switch;

[0022] Figure 2 Shows a schematic diagram of the connection between the LCD display platform and the chassis;

[0023] Figure 3 Shows a schematic diagram of the connection between the interface module and the chassis;

[0024] Figure 4 Shows the flow chart of the low thermal potential scanning switch control signal;

[0025] Figure 5 A schematic diagram showing switch control information displayed on a liquid crystal display platform is shown;

[0026] Figure 6 A schematic diagram showing the display status query information of the liquid crystal display platform is shown;

[0027] Figure 7 A schematic diagram showing a liquid crystal display platform displaying remote setting information;

[0028] Figure 8 Shows a schematic diagram of the common terminal and nanovoltmeter circuit;

[0029] Figure 9 A circuit diagram showing a channel binding post group and a common binding post is shown.

[0030] Figure markings: 1. Chassis; 11. Indicator light module; 111. Channel indicator light; 2. Communication module; 21. Serial communication interface; 22. Network communication interface; 3. Power module; 31. Power conversion module; 32. Power supply module; 321. Grounding column; 322. Power switch and indicator light; 323. Fuse mounting seat; 324. Power socket; 4. Display module; 41. LCD display platform; 5. Main control module; 51. Main control motherboard; 6. Isolation module; 61. Digital isolator; 7. Driver module; 71. Driver chip; 72. N-channel MOS switch tube; 8. Switch module; 81. Daughter card board; 82. Relay; 9. Interface module; 91. Diode; 92. Resettable fuse; 93. Common terminal; 94. Channel terminal. DETAILED DESCRIPTION

[0031] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts shall fall within the scope of protection of the present invention.

[0032] Figure 1 Figure 2 shows the schematic diagram of the low thermal potential scanning switch. Figure 1As shown, a low thermal potential scanning switch includes a chassis 1, a main control module 5 is provided in the chassis 1, a power module 3 is provided on the main control module 5, a display module 4 is provided on the chassis 1, a switch module 8 is passed through the side of the chassis 1 away from the display module 4, the switch module 8 is located in the chassis 1 and is vertically provided with an isolation module 6, a drive module 7 and an interface module 9 in sequence, a communication module 2 is provided at the position of the switch module 8 of the chassis 1, the power module 3, the communication module 2, the display module 4, the isolation module 6 and the switch module 8 are all electrically connected to the main control module 5, and the isolation module 6, the drive module 7, the switch module 8 and the interface module 9 are electrically connected in sequence, Figure 4 The flow chart of the low thermal potential scanning switch control signal is shown in FIG. Figure 4 As shown, the main control module 5 is used to send a control signal to the isolation module 6, and the isolation module 6 is used to electrically isolate the control signal.

[0033] The low thermal potential scanning switch uses the isolation module 6 to electrically isolate the control signal transmitted by the main control module 5, which can effectively reduce the thermal potential, thereby meeting the working requirements of high-precision measurement and calibration, and improving the accuracy and reliability of related work.

[0034] Specifically, the size of the chassis 1 can be selected but is not limited to a 4U 19-inch standard chassis 1 .

[0035] Specifically, chassis 1 utilizes a motherboard-daughterboard structure, comprising daughter cards 81 and a main control motherboard 51. This allows for easy expansion or adjustment of the number of channels based on actual needs. Six daughter cards 81 are combined to create a 48-to-1 switch array. Furthermore, during maintenance, faulty components can be quickly located and replaced, effectively reducing maintenance costs and time. This flexibility and scalability facilitate equipment maintenance. A channel refers to a relay 82 and its corresponding channel terminal 94.

[0036] In some embodiments, the isolation module 6 includes a digital isolator 61, which is arranged on the switch module 8 and is electrically connected to the main control module 5; the digital isolator 61 can effectively isolate the thermoelectric potential in the control signal transmitted by the main control module 5 to the digital isolator 61, thereby reducing the impact of the thermoelectric potential on the switch module 8.

