Signal transmitting device

Abstract

The utility model provides a signal transmitting device, which comprises a signal conversion module and a power supply conversion module, and is characterized in that the signal conversion module stably accesses a voltage signal needing to be transmitted through a voltage following circuit and a signal amplification circuit, amplifies the voltage signal and then outputs the amplified voltage signal; the power conversion module comprises a DC-DC step-down circuit, an input end of the DC-DC step-down circuit is connected to a power port of the signal receiving end, an output end of the DC-DC step-down circuit is connected to a power port of the signal transmitting end, the DC-DC step-down circuit performs equal-power transmission, and an output current can be greater than an input current. Therefore, the magnitude of current for supplying power to the sensor at the transmitting end can be improved, and convenience is provided for performance release of the sensor. The signal transmitting device provided by the utility model can improve the magnitude of the current for supplying power to the sensor at the transmitting end, reduce the limitation of the current limitation of the transmission line on the performance of the sensor, improve the performance of the sensor, reduce the requirement on a special chip, and reduce the cost.

Description

Technical Field

[0001] This utility model relates to the field of electrical signal transmission technology, and in particular to a signal transmission device. Background Technology

[0002] In signal transmission, voltage signals are easily affected by external interference. Therefore, current signals are often used for transmission. Current signals are not easily affected by interference, and the internal resistance of the current source is infinite. The resistance of the wire in series in the circuit does not affect the accuracy. It can transmit hundreds of meters on ordinary twisted pair cables.

[0003] Considering safety, practicality, power consumption, and cost, international standards stipulate that the current magnitude in current signal transmission is 4mA-20mA. In existing technologies, for communication between the sensor and the main controller, the dedicated chip for signal transmission typically uses a low-dropout regulator (LDO) to draw power from the main controller to provide operating power to the sensor. When the LDO is operating, the input current must be greater than the output current. However, when the LDO draws power from the main controller, the main controller's output current is generally limited to 4mA, resulting in the sensor receiving less than 4mA of current. This leads to insufficient power supply to the sensor, limiting its performance. Utility Model Content

[0004] Therefore, the purpose of this utility model is to provide a signal transmission device to solve the problem that the dedicated chip for signal transmission in the prior art has insufficient power supply capability to the sensor, which limits the performance of the sensor.

[0005] This utility model provides a signal transmission device, comprising: a signal conversion module and a power conversion module, wherein,

[0006] The signal conversion module includes a voltage follower circuit and a signal amplification circuit. The input terminal of the voltage follower circuit is connected to the transmission signal input terminal of the signal conversion module, the output terminal of the voltage follower circuit is connected to the input terminal of the signal amplification circuit, and the output terminal of the signal amplification circuit is connected to the output terminal of the signal conversion module.

[0007] The power conversion module includes a DC-to-DC buck converter circuit. The input terminal of the DC-to-DC buck converter circuit is connected to the power port of the signal receiver, and the output terminal of the DC-to-DC buck converter circuit is connected to the power port of the signal transmitter. The DC-to-DC buck converter circuit is a Buck topology.

[0008] Optionally, the DC-to-DC step-down circuit includes an LV2842XLVDDCR power supply chip.

[0009] Optionally, a seventh capacitor is connected between the output terminal and the feedback terminal of the DC-to-DC buck converter.

[0010] Optionally, the output terminal of the DC-to-DC step-down circuit is further connected to a filter circuit, which includes an eighth capacitor, a ninth capacitor, and a ninth resistor. The first terminals of the eighth capacitor and the ninth capacitor are connected to the output terminal of the DC-to-DC step-down circuit, the second terminals of the eighth capacitor and the ninth capacitor are grounded, and the ninth resistor is connected between the second terminals of the eighth capacitor and the ninth capacitor.

[0011] Optionally, a fifth capacitor and a sixth capacitor are connected in series between the input terminal of the DC-to-DC step-down circuit and ground.

[0012] Optionally, the signal amplification circuit includes a first operational amplifier and a transistor, wherein,

[0013] The non-inverting input of the first operational amplifier is connected to the output of the voltage follower circuit, the inverting input of the first operational amplifier is grounded, the non-inverting input of the first operational amplifier is also connected to the current signal output of the signal amplification circuit through a fourth resistor and a sixth resistor connected in series, the positive power supply terminal of the first operational amplifier is connected to the second power supply input terminal of the signal amplification circuit, and the negative power supply terminal of the first operational amplifier is grounded.

