A protection circuit, a terminal block, a low temperature sensor system

Abstract

This utility model discloses a protection circuit, a terminal block, and a cryogenic sensor system. The protection circuit of this application is characterized by comprising a first surge protection module and a second surge protection module; wherein the first surge protection module comprises a first junction field-effect transistor and a first TVS diode connected in series; the second surge protection module comprises a second junction field-effect transistor and a second TVS diode connected in series; the first surge protection module and the second surge protection module are connected in reverse parallel on the same signal line to suppress forward and reverse overshoot voltages on the signal line. The terminal block of this application includes the above-mentioned protection circuit; the cryogenic sensor system of this application includes an input module, multiple cryogenic sensors, and the terminal block. The protection circuit of this application not only reduces leakage current during normal circuit operation but also effectively protects the internal circuitry when the circuit malfunctions.

Description

Technical Field

[0001] This utility model relates to the field of terminal block technology, and in particular to a protection circuit, a terminal block, and a low-temperature sensor system. Background Technology

[0002] In existing cryogenic sensor systems, the input module typically employs a constant current output mode, operating by transmitting a voltage signal after sampling by an external cryogenic sensor. However, when the signal line of the cryogenic sensor extends for hundreds of meters, it is susceptible to interference from ambient noise, especially in strong magnetic field environments, where extremely high surge voltages can be induced on the signal line.

[0003] The aforementioned problems are particularly pronounced under abnormal operating conditions of the superconducting magnet (such as the moment of quench loss): the extremely high reverse voltage spike generated at the moment of quench loss releases a strong magnetic field, which in turn induces a high voltage on the signal line and forms a strong electromagnetic field in space. At this time, the high voltage pulse generated by the electromagnetic field will be introduced into the input module of the cryogenic sensor system through the signal line, ultimately causing irreversible damage to the input module. Utility Model Content

[0004] To address the technical problems existing in the prior art, the purpose of this utility model is to provide a protection circuit, wiring terminal, and low-temperature sensor system.

[0005] The objective of this utility model is achieved through the following technical solution:

[0006] A protection circuit, characterized in that it includes a first surge protection module and a second surge protection module; wherein,

[0007] The first surge protection module includes a first junction field-effect transistor and a first TVS diode connected in series;

[0008] The second surge protection module includes a second junction field-effect transistor and a second TVS diode connected in series;

[0009] The first surge protection module and the second surge protection module are connected in parallel in opposite directions on the same signal line to suppress forward and reverse overshoot voltages on the signal line.

[0010] Furthermore, the gate of the first junction field-effect transistor is connected to a signal line, the drain and source are both connected to the anode of the first TVS diode, and the cathode of the first TVS diode is grounded; the drain and source of the second junction field-effect transistor are both connected to a signal line, the gate is connected to the cathode of the second TVS diode, and the anode of the second TVS diode is grounded.

[0011] Furthermore, a resistor is connected in series on the signal line to reduce signal reflections in the signal line.

[0012] Furthermore, the leakage current of both the first junction field-effect transistor and the second junction field-effect transistor is less than 1nA, and the leakage current of both the first TVS diode and the second TVS diode is less than 10nA.

[0013] A terminal block, characterized in that it includes any of the protection circuits described above.

[0014] A terminal block, characterized in that it comprises an insulating body, a first surge protection module, and a second surge protection module; wherein,

[0015] The insulating body includes a pin component and a socket component, and the pin component and the socket component are connected by a plurality of wires;

[0016] The first surge protection module includes a first junction field-effect transistor and a first TVS diode connected in series;

[0017] The second surge protection module includes a second junction field-effect transistor and a second TVS diode connected in series;

[0018] Each of the aforementioned conductors is connected in reverse parallel with a first surge protection module and a second surge protection module to suppress forward and reverse overshoot voltages on the conductors.

[0019] Furthermore, the gate of the first junction field-effect transistor is connected to a signal line, the drain and source are both connected to the anode of the first TVS diode, and the cathode of the first TVS diode is grounded; the drain and source of the second junction field-effect transistor are both connected to a signal line, the gate is connected to the cathode of the second TVS diode, and the anode of the second TVS diode is grounded.