[0037] In some embodiments, the switch module 8 includes several daughter card boards 81 and relays 82, and several of the daughter card boards 81 are arranged in the chassis 1. The end of the daughter card board 81 close to the inner wall of the chassis 1 is provided with an interface module 9 that penetrates the chassis 1. The digital isolator 61, relay 82 and drive module 7 are all arranged on the daughter card board 81, and the digital isolator 61, drive module 7, relay 82 and interface module 9 are electrically connected in sequence; the daughter card board 81 provides setting conditions for the relay 82, digital isolator 61 and drive module 7; each daughter card board 81 is provided with a digital isolator 61, drive module 7 and relay 82, and the control signal is transmitted to the drive module 7 through the digital isolator 61, and the drive module 7 controls the action of the relay 82, which can block the interference of current, noise and ground loop; the interface module 9 is used to prevent the relay 82 from overvoltage and overcurrent.

[0038] In some embodiments, the driving module 7 includes a driving chip 71, which is provided on a daughter card board 81 and is electrically connected to the digital isolator 61; the driving chip 71 is used to receive control information isolated by the digital isolator 61, and use this control information to control the operation of the relay 82.

[0039] Specifically, the driver chip 71 is connected to the relay 82 through the N-channel MOS switch tube 72; after the digital isolator 61 isolates the thermoelectric potential in the electrical isolation control signal, the driver chip 71 sends a control signal to the N-channel MOS switch tube 72 to offset part of the thermoelectric potential again, so that the entire low thermoelectric potential scanning switch is within the temperature range of 10℃-30℃, and the thermoelectric potential can be controlled within the nV level, meeting the needs of high-precision measurement and calibration.

[0040] Specifically, the heat distribution design refers to symmetrically arranging the N-channel MOS switch tubes 72 to prevent the formation of a temperature gradient. This design is a prior art and will not be described in detail here.

[0041] Specifically, the complementary connection means that the driver chip 71 is connected to the relay 82 via the N-channel MOS switch tube 72 , wherein the N-channel MOS switch tube 72 can offset part of the thermoelectric potential again.

[0042] Figure 3 FIG. 1 shows a schematic diagram of the connection between the interface module 9 and the chassis 1. Figure 3 As shown, in some embodiments, the interface module 9 includes a diode 91, a resettable fuse 92, a common terminal 93 and a channel terminal group. The diode 91 and the resettable fuse 92 are both provided on the daughter card 81. Figure 9 Schematic diagram of the circuit of the channel terminal group and the common terminal 93 is shown, as shown in FIG. Figure 9As shown, the channel terminal group is electrically connected to the relay 82, the diode 91 and the resettable fuse 92 are both electrically connected to the common terminal 93, the diode 91 and the resettable fuse 92 are both electrically connected to the channel terminal group, and the common terminal 93 and the channel terminal group are arranged vertically in sequence along the chassis 1; the diode 91 is used to prevent the common terminal 93 and the channel terminal group from overvoltage; the resettable fuse 92 is used to prevent the common terminal 93 and the channel terminal group from overcurrent.

[0043] Specifically, Figure 9 The PPTC is a resettable fuse 92 , the TVS is a diode 91 , and the MOSFET is an N-channel MOS switch tube 72 . The anode of the diode 91 is connected to the channel terminal 94 , and the cathode of the diode 91 is connected to the N-channel MOS switch tube 72 .

[0044] Specifically, the chassis 1 is provided with at least six groups of channel binding posts, each group is provided with eight pairs of channel binding posts 94 , wherein a pair of channel binding posts 94 includes two channel binding posts 94 .

[0045] Specifically, at least six pairs of common binding posts 93 are provided on the chassis 1 . The six pairs of common binding posts 93 correspond to the six groups of channel binding posts 94 , respectively. The six pairs of common binding posts 93 are all electrically connected to the relay 82 .