[0014] The base of the transistor is connected to the output terminal of the first operational amplifier, the collector of the transistor is connected to the first power input terminal of the signal amplification circuit, and the emitter of the transistor is connected to the current signal output terminal of the signal amplification circuit through a fifth resistor and a seventh resistor connected in series.

[0015] The intermediate node between the fifth resistor and the seventh resistor is grounded;

[0016] The first power input terminal of the signal amplification circuit is connected to the input terminal of the DC-to-DC step-down circuit, and the second power input terminal of the signal amplification circuit is connected to the output terminal of the DC-to-DC step-down circuit.

[0017] Optionally, a second capacitor and a third capacitor are connected in series between the first power input terminal and the current signal output terminal of the signal amplification circuit.

[0018] Optionally, a first resistor is connected in series between the positive power supply terminal of the first operational amplifier and the second power supply input terminal of the signal amplification circuit, and the positive power supply terminal of the first operational amplifier is also grounded through a first capacitor.

[0019] Optionally, the signal transmitter includes a twisted-pair interface, and the current signal output terminal of the signal amplifier circuit is connected to two signal ports of the twisted-pair interface through two first diodes, and the two signal ports of the twisted-pair interface are also connected to the first power input terminal of the signal amplifier circuit through two second diodes.

[0020] Optionally, a second resistor is connected in series on the input path of the first power input terminal of the signal amplification circuit.

[0021] The signal transmission device provided by this utility model includes a signal conversion module and a power conversion module. The signal conversion module includes a voltage follower circuit and a signal amplification circuit. The input terminal of the voltage follower circuit is connected to the signal input terminal of the signal conversion module, and the output terminal of the voltage follower circuit is connected to the input terminal of the signal amplification circuit. The output terminal of the signal amplification circuit is connected to the output terminal of the signal conversion module, stably transmitting the voltage signal to be transmitted to the signal amplification circuit. The signal amplification circuit then converts the voltage signal into a current signal, amplifies it, and outputs it. The power conversion module includes a DC-DC step-down circuit. The input terminal of the DC-DC step-down circuit is connected to the power port of the signal receiver, and the output terminal of the DC-DC step-down circuit is connected to the power port of the signal transmitter. The DC-DC step-down circuit provides equal power transmission, and the output current can be greater than the input current, thereby increasing the current supplied to the sensor at the transmitter and facilitating the release of sensor performance. The signal transmission device provided by this utility model can increase the current supplied to the sensor at the transmitter, reduce the current limitation of the transmission line on sensor performance, improve sensor performance, and reduce the need for dedicated chips, thus reducing costs. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the main module structure of the signal transmission device in this embodiment of the utility model;

[0023] Figure 2 This is a schematic diagram of the circuit principle of the power conversion module of the signal transmission device in this embodiment of the present invention;

[0024] Figure 3 This is a schematic diagram of the circuit principle of the signal conversion module of the signal transmission device in an embodiment of this utility model.

[0025] The following detailed description, in conjunction with the accompanying drawings, will further illustrate this utility model. Detailed Implementation

[0026] To facilitate understanding of this utility model, a more complete description will be given below with reference to the accompanying drawings. Several embodiments of this utility model are shown in the drawings. 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 so that the disclosure of this utility model will be more thorough and complete.

[0027] It should be noted that when a component is said to be "fixed to" another component, it can be directly on the other component or there may be an intervening component. When a component is said to be "connected to" another component, it can be directly connected to the other component or there may be an intervening component. The terms "vertical," "horizontal," "left," "right," and similar expressions used in this document are for illustrative purposes only.

[0028] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0029] To address the problem of insufficient power supply to sensors by dedicated signal transmission chips in existing technologies, which limits sensor performance, this invention provides a signal transmission device, including a signal conversion module and a power conversion module. The signal conversion module uses a voltage follower circuit and a signal amplification circuit to stably input and amplify the voltage signal to be transmitted before outputting it. The power conversion module includes a DC-DC step-down circuit. The input of the DC-DC step-down circuit is connected to the power port of the signal receiver, and the output is connected to the power port of the signal transmitter. The DC-DC step-down circuit provides equal power transmission, and its output current can be greater than its input current, thereby increasing the current supplied to the sensor at the transmitter, facilitating the release of sensor performance, and reducing the need for dedicated signal transmission chips, thus lowering costs.