[0020] Furthermore, a resistor is connected in series with each of the wires to reduce signal reflections in the wires.

[0021] Furthermore, the leakage current of both the first junction field-effect transistor and the second junction field-effect transistor is less than 1nA, and the leakage current of both the first TVS diode and the second TVS diode is less than 10nA.

[0022] A low-temperature sensor system, characterized in that it includes an input module, a plurality of low-temperature sensors, and any of the aforementioned wiring terminals;

[0023] The input module is connected to the terminal block and is used to send a current signal to the low-temperature sensor via the terminal block, and to receive a voltage signal returned via the terminal block.

[0024] Multiple low-temperature sensors are respectively connected to the wiring terminals to collect signals from the temperature probes and convert them into voltage signals, which are then sent to the input module via the wiring terminals.

[0025] In a first aspect, this utility model provides a protection circuit, including:

[0026] The first surge protection module includes a first junction field-effect transistor and a first TVS diode connected in series.

[0027] The second surge protection module includes a second junction field-effect transistor and a second TVS diode connected in series.

[0028] The protection circuit is configured to connect the first surge protection module and the second surge protection module in reverse parallel on the same signal line.

[0029] In conjunction with the first aspect, this utility model also provides a first specific embodiment of the first aspect, wherein the gate of the first junction field-effect transistor is connected to a signal line, the drain and source of the first junction field-effect transistor are both connected to the anode of the first TVS diode, and the cathode of the first TVS diode is grounded.

[0030] In conjunction with the first aspect, this utility model also provides a second specific embodiment of the first aspect. Specifically, the drain and source of the second junction field-effect transistor are both connected to the signal line, the gate of the second junction field-effect transistor is connected to the cathode of the second TVS diode, and the anode of the second TVS diode is grounded.

[0031] In conjunction with the first aspect, this utility model also provides a third specific embodiment of the first aspect, specifically, the protection circuit further includes:

[0032] A resistor, which is connected in series with the signal line.

[0033] Secondly, this utility model also provides a terminal block, which is provided with the protection circuit described in the first aspect and the first to third specific embodiments of the first aspect.

[0034] Thirdly, this utility model provides a wiring terminal, the wiring terminal comprising:

[0035] An insulating body having a pin component and a socket component, the pin component and the socket component being connected by multiple wires;

[0036] Multiple first surge protection modules, each first surge protection module comprising a first junction field-effect transistor and a first TVS diode connected in series;

[0037] Multiple second surge protection modules, each of which includes a second junction field-effect transistor and a second TVS diode connected in series;

[0038] In this configuration, one of the first surge protection modules and one of the second surge protection modules are connected in parallel in opposite directions on the same conductor.

[0039] In conjunction with the second aspect, this utility model also provides a first specific embodiment of the second aspect. Specifically, the gate of the first junction field-effect transistor is connected to the wire, the drain and source of the first junction field-effect transistor are both connected to the anode of the first TVS diode, and the cathode of the first TVS diode is grounded.

[0040] In conjunction with the second aspect, this utility model also provides a second specific embodiment of the second aspect, wherein the drain and source of the second junction field-effect transistor are both connected to the wire, the gate of the second junction field-effect transistor is connected to the cathode of the second TVS diode, and the anode of the second TVS diode is grounded.

[0041] In conjunction with the second aspect, this utility model also provides a third specific embodiment of the second aspect, wherein the wiring terminal includes:

[0042] Multiple resistors, one of which is connected in series with one of the wires.

[0043] Fourthly, this utility model also provides a low-temperature sensor system, which includes an input module, multiple low-temperature sensors, and a terminal block as described in the first to third specific embodiments of the second or third aspects.

[0044] The input module is connected to the terminal block and is used to send a current signal to the low-temperature sensor via the terminal block, and to receive a voltage signal returned via the terminal block.

[0045] Multiple low-temperature sensors are connected to the terminal block to collect signals from the temperature probe and convert them into voltage signals, which are then sent to the input module via the terminal block.