[0046] Specifically, there are at least six daughter cards 81, and the six daughter cards 81 are arranged in the chassis 1. The six daughter cards are each provided with a relay 82, a digital isolator 61, a driver chip 71, a diode 91 and a resettable fuse 92. The diodes 91 and the resettable fuse 92 on the six daughter cards 81 are all electrically connected to the six groups of channel terminal groups; the digital isolators 61 on the six daughter boards can effectively isolate the thermoelectric potential in the control signal transmitted from the main control motherboard 51 to the digital isolator 61, thereby reducing the influence of the thermoelectric potential on the switch module 8.

[0047] In some embodiments, the communication module 2 includes a serial communication interface 21 and a network communication interface 22. The chassis 1 is located at the channel terminal group and is vertically provided with a serial communication interface 21 and a network communication interface 22. The serial communication interface 21 and the network communication interface 22 are both electrically connected to the main control module 5; the serial communication interface 21 and the network communication interface 22 are both used to transmit the control information of the external device to the main control module 5, thereby realizing remote control of the low thermal potential scanning switch, which is convenient for operating the switch in different scenarios.

[0048] Specifically, the serial communication interface 21 may be selected from but not limited to an RS232 serial communication interface 21 .

[0049] Specifically, the network in the network communication interface 22 refers to Ethernet.

[0050] In some embodiments, the main control module 5 includes a main control motherboard 51, and the main control motherboard 51 is provided with a power supply module 3, and the power supply module 3 is used to power the main control motherboard 51, the communication module 2, the display module 4, the isolation module 6, the drive module 7, the switch module 8 and the interface module 9; the main control motherboard 51 provides installation conditions for the power supply module 3; the power supply module 3 powers the main control motherboard 51, the communication module 2, the display module 4, the isolation module 6, the drive module 7, the switch module 8 and the interface module 9, so as to ensure the normal operation of the low thermal potential scanning switch.

[0051] In some embodiments, the power supply module 3 includes a power conversion module 31 and a power supply module 32. The power conversion module 31 is arranged on the main control motherboard 51, and the power supply module 32 is arranged on the chassis 1. The power supply module 32 is electrically connected to the power conversion module 31; the power conversion module 31 can convert the external current into a voltage and current suitable for the main control motherboard 51, the serial communication interface, the network communication interface 22, the display module 4, the digital isolator 61, the driver chip 71, the relay 82 and the channel terminal 94, so as to ensure the normal operation of the low thermal potential scanning switch.

[0052] Specifically, the power conversion module 31 may be, but is not limited to, an AC-DC converter.

[0053] Specifically, the power conversion module 31 converts the external current 220VAC 50Hz into 12V2A and 5V2A direct current.

[0054] In some embodiments, the power supply module 32 includes a grounding column 321, a power switch and indicator light 322, a fuse mounting seat 323 and a power socket 324. The chassis 1 is located on one side of the switch module 8 and is vertically provided with a grounding column 321, a power switch and indicator light 322, a fuse mounting seat 323 and a power socket 324 in sequence. The power socket 324 is electrically connected to the power module 3, and the grounding column 321, the power switch and indicator light 322 and the fuse mounting seat 323 are all electrically connected to the power socket 324; the power socket 324 is used to connect to an external power supply; the power switch and indicator light 322 provides the user with the option of turning on / off the power, and also serves as an indication; the fuse mounting seat 323 serves as overload / short circuit protection; the grounding column 321 serves as a safety protection.

[0055] Figure 2 Schematic diagram showing the connection between the LCD platform 41 and the chassis 1. Figure 2As shown, in some embodiments, the display module 4 includes a liquid crystal display platform 41 provided on the chassis 1, the liquid crystal display platform 41 is electrically connected to the main control module 5, and the liquid crystal display platform 41 is used to display the human-computer interaction interface; the liquid crystal display platform 41 is used to display the human-computer interaction interface, which is convenient for users to input and obtain information, thereby improving convenience; the main control module 5 and the liquid crystal display platform 41 transmit information to each other.

