Line loss compensation circuit

Abstract

The utility model discloses a line loss compensating circuit, which belongs to the technical field of voltage compensation and comprises a control chip U1, the cathode of the control chip U1 is sequentially connected with a resistor R5 and a resistor R3 in series and then is connected with the reference end of the control chip U1, and the anode of the control chip U1 is connected with a resistor R4 in series and is connected with the reference end of the control chip U1. Any point between the resistor R5 and the resistor R3 is connected with the positive electrode of the output end of the switching power supply through a first step-down circuit, any point between the resistor R5 and the resistor R3 is connected with the positive electrode of the input end of electric equipment, and any point between the positive electrode of the control chip U1 and the resistor R4 is connected with the negative electrode of the output end of the switching power supply through a second step-down circuit. Any point between the anode of the control chip U1 and the resistor R4 is connected with the cathode of the input end of the electric equipment; the actual voltage of the switching power supply reaching the electric equipment through the DC line is prevented from being lower than the nominal output voltage, and the use of the electric equipment is not affected.

Description

Technical Field

[0001] The utility model belongs to the technical field of voltage compensation, and particularly relates to a line loss compensation circuit. Background Art

[0002] In the application of switching power supplies, there are often relatively long output DC lines. As a conductor, the DC line itself has internal resistance. When the load is working, current flows through the DC line, and the internal resistance of the DC line will generate voltage loss, that is, line loss, so that the voltage at the end of the actual DC line is slightly lower than the voltage at the output end of the PCB. For some relatively precise instruments, the working voltage may need to be in a stable state, which poses requirements for how to compensate for line loss. Currently, the commonly used line loss compensation circuits widely adopt the circuit scheme of connecting two lines at the output end to sample the voltage of the electrical equipment. However, in the actual use process, when the cable for sampling the voltage of the electrical equipment is disconnected, the actual voltage reaching the electrical equipment will be lower than the nominal output voltage, affecting the use of the electrical equipment. Summary of the Utility Model

[0003] The purpose of the utility model is to address the above deficiencies in the prior art and provide a line loss compensation circuit to solve the problem that when the cable for sampling the voltage of the electrical equipment is disconnected during the actual use process, the actual voltage reaching the electrical equipment is lower than the nominal output voltage, affecting the use of the electrical equipment.

[0004] To achieve the above object, the technical solution adopted by the utility model is:

[0005] A line loss compensation circuit includes a control chip U1. The cathode of the control chip U1 is sequentially connected in series with a resistor R5 and a resistor R3 and then connected to the reference terminal of the control chip U1. The anode of the control chip U1 is connected in series with a resistor R4 to the reference terminal of the control chip U1. Any point between the resistor R5 and the resistor R3 is connected to the positive pole of the output terminal of the switching power supply through a first voltage reduction circuit. Any point between the resistor R5 and the resistor R3 is connected to the positive pole of the input terminal of the electrical equipment. Any point between the anode of the control chip U1 and the resistor R4 is connected to the negative pole of the output terminal of the switching power supply through a second voltage reduction circuit. Any point between the anode of the control chip U1 and the resistor R4 is connected to the negative pole of the input terminal of the electrical equipment.

[0006] In some embodiments, the control chip U1 is a TL431 chip.

[0007] In some embodiments, the first voltage reduction circuit includes a resistor R1, and the second voltage reduction circuit includes a resistor R2.

[0008] In some embodiments, the resistor values of the resistor R1 and the resistor R2 are the same.

[0009] In some embodiments, the first step-down circuit includes a diode D1, and the second step-down circuit includes a diode D2.

[0010] In some embodiments, the voltage drop values of the diode D1 and the diode D2 are the same.