[0046] Compared with the prior art, the present invention has at least the following beneficial effects:

[0047] 1. This utility model provides a protection circuit, which includes a first surge protection module and a second surge protection module. The first surge protection module includes a first junction field-effect transistor and a first TVS diode connected in series; the second surge protection module includes a second junction field-effect transistor and a second TVS diode connected in series. The protection circuit is configured to connect the first surge protection module and the second surge protection module in reverse parallel on the same signal line.

[0048] The protection circuit employs a design using a low-leakage-current junction field-effect transistor (JFET) connected in series with a similarly low-leakage-current TVS diode. The low leakage current of the JFET is utilized to block the impact of leakage current on signal accuracy. The TVS diode also functions in the event of voltage spikes. When the voltage on the signal line exceeds the breakdown voltage of the TVS diode, both the JFET and the TVS diode conduct simultaneously, clamping the voltage on the conductor to a lower level. This design not only reduces leakage current during normal circuit operation but also effectively protects the internal circuitry in case of malfunctions.

[0049] 2. The wiring terminals and low-temperature sensor system of this utility model adopt the same or similar technologies as the terminal components mentioned above, and therefore have the same technical effects. Attached Figure Description

[0050] Figure 1 This is a circuit topology diagram of the protection circuit of this utility model.

[0051] Figure 2 This is a schematic diagram of the structure of the wiring terminal of this utility model.

[0052] Figure 3 This is a simplified connection diagram of the position sensor system of this utility model.

[0053] Reference numerals: 100-terminal block, 110-pin assembly, 120-sleeve assembly; 200-protection circuit, 300-surge protection module, 400-signal line, 500-resistor, 600-input module, 700-low temperature sensor. Detailed Implementation

[0054] To facilitate understanding of this utility model, the technical solutions and advantages of the utility model will be further described in detail below with reference to the accompanying drawings and embodiments. Any mechanisms or methods not elaborated in this utility model can be referred to in the prior art. The specific structure and features of this utility model are illustrated below by way of example and should not constitute any limitation on this utility model. Furthermore, any technical feature mentioned below (including implicit or disclosed features), as well as any technical feature directly shown or implied in the figures, can be arbitrarily combined or deleted among these technical features to form more other embodiments that may not be directly or indirectly mentioned in this utility model. The accompanying drawings show preferred embodiments of this utility model. However, this utility model can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of the disclosure of this utility model.

[0055] Traditional surge and overshoot protection circuits typically use ordinary TVS diodes (transient voltage suppressor diodes), but this design has significant drawbacks: TVS diodes generate substantial leakage current in the circuit, which severely impacts the accuracy of precision signals (such as signals processed by cryogenic sensor input modules). Furthermore, leakage current increases the power consumption of the TVS diode, and its performance deteriorates or even fails under high temperatures or prolonged operation, thus reducing protection effectiveness and affecting signal stability.

[0056] Therefore, many high-precision cryogenic sensor input modules do not employ TVS diode protection to avoid leakage current interference, but this makes them vulnerable to surges and high-voltage pulses. Although some low-leakage-current TVS diodes (leakage current in the tens of nanoamps range) can partially alleviate the problem, their impact is still significant for ultra-high-precision signals. This contradiction reduces the reliability of the equipment in environments with strong interference, necessitating a more optimized protection solution.

[0057] Therefore, this utility model provides a protection circuit 200, which aims to solve the problems existing in traditional surge protection and overshoot protection circuits, especially in the application of high-precision cryogenic sensor input modules. This protection circuit design, by combining low-leakage-current junction field-effect transistors and TVS diodes, provides an effective solution to address the problems existing in traditional surge protection and overshoot protection circuits, especially in high-precision applications.

[0058] like Figure 1 As shown, the protection circuit includes a first surge protection module and a second surge protection module. The first surge protection module includes a first junction field-effect transistor and a first TVS diode connected in series; the second surge protection module includes a second junction field-effect transistor and a second TVS diode connected in series. The protection circuit is configured to connect the first and second surge protection modules in reverse parallel on the same signal line 400.

[0059] The protection circuit 200 is suitable for applications requiring high-precision signal transmission and processing, such as signal transmission between the input module and the cryogenic sensor in a cryogenic sensor system, and can effectively prevent leakage current from affecting signal accuracy.