[0056] In some embodiments, the human-computer interaction interface displays switch control information, status query information, remote setting information, communication information and interactive buttons; the switch control information facilitates the user to control the opening and closing status of the relay 82 on each daughter card board 81; the status query information facilitates the user to view the closing and opening status of each pair of channel terminals 94 on each daughter card; the remote setting information facilitates the user to set the remote communication protocol of the low thermal potential scanning switch, that is, the remote communication protocol of the serial communication interface and the network communication interface 22; after the remote communication is successfully connected, the communication information will light up; the interactive button provides the user with selection and judgment.

[0057] Specifically, the interactive buttons include a local control button and an A-F disconnect button.

[0058] Specifically, the communication information includes WLAN and COM, wherein WLAN is a wireless local area network and COM is a bus serial port.

[0059] Specifically, the switch control information includes six sub-card information, and each sub-card information displays the status of the corresponding relay 82.

[0060] Figure 6 Schematic diagram showing the display status query information of the LCD platform 41. Figure 6 As shown, in some embodiments, the status query information includes six status bars, which correspond to six sub-cards respectively, and the six sub-cards are set as sub-card A, sub-card B, sub-card C, sub-card D, sub-card E, and sub-card F respectively. There are eight pairs of channel terminals 94 on sub-card A, which are represented by A1-A8 respectively; there are eight pairs of channel terminals 94 on sub-card B, which are represented by B1-B8 respectively; there are eight pairs of channel terminals 94 on sub-card C, which are represented by C1-C8 respectively; there are eight pairs of channel terminals 94 on sub-card D, which are represented by D1-D8 respectively; there are eight pairs of channel terminals 94 on sub-card E, which are represented by E1-E8 respectively; and there are eight pairs of channel terminals 94 on sub-card F, which are represented by F1-F8 respectively.

[0061] Specifically, A1-A8, B1-B8, C1-C8, D1-D8, E1-E8, and F1-F8 correspond to six groups of channel binding posts on chassis 1 .

[0062] Specifically, the six pairs of common terminals 93 on the chassis 1 are set as the common terminal CMA of sub-card A, the common terminal CMB of sub-card B, the common terminal CMC of sub-card C, the common terminal CMD of sub-card D, the common terminal CME of sub-card E, and the common terminal CMF of sub-card F. Each pair of common terminals 93 includes a high end and a low end, the high end is represented by H, and the low end is represented by L.

[0063] Figure 5 FIG. 4 shows a schematic diagram of the LCD platform 41 displaying switch control information. Figure 5 As shown, specifically, the switch control information includes six sub-card control information, sub-card A displays the closing and disconnecting information of the A1-A8 channel terminals 94; sub-card B displays the closing and disconnecting information of the B1-B8 channel terminals 94; sub-card C displays the closing and disconnecting information of the C1-C8 channel terminals 94; sub-card D displays the closing and disconnecting information of the D1-D8 channel terminals 94; sub-card E displays the closing and disconnecting information of the E1-E8 channel terminals 94; sub-card F displays the closing and disconnecting information of the F1-F8 channel terminals 94; users can close and disconnect according to specific needs.

[0064] Specifically, the A-F disconnect buttons can disconnect all channel terminals 94 with one click.

[0065] Specifically, the switch control information can only control the opening and closing state of one channel on the relay 82 at a time. When another channel is closed, the previous channel will be automatically opened. That is, when A2 is closed, A1 will be automatically opened.

[0066] Figure 7 FIG. 4 shows a schematic diagram of the LCD platform 41 displaying remote setting information. Figure 7 Specifically, the remote configuration information includes serial port configuration information and network port configuration information. The serial port configuration information includes bits per second, data bits, parity, stop bits, and flow control options, while the network port configuration information includes IP address, subnet mask, default gateway, and DNS server settings.