[0011] A line loss compensation circuit provided by the present utility model has the following beneficial effects:

[0012] When the sampling cable at the input end of the electrical equipment is disconnected, the voltage after the first voltage sampled by the output end of the switching power supply is stepped down by the first step-down circuit and the second step-down circuit at the reference end of the TL431 chip participates in the feedback, so that the TL431 chip compensates for the line loss generated by the DC line internal resistance, avoiding that the actual voltage reaching the electrical equipment through the DC line is already lower than the nominal output voltage, and will not affect the use of the electrical equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 is a schematic diagram of the line loss compensation circuit of the present utility model;

[0014] Figure 2 is the line loss compensation circuit of the present utility model Figure 1 ;

[0015] Figure 3 is the line loss compensation circuit of the present utility model Figure 2 . DETAILED DESCRIPTION OF THE EMBODIMENTS

[0016] In order to make the objectives, technical solutions, and advantages of the present application clearer, the present application will be further described in detail below with reference to the accompanying drawings. The described embodiments should not be construed as limiting the present application. All other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the scope of protection of the present application.

[0017] In the following description, reference is made to "some embodiments", which describe a subset of all possible embodiments. However, it can be understood that "some embodiments" can be the same subset or different subsets of all possible embodiments, and can be combined with each other without conflict.

[0018] If similar descriptions such as "first / second / third" appear in the application documents, the following explanation is added. In the following description, the terms "first / second / third" involved are only used to distinguish similar objects and do not represent a specific order for the objects. It can be understood that "first / second / third" can be interchanged with a specific order or sequence when permitted, so that the embodiments of the present application described herein can be implemented in an order other than that illustrated or described herein.

[0019] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the technical field to which this application belongs. The terms used herein are for the purpose of describing embodiments of this application only and are not intended to limit this application.

[0020] Embodiment 1

[0021] This embodiment provides a line loss compensation circuit, as Figure 1 shown, including a control chip U1. The cathode of the control chip U1 is sequentially connected in series with a resistor R5 and a resistor R3 and then connected to the reference terminal of the control chip U1. The anode of the control chip U1 is connected in series with a resistor R4 to the reference terminal of the control chip U1. Any point between the resistor R5 and the resistor R3 is connected to the positive pole of the output terminal of the switching power supply through a first step-down circuit. Any point between the resistor R5 and the resistor R3 is connected to the positive pole of the input terminal of the electrical device. Any point between the anode of the control chip U1 and the resistor R4 is connected to the negative pole of the output terminal of the switching power supply through a second step-down circuit. Any point between the anode of the control chip U1 and the resistor R4 is connected to the negative pole of the input terminal of the electrical device. The control chip U1 is a TL431 chip.

[0022] In the embodiment of this application, the switching power supply and the electrical device are electrically connected through a DC line. The first step-down circuit and the second step-down circuit are used to step down the first voltage sampled at the output terminal of the switching power supply, so that the processed voltage is less than the second voltage sampled at the input terminal of the electrical device. Thus, the reference terminal of the TL431 chip preferentially participates in the feedback through the second voltage sampled at the input terminal of the electrical device, and then the voltage at the output terminal of the switching power supply is compensated through the TL431 chip. When the sampling cable at the input terminal of the electrical device is disconnected, the voltage after the first voltage sampled at the output terminal of the switching power supply is stepped down by the first step-down circuit and the second step-down circuit participates in the feedback at the reference terminal of the TL431 chip. Thus, the line loss generated by the internal resistance of the DC line is compensated through the TL431 chip, avoiding the actual voltage reaching the electrical device through the DC line from being lower than the nominal output voltage, and not affecting the use of the electrical device.

[0023] Embodiment 2

[0024] This embodiment provides a line loss compensation circuit, as Figure 2As shown, it includes a control chip U1. The cathode of the control chip U1 is sequentially connected in series with a resistor R5 and a resistor R3 and then connected to the reference terminal of the control chip U1. The anode of the control chip U1 is connected in series with a resistor R4 to the reference terminal of the control chip U1. Any point between the resistor R5 and the resistor R3 is connected to the positive pole of the output terminal of the switching power supply through a first voltage reduction circuit, and any point between the resistor R5 and the resistor R3 is connected to the positive pole of the input terminal of the electrical device. Any point between the anode of the control chip U1 and the resistor R4 is connected to the negative pole of the output terminal of the switching power supply through a second voltage reduction circuit, and any point between the anode of the control chip U1 and the resistor R4 is connected to the negative pole of the input terminal of the electrical device. The control chip U1 is a TL431 chip. The first voltage reduction circuit includes a resistor R1, and the second voltage reduction circuit includes a resistor R2. The resistance values of the resistor R1 and the resistor R2 are the same.