[0060] Specifically, the protection circuit 200 employs a design using a low-leakage-current junction field-effect transistor (JFET) connected in series with a similarly low-leakage-current TVS diode. The low leakage current of the JFET is utilized to block the impact of leakage current on signal accuracy. The JFET's leakage current is less than 1 nA, typically in the picoampere range, while the TVS diode's leakage current is less than 10 nA. The TVS diode also functions in the event of voltage spikes. When the voltage on the signal line exceeds the TVS diode's breakdown voltage, both the JFET and TVS diode conduct simultaneously, clamping the voltage on the conductor to a lower level. This design not only reduces leakage current during normal circuit operation but also effectively protects the internal circuitry in case of malfunctions.

[0061] In a specific implementation, the gate of the first junction field-effect transistor is connected to the signal line, the drain and source of the first junction field-effect transistor are both connected to the anode of the first TVS diode, and the cathode of the first TVS diode is grounded.

[0062] In practice, the drain and source of the second junction field-effect transistor are both connected to the signal line, the gate of the second junction field-effect transistor is connected to the cathode of the second TVS diode, and the anode of the second TVS diode is grounded.

[0063] In one specific implementation, the leakage current of the junction field-effect transistor (JFET) is 1 nA. This low leakage current characteristic of the JFET is utilized to block the influence of leakage current on signal accuracy.

[0064] In a preferred embodiment, the protection circuit 200 further includes a resistor 500 connected in series with the signal line. This resistor effectively reduces signal reflection problems in the signal line.

[0065] By equipping the same signal line with a first surge protection module and a second surge protection module, and employing an anti-parallel design, the two surge protection modules 300 connected in reverse parallel can suppress forward and reverse overshoot voltages respectively. This allows the design to simultaneously protect the signal line from voltage spikes in both directions (positive and negative bipolar), making it suitable for applications involving both bipolar and unipolar signal transmission.

[0066] like Figure 2 As shown, this utility model also provides a terminal block, in which the aforementioned protection circuit 200 is connected to the wires of the terminal block, and the wires serve as signal lines.

[0067] In one specific implementation, the terminal block 100 includes an insulating body, a plurality of first surge protection modules, and a plurality of second surge protection modules. The insulating body has a pin component 110 and a socket component 120, which are connected by a plurality of wires. Each first surge protection module includes a first junction field-effect transistor (JFET) and a first TVS diode connected in series. Each second surge protection module includes a second JFET and a second TVS diode connected in series, wherein one first surge protection module and one second surge protection module are connected in parallel in reverse on the same wire.

[0068] In practical implementation, the insulating body is the core structure of the terminal block, used to fix and protect the internal wires and surge protection module. It provides mechanical support and electrical insulation, ensuring the safety and reliability of the terminal block during use. The insulating body is typically made of high-strength insulating materials such as polycarbonate or polyimide. It includes pin components and socket components, which are connected by multiple wires to form a complete electrical connection system.

[0069] In practical implementation, the pin component 110 is the anode portion of the terminal block, used to insert into the socket component to form an electrical connection. The pin component 110 is typically made of a conductive material, such as a copper alloy, to ensure good conductivity. The socket component 120 is the cathode portion of the terminal block, used to receive the pin component and form a stable electrical connection. The socket component 120 is also made of a conductive material and is typically designed with resilient contact points to ensure tight contact after the pin component is inserted.

[0070] Specifically, the pin and socket components are connected by multiple wires used to transmit current and signals. The number and arrangement of the wires are designed according to actual needs to meet different electrical connection requirements.

[0071] In one specific embodiment, the gate of the first junction field-effect transistor is connected to a wire, the drain and source of the first junction field-effect transistor are both connected to the anode of the first TVS diode, and the cathode of the first TVS diode is grounded.

[0072] In one specific embodiment, the drain and source of the second junction field-effect transistor are both connected to wires, the gate of the second junction field-effect transistor is connected to the cathode of the second TVS diode, and the anode of the second TVS diode is grounded.

[0073] In one specific implementation, the terminal block includes multiple resistors 500, with each resistor 500 connected in series with a conductor 400. Resistors effectively reduce signal reflections in the signal line.