[0030] Please see Figures 1 to 3 The diagram shows the structural schematic of the signal transmission device in this embodiment of the present invention. It mainly includes a signal conversion module 10 and a power conversion module 20. The power conversion module 20 draws power from the signal receiving end to provide power to the signal transmitting end and the signal conversion module 10. The signal conversion module 10 is used to convert the input voltage signal into a current signal and output it. The signal receiving end is, for example, a microcontroller or an industrial control computer. The signal transmitting end is mainly an electronic device with a small output signal, such as a sensor. The microcontroller powers the sensor and collects the sensor's sensing signal to obtain the collected data information.

[0031] As a specific example, in this embodiment, the signal receiving end can provide 24V DC power supply, and the operating voltage of the signal transmitting end is 3.3V. The actual voltage specifications are related to the specific scenario, and this application does not make any special limitations on them.

[0032] The signal conversion module 10 includes a voltage follower circuit 11 and a signal amplification circuit 12. The input terminal of the voltage follower circuit 11 is connected to the transmission signal input terminal of the signal conversion module 10 to receive the sensing signal Ur. The output terminal of the voltage follower circuit 11 is connected to the input terminal of the signal amplification circuit 12 to stably transmit the sensing signal Ur to the signal amplification circuit 12. The output terminal of the signal amplification circuit 12 is connected to the output terminal of the signal conversion module 10 to convert the sensing signal Ur into a current signal output.

[0033] The power conversion module 20 includes a DC-to-DC step-down circuit 21. The input terminal of the DC-to-DC step-down circuit 21 is connected to the power port of the signal receiver, and the output terminal of the DC-to-DC step-down circuit 21 is connected to the power port of the signal transmitter, converting the 24V power supply of the signal receiver to the 3.3V operating power supply of the signal transmitter. Figure 2 As shown, the DC-to-DC step-down circuit 21 is a Buck topology and can convert power at the same level.

[0034] Specifically, the power supply chip U3 of the DC-to-DC step-down circuit 21 includes an LV2842XLVDDCR type power supply chip, which has a conversion efficiency of up to 90% in the operating range of 4mA to 20mA. When the signal receiving end is provided with 24V and 4mA power supply, the output 3.3V DC power supply current can reach 26mA, which can effectively ensure the current driving capability of the transmitting end sensor, make the sensing signal less likely to be covered, improve the anti-interference capability of the transmitting end sensor, and improve the working reliability of the transmitting end sensor.

[0035] To improve the accuracy of the power supply voltage and ensure the accuracy of the sensor, in this embodiment, a seventh capacitor C7 is connected between the output terminal of the DC-to-DC step-down circuit 21 and the feedback terminal (FB pin of the power chip U3). This can improve the output voltage stability of the Buck topology and ensure the voltage accuracy of the 3.3V power supply.

[0036] To further ensure the output voltage stability of the power conversion module 20 with Buck topology, in this embodiment, a filter circuit is also connected to the output terminal of the DC-to-DC buck circuit 21. The filter circuit includes an eighth capacitor C8, a ninth capacitor C9, and a ninth resistor R9. The first terminals of the eighth capacitor C8 and the ninth capacitor C9 are connected to the output terminal of the DC-to-DC buck circuit 21, and the second terminals of the eighth capacitor C8 and the ninth capacitor C9 are grounded. The ninth resistor R9 is connected between the second terminals of the eighth capacitor C8 and the ninth capacitor C9 to improve the stability of the 3.3V power supply.

[0037] The DC-to-DC step-down circuit 21 also has a fifth capacitor C5 and a sixth capacitor C6 connected in series between the input terminal and ground. This can filter and regulate the input power supply, improve the stability of the 24V input power supply, and thus improve the stability of the output power supply.

[0038] By implementing a filtering and voltage regulation design for the Buck topology power conversion module 20, the stability of its output voltage can be effectively guaranteed, achieving a voltage regulation effect comparable to a low dropout linear regulator, thereby reducing power supply costs.