[0067] Specifically, the data of the remote setting information needs to be restarted after the setting is completed to take effect. When the remote communication connection is successful, the WLAN and COM information will be displayed.

[0068] Specifically, the local control button can restore the remote communication state to the local control state.

[0069] Specifically, the liquid crystal display platform 41 may be selected from, but not limited to, a Cortex-A7 hardware platform based on NXP's I.MX6ULL as the core, and equipped with a 10.1-inch capacitive touch screen.

[0070] In some embodiments, an indicator light module 11 is provided at a portion of the chassis 1 close to the liquid crystal display platform 41 , and the indicator light module 11 is electrically connected to the switch module 8 ; the indicator light module 11 is used to indicate the current open / close status of the switch module 8 .

[0071] Specifically, the indicator light module 11 includes a plurality of channel indicator light groups 111 , and the number of the channel indicator light groups 111 corresponds to the number of the daughter cards 81 .

[0072] Specifically, the channel indicator light group 111 is electrically connected to the relay 82 .

[0073] Specifically, there are six groups of channel indicator lights 111 , each group has eight channel indicator lights 111 , and each channel indicator light 111 corresponds to a pair of channel binding posts 94 .

[0074] In some embodiments, an indicator light module 11 is provided at a portion of the chassis 1 close to the liquid crystal display platform 41 . The indicator light module 11 is electrically connected to the relay 82 , and is used to indicate the current open / close status of the relay 82 .

[0075] Specifically, the channel indicator light 111 may be selected from but not limited to an LED indicator light.

[0076] Testing of low thermal EMF scanning switches:

[0077] Figure 8 Schematic diagram of the common terminal 93 and the nanovoltmeter circuit is shown. Figure 8 As shown, before the test, the low thermal potential scanning switch and the nanovoltmeter are preheated for 2 hours to ensure that the low thermal potential scanning switch and the nanovoltmeter are in a stable working state. Then, a single-core copper wire with a diameter of 1 mm is used to short-circuit the high and low ends of the common terminal 93 respectively. At the same time, the high and low ends of the common terminal 93 are short-circuited with the same copper wire and then connected to the input end of the nanovoltmeter. After 20 minutes, the nanovoltmeter is reset, and then the short-circuit wires at the high and low ends of the common terminal 93 are cut off. The six pairs of common terminals 93 are switched in turn for measurement, and each pair of common terminals 93 is kept for 60 seconds to record the potential with the largest absolute value. After the relay 82 is powered off for 5 minutes, the above measurement process is repeated. The measurement is repeated three times, and the maximum value of the three measurement results of each common terminal 93 is taken as the measured value of the parasitic potential of the common terminal 93. Through this test method, the performance reliability and accuracy of the low thermal potential scanning switch in actual application are ensured.

[0078] The operating principle of the low thermal EMF scanning switch is as follows:

[0079] The control signal transmitted by the main control module 5 is electrically isolated by the isolation module 6, which can effectively reduce the thermal potential, thereby meeting the requirements of high-precision measurement and calibration work and improving the accuracy and reliability of related work. Among them, after the main control motherboard 51 receives the control signal from the liquid crystal display platform 41, the serial communication interface 21 and the network communication interface 22, or after receiving the control signal from one of the control signals, the main control motherboard 51 transmits the control signal to the digital isolator 61. The digital isolator 61 isolates the control signal from the thermal potential before transmitting it to the driver chip 71. The driver chip 71 controls the relay 82 to close and open according to the control signal. When the relay 82 is closed, the channel terminal 94 corresponding to the channel terminal group is connected, and the channel indicator light 111 corresponding to the channel terminal group is lit. When the relay 82 is disconnected, the channel terminal 94 corresponding to the channel terminal group is disconnected, and the channel indicator light 111 corresponding to the channel terminal group is extinguished. The closed and open states of the relay 82 are transmitted to the liquid crystal display platform 41 through the main control motherboard 51 for the user to view.