[0074] like Figure 3As shown, this utility model also provides a low-temperature sensor system, which includes an input module 600, a plurality of low-temperature sensors 700 and the aforementioned terminal block 100; the input module 600 is connected to the pin component 110 of the terminal block 100, and the plurality of low-temperature sensors 700 are connected to the socket component 120 of the terminal block 100.

[0075] The cryogenic sensor system achieves high accuracy, high reliability, and robust overshoot voltage protection through its protective terminal blocks, a circuit design employing a low-leakage-current junction field-effect transistor (JFET) and a TVS diode connected in series, and reverse parallel protection. This design improves the accuracy and integrity of signal transmission. These advantages enable the cryogenic sensor system to adapt to various complex cryogenic environments, meet the needs of modern cryogenic monitoring, and improve the efficiency and convenience of monitoring work.

[0076] The above embodiments are merely preferred embodiments of the present utility model and should not be construed as limiting the scope of protection of the present utility model. For those skilled in the art, it will be understood that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present utility model. The scope of the present utility model is defined by the appended claims and their equivalents.

Claims

1. A protection circuit, characterized in that, Includes a first surge protection module and a second surge protection module; among which, The first surge protection module includes a first junction field-effect transistor and a first TVS diode connected in series; The second surge protection module includes a second junction field-effect transistor and a second TVS diode connected in series; The first surge protection module and the second surge protection module are connected in parallel in opposite directions on the same signal line to suppress forward and reverse overshoot voltages on the signal line.

2. The protection circuit according to claim 1, characterized in that, The gate of the first junction field-effect transistor is connected to a signal line, and both its drain and source are connected to the anode of the first TVS diode, while the cathode of the first TVS diode is grounded. The drain and source of the second junction field-effect transistor are both connected to a signal line, and its gate is connected to the cathode of the second TVS diode, while the anode of the second TVS diode is grounded.

3. The protection circuit according to claim 1, characterized in that, A resistor is connected in series in the signal line to reduce signal reflections in the signal line.

4. The protection circuit according to claim 1, 2, or 3, characterized in that, The leakage current of the first junction field-effect transistor and the second junction field-effect transistor is less than 1nA, and the leakage current of the first TVS diode and the second TVS diode is less than 10nA.

5. A terminal block, characterized in that, Includes the protection circuit described in any one of claims 1 to 4.

6. A terminal block, characterized in that, It includes an insulating body, a first surge protection module, and a second surge protection module; wherein, the insulating body includes a pin component and a socket component, and the pin component and the socket component are connected by several wires; The first surge protection module includes a first junction field-effect transistor and a first TVS diode connected in series; The second surge protection module includes a second junction field-effect transistor and a second TVS diode connected in series; Each of the aforementioned conductors is connected in reverse parallel with a first surge protection module and a second surge protection module to suppress forward and reverse overshoot voltages on the conductors.

7. The terminal block according to claim 6, characterized in that, The gate of the first junction field-effect transistor is connected to a signal line, and both its drain and source are connected to the anode of the first TVS diode, while the cathode of the first TVS diode is grounded. The drain and source of the second junction field-effect transistor are both connected to a signal line, and its gate is connected to the cathode of the second TVS diode, while the anode of the second TVS diode is grounded.

8. The terminal block according to claim 6 or 7, characterized in that, A resistor is connected in series with each of the wires to reduce signal reflections in the wires.

9. The terminal block according to claim 6 or 7, characterized in that, The leakage current of the first junction field-effect transistor and the second junction field-effect transistor is less than 1nA, and the leakage current of the first TVS diode and the second TVS diode is less than 10nA.

10. A low-temperature sensor system, characterized in that, Includes an input module, multiple low-temperature sensors, and the terminal block as described in claim 5 or any one of claims 6 to 9; The input module is connected to the terminal block and is used to send a current signal to the low-temperature sensor via the terminal block, and to receive a voltage signal returned via the terminal block. Multiple low-temperature sensors are respectively connected to the wiring terminals to collect signals from the temperature probes and convert them into voltage signals, which are then sent to the input module via the wiring terminals.

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