[0039] The voltage follower circuit 11 mainly includes a third resistor R3 and a second operational amplifier U2. The third resistor R3 is connected in series in the output path of the second operational amplifier U2. The output terminal of the second operational amplifier U2 is connected to the inverting input terminal, and the non-inverting input terminal is connected to the sensing signal Ur. The sensing signal Ur is stably transmitted to the signal amplification circuit 12, and the first current I1 flowing through the third resistor R3 is Ur / R3.

[0040] The signal amplification circuit 12 includes a first operational amplifier U1 and a transistor Q1. The non-inverting input of the first operational amplifier U1 is connected to the output of the voltage follower circuit 11, and the inverting input of the first operational amplifier U1 is grounded. The non-inverting input of the first operational amplifier U1 is also connected to the current signal output of the signal amplification circuit 12 through a fourth resistor R4 and a sixth resistor R6 connected in series. The positive power supply terminal of the first operational amplifier U1 is connected to the second power supply input terminal of the signal amplification circuit 12, and the negative power supply terminal of the first operational amplifier U1 is grounded. The sensing signal Ur outputs a first current through the fourth resistor R4 and the sixth resistor R6, which drives the first operational amplifier U1 to control the transistor Q1 to operate in amplification mode.

[0041] The base of transistor Q1 is connected to the output terminal of the first operational amplifier U1, the collector of transistor Q1 is connected to the first power input terminal of the signal amplifier circuit 12, and the emitter of transistor Q1 is connected to the current signal output terminal of the signal amplifier circuit 12 through the fifth resistor R5 and the seventh resistor R7 connected in series. The intermediate node of the fifth resistor R5 and the seventh resistor R7 is grounded.

[0042] The output current I0 of the signal amplification circuit 12 is I0 = (Ur / R3) + (Ur(R4+R6) / (R3+R7)). When the sensing signal Ur is between 0.4V and 2V, R3 = 10KΩ. To achieve 100x amplification, the resistance values ​​of the fourth resistor R4, the sixth resistor R6, and the seventh resistor R7 can be selected as follows: R4 = 1.8KΩ, R6 = 180Ω, and R7 = 20Ω. By selecting resistors with a precision of 0.1%, the signal amplification accuracy can be guaranteed. The specific resistance values ​​and precision of each resistor can be selected according to the specific amplification and precision requirements, and this application does not impose any special limitations on this.

[0043] The first power input terminal of the signal amplifier circuit 12 is connected to the input terminal of the DC-to-DC step-down circuit 21 to receive a 24V stable voltage, and the second power input terminal of the signal amplifier circuit 12 is connected to the output terminal of the DC-to-DC step-down circuit 21 to receive a 3.3V stable voltage.

[0044] To improve the stability of the output signal of the signal transmitter module 20, in this embodiment, a second capacitor C2 and a third capacitor C3 are connected in series between the first power input terminal and the current signal output terminal of the signal amplifier circuit 12, which can improve the stability of the input and output voltage and current.

[0045] A first resistor R1 is connected in series between the positive power supply terminal of the first operational amplifier U1 and the second power supply input terminal of the signal amplification circuit. The positive power supply terminal of the first operational amplifier U1 is also grounded through the first capacitor C1, forming an RC filter circuit, which can improve the working stability of the operational amplifier U1, thereby ensuring the amplification accuracy and the operational reliability of the signal amplification circuit 12.

[0046] To facilitate wiring, in this embodiment, the signal transmitter includes a twisted-pair interface. The current signal output terminal of the signal amplifier circuit 12 is connected to the two signal ports of the twisted-pair interface through two first diodes. The two signal ports of the twisted-pair interface are also connected to the first power input terminal of the signal amplifier circuit 12 through two second diodes, which can automatically allocate input and output.

[0047] A second resistor R2 is connected in series on the input path of the first power input terminal of the signal amplifier circuit 12, which can further improve the filtering and voltage regulation effect, and limit the input current, reducing the impact of overcurrent interference on the system.