[0025] In the embodiment of the present application, the first voltage reduction circuit includes a resistor R1, the second voltage reduction circuit includes a resistor R2, the resistance values of the resistor R1 and the resistor R2 are the same, and both the resistor R1 and the resistor R2 can be composed of multiple resistors connected in series. The sampled voltage is reduced by the resistor R1 and the resistor R2. The resistance values of the resistor R1 and the resistor R2 can be determined according to the internal resistance of the DC line. The resistance values of the resistor R1 and the resistor R2 are greater than the internal resistance of the DC line. Different lengths of DC lines can be adapted by adjusting the resistance values of the resistor R1 and the resistor R2. The structure is simple and convenient to use.

[0026] Embodiment 3

[0027] This embodiment provides a line loss compensation circuit, as Figure 3 As shown, it includes a control chip U1. The cathode of the control chip U1 is sequentially connected in series with a resistor R5 and a resistor R3 and then connected to the reference terminal of the control chip U1. The anode of the control chip U1 is connected in series with a resistor R4 to the reference terminal of the control chip U1. Any point between the resistor R5 and the resistor R3 is connected to the positive pole of the output terminal of the switching power supply through a first voltage reduction circuit, and any point between the resistor R5 and the resistor R3 is connected to the positive pole of the input terminal of the electrical device. Any point between the anode of the control chip U1 and the resistor R4 is connected to the negative pole of the output terminal of the switching power supply through a second voltage reduction circuit, and any point between the anode of the control chip U1 and the resistor R4 is connected to the negative pole of the input terminal of the electrical device. The control chip U1 is a TL431 chip. The first voltage reduction circuit includes a diode D1, and the second voltage reduction circuit includes a diode D2. The voltage drop values of the diode D1 and the diode D2 are the same.

[0028] In the embodiment of the present application, the first step-down circuit includes diode D1, and the second step-down circuit includes diode D2. The step-down values of diode D1 and diode D2 are the same. Diode D1 and diode D2 can each be composed of multiple diodes connected in series. The sampled voltage is step-down processed by diode D1 and diode D2. The step-down values of diode D1 and diode D2 can be determined according to the internal resistance of the DC line. The step-down values of diode D1 and diode D2 are greater than the line loss generated by the internal resistance of the DC line. Different lengths of DC lines can be adapted by adjusting the step-down values of diode D1 and diode D2. The structure is simple, convenient and practical.

[0029] Although the specific embodiments of the utility model have been described in detail in conjunction with the accompanying drawings, it should not be construed as a limitation on the protection scope of this patent. Within the scope described in the claims, various modifications and deformations that can be made by those skilled in the art without creative efforts still fall within the protection scope of this patent.

Claims

1. A line loss compensation circuit, characterized in that: It includes a control chip U1, the cathode of the control chip U1 is connected in series with a resistor R5 and a resistor R3 in sequence and then connected to the reference end of the control chip U1, the anode of the control chip U1 is connected in series with a resistor R4 and connected to the reference end of the control chip U1, any point between the resistor R5 and the resistor R3 is connected to the positive electrode of the output end of the switching power supply through a first step-down circuit, any point between the resistor R5 and the resistor R3 is connected to the positive electrode of the input end of the electrical equipment, any point between the anode of the control chip U1 and the resistor R4 is connected to the negative electrode of the output end of the switching power supply through a second step-down circuit, and any point between the anode of the control chip U1 and the resistor R4 is connected to the negative electrode of the input end of the electrical equipment.

2. A line loss compensation circuit according to claim 1, characterized in that: The control chip U1 is a TL431 chip.

3. The line loss compensation circuit according to claim 1, characterized in that: The first step-down circuit includes a resistor R1, and the second step-down circuit includes a resistor R2.

4. A line loss compensation circuit according to claim 3, characterized in that: The resistance values ​​of the resistor R1 and the resistor R2 are the same.

5. The line loss compensation circuit according to claim 1, characterized in that: The first step-down circuit includes a diode D1 , and the second step-down circuit includes a diode D2 .

6. The line loss compensation circuit according to claim 5, characterized in that: The voltage drop value of the diode D1 is the same as that of the diode D2.

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