[0080] Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A low thermal potential scanning switch, characterized in that: The invention comprises a chassis (1), wherein a main control module (5) is provided in the chassis (1), a power module (3) is provided on the main control module (5), a display module (4) is provided on the chassis (1), a switch module (8) is passed through the side of the chassis (1) away from the display module (4), an isolation module (6), a drive module (7) and an interface module (9) are provided in sequence along the vertical direction at the position of the switch module (8) in the chassis (1), a communication module (2) is provided at the position of the switch module (8) in the chassis (1), the power module (3), the communication module (2), the display module (4), the isolation module (6) and the switch module (8) are all electrically connected to the main control module (5), the isolation module (6), the drive module (7), the switch module (8) and the interface module (9) are electrically connected in sequence, the main control module (5) is used to send a control signal to the isolation module (6), and the isolation module (6) is used to electrically isolate the control signal.

2. The low thermal potential scanning switch according to claim 1, characterized in that: The isolation module (6) includes a digital isolator (61), which is provided on the switch module (8) and is electrically connected to the main control module (5).

3. The low thermal potential scanning switch according to claim 2, wherein: The switch module (8) comprises a plurality of daughter cards (81) and relays (82); the plurality of daughter cards (81) are arranged in the chassis (1); an interface module (9) penetrating the chassis (1) is provided at one end of the daughter card (81) close to the inner wall of the chassis (1); the digital isolator (61), the relay (82) and the drive module (7) are all arranged on the daughter card (81); and the digital isolator (61), the drive module (7), the relay (82) and the interface module (9) are electrically connected in sequence.

4. The low thermal potential scanning switch according to claim 3, wherein: The driving module (7) comprises a driving chip (71), the driving chip (71) is arranged on a daughter card (81), and the driving chip (71) is electrically connected to a digital isolator (61).

5. The low thermal potential scanning switch according to claim 3, wherein: The interface module (9) comprises a diode (91), a resettable fuse (92), a common terminal (93) and a channel terminal group, wherein the diode (91) and the resettable fuse (92) are both arranged on the daughter card (81), the channel terminal group is electrically connected to the relay (82), the diode (91) and the resettable fuse (92) are both electrically connected to the common terminal (93), the diode (91) and the resettable fuse (92) are both electrically connected to the channel terminal group, and the common terminal (93) and the channel terminal group are arranged in sequence vertically along the chassis (1).

6. The low thermal potential scanning switch according to claim 5, wherein: The communication module (2) includes a serial communication interface (21) and a network communication interface (22). The chassis (1) is provided with the serial communication interface (21) and the network communication interface (22) in sequence along the vertical direction at a position located at the channel terminal group. The serial communication interface (21) and the network communication interface (22) are both electrically connected to the main control module (5).

7. The low thermal potential scanning switch according to claim 1, wherein: The main control module (5) comprises a main control motherboard (51), and a power supply module (3) is provided on the main control motherboard (51). The power supply module (3) is used to supply power to the main control motherboard (51), the communication module (2), the display module (4), the isolation module (6), the drive module (7), the switch module (8), and the interface module (9).

8. The low thermal potential scanning switch according to claim 7, wherein: The power supply module (3) comprises a power conversion module (31) and a power supply module (32); the power conversion module (31) is arranged on the main control motherboard (51); the power supply module (32) is arranged on the chassis (1); and the power supply module (32) is electrically connected to the power conversion module (31).

9. The low thermal potential scanning switch according to claim 1, wherein: The display module (4) comprises a liquid crystal display platform (41) provided on the chassis (1); the liquid crystal display platform (41) is electrically connected to the main control module (5); and the liquid crystal display platform (41) is used to display a human-computer interaction interface.

10. The low thermal potential scanning switch according to claim 1, wherein: An indicator light module (11) is provided at a position of the chassis (1) close to the liquid crystal display platform (41), and the indicator light module (11) is electrically connected to the switch module (8).

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