[0048] The signal transmission device provided by this utility model includes a signal conversion module and a power conversion module. The signal conversion module uses a voltage follower circuit and a signal amplification circuit to stably input the voltage signal to be transmitted and then amplify and output it. The power conversion module includes a DC-DC step-down circuit. The input terminal of the DC-DC step-down circuit is connected to the power port of the signal receiving end, and the output terminal of the DC-DC step-down circuit is connected to the power port of the signal transmitting end. The DC-DC step-down circuit provides equal power transmission, and the output current can be greater than the input current, thereby increasing the current supplied to the sensor at the transmitting end, facilitating the release of sensor performance, and reducing the need for dedicated signal transmission chips, thus reducing costs.

[0049] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0050] The embodiments described above are merely illustrative of several specific implementations of this utility model, and while the descriptions are detailed, they should not be construed as limiting the scope of this utility model patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this utility model, and these all fall within the protection scope of this utility model. Therefore, the protection scope of this utility model patent should be determined by the appended claims.

Claims

1. A signal transmitter, characterized in that, The signal conversion module and the power conversion module comprise: The signal conversion module comprises a voltage follower circuit and a signal amplification circuit, the input end of the voltage follower circuit is connected to the signal conversion module, the output end of the voltage follower circuit is connected to the input end of the signal amplification circuit, and the output end of the signal amplification circuit is connected to the output end of the signal conversion module. The power conversion module comprises a DC-DC step-down circuit, the input end of the DC-DC step-down circuit is connected to the power port of the signal receiving end, the output end of the DC-DC step-down circuit is connected to the power port of the signal sending end, and the DC-DC step-down circuit is a Buck topology structure. The DC-DC step-down circuit comprises an LV2842XLVDDCR type power chip.

2. The signal transmitting device of claim 1, wherein The output end of the DC-DC step-down circuit is connected to the feedback end through a seventh capacitor.

3. The signal transmitting device of claim 1, wherein The output end of the DC-DC step-down circuit is also connected to a filter circuit, the filter circuit comprises an eighth capacitor, a ninth capacitor and a ninth resistor, the first ends of the eighth capacitor and the ninth capacitor are connected to the output end of the DC-DC step-down circuit, the second ends of the eighth capacitor and the ninth capacitor are grounded, and the ninth resistor is connected between the second ends of the eighth capacitor and the ninth capacitor.

4. The signal transmitting device of claim 1, wherein The input end of the DC-DC step-down circuit is also connected to the ground through a fifth capacitor and a sixth capacitor in series.

5. The signal transmitting device of claim 1, wherein The signal amplification circuit comprises a first operational amplifier and a triode, wherein 6. The signal transmitting device of claim 1, wherein The non-inverting input end of the first operational amplifier is connected to the output end of the voltage follower circuit, the inverting input end of the first operational amplifier is grounded, the non-inverting input end of the first operational amplifier is also connected to the current signal output end of the signal amplification circuit through the fourth resistor and the sixth resistor in series, the positive power supply end of the first operational amplifier is connected to the second power supply input end of the signal amplification circuit, and the negative power supply end of the first operational amplifier is grounded. The base of the triode is connected to the output end of the first operational amplifier, the collector of the triode is connected to the first power supply input end of the signal amplification circuit, and the emitter of the triode is connected to the current signal output end of the signal amplification circuit through the fifth resistor and the seventh resistor in series. The middle node of the fifth resistor and the seventh resistor is grounded. The first power supply input end of the signal amplification circuit is connected to the input end of the DC-DC step-down circuit, and the second power supply input end of the signal amplification circuit is connected to the output end of the DC-DC step-down circuit. The first power supply input end of the signal amplification circuit is also connected to the current signal output end through the second capacitor and the third capacitor in series.

7. The signal transmitting device of claim 6, wherein The first resistor is connected in series between the positive power supply end of the first operational amplifier and the second power supply input end of the signal amplification circuit, and the positive power supply end of the first operational amplifier is also grounded through the first capacitor.

8. The signal transmitting device of claim 6, wherein ​ 9. The signal transmitting device of claim 6, wherein The signal transmission device comprises a twisted pair interface, and a current signal output end of the signal amplification circuit is connected to two signal ports of the twisted pair interface through two first diodes respectively, and the two signal ports of the twisted pair interface are further connected to a first power input end of the signal amplification circuit through two second diodes respectively.

10. The signal transmitting device of claim 6, wherein A second resistor is further connected in series in an input path of the first power input end of the signal amplification circuit.

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