Voltage divider and control method thereof

Abstract

The present invention discloses a voltage divider and a control method thereof. The voltage divider includes: an input voltage terminal, a ground terminal, a switching switch, a first resistor, a second resistor, an intermediate capacitor, and an output voltage terminal; the switching switch includes four wiring terminals, which are respectively connected to the input voltage terminal, the ground terminal, the first end of the first resistor, and the first end of the second resistor; the second end of the first resistor and the second end of the second resistor are connected to the first end of the intermediate capacitor; the second end of the intermediate capacitor is grounded; and the output voltage terminal is connected to the first end of the intermediate capacitor. The switching switch switches the connection relationship of the four wiring terminals to achieve circuit switching between the input voltage terminal and the ground terminal, so that the voltage across the intermediate capacitor is half of the input voltage and is output by the output voltage terminal. The present invention can reduce the voltage divider ratio error caused by resistor tolerance, so that the voltage divider can achieve high-accuracy voltage division based on conventional low-cost resistors.

Description

Technical Field

[0001] The present invention relates to the field of circuit technology, and in particular to a voltage divider and a control method thereof. Background Art

[0002] This section is intended to provide a background or context to the embodiments of the invention that are recited in the claims. No statement herein is admitted to be prior art by virtue of its inclusion in this section.

[0003] A voltage divider is a device that converts a higher voltage into a lower voltage at a specific ratio. It's often used in voltage circuits and voltage measurements. The simplest voltage divider consists of n resistors connected in series. A primary voltage is applied to the tops of the n resistors, and the output from the lower resistor is 1 / n of the primary voltage.

[0004] In metrology, a 1 / 2 voltage divider is often used to achieve a binary voltage divider ratio through cascading switches. However, due to the tolerances of the two resistors in the voltage divider, the voltage divider ratio may have errors. To achieve a low-error voltage divider ratio, better voltage divider resistors are required in practice. However, such resistors are often expensive. Therefore, how to provide a voltage divider that can achieve high-accuracy voltage divider ratio conversion using low-cost resistors is an urgent problem in this field.

[0005] To address the above issues, no effective solutions have been proposed so far. Summary of the Invention

[0006] A voltage divider is provided in an embodiment of the present invention to solve the technical problem that an existing resistor voltage divider may cause an error in the voltage divider ratio due to the influence of resistor tolerance. The voltage divider includes: an input voltage terminal, a ground terminal, a switching switch, a first resistor, a second resistor, an intermediate capacitor and an output voltage terminal; wherein the switching switch includes: a first terminal, a second terminal, a third terminal and a fourth terminal; the first terminal is connected to the input voltage terminal; the second terminal is connected to the ground terminal; the third terminal is connected to the first end of the first resistor; the fourth terminal is connected to the first end of the second resistor; the second end of the first resistor and the second end of the second resistor are connected to the first end of the intermediate capacitor; the second end of the intermediate capacitor is grounded; the output voltage terminal is connected to the first end of the intermediate capacitor; wherein the input voltage terminal is used to connect to a DC voltage; the ground terminal is used to be grounded; the switching switch is used to realize circuit switching between the input voltage terminal and the ground terminal by switching the connection relationship between the first terminal, the second terminal, the third terminal and the fourth terminal; the output voltage terminal is used to output the voltage across the intermediate capacitor.

[0007] An embodiment of the present invention also provides a control method for a voltage divider. The method is applied to the above-mentioned voltage divider to solve the technical problem that the voltage divider ratio of the existing resistor voltage divider has an error due to the influence of the resistor tolerance. The method includes: outputting a square wave signal of a preset frequency; according to the square wave signal, controlling the switching switch to switch the connection relationship between the first terminal, the second terminal, the third terminal and the fourth terminal to realize circuit switching between the input voltage terminal and the ground terminal.

[0008] A computer device is also provided in an embodiment of the present invention to solve the technical problem that the voltage divider ratio of the existing resistor divider has an error due to the influence of the resistor tolerance. The computer device includes a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the control method of the voltage divider is implemented.

[0009] An embodiment of the present invention further provides a computer-readable storage medium for solving the technical problem that the voltage divider ratio of the existing resistor voltage divider may have errors due to the influence of resistor tolerance. The computer-readable storage medium stores a computer program for executing the control method of the above-mentioned voltage divider.

[0010] In an embodiment of the present invention, a voltage divider based on a switching switch is provided. By switching the connection relationship between the first terminal, the second terminal, the third terminal, and the fourth terminal, the input voltage terminal of the voltage divider is connected to the first resistor or the second resistor, and the ground terminal is connected to the second resistor or the first resistor, thereby realizing circuit switching between the input voltage terminal and the ground terminal. This enables the voltage across the intermediate capacitor to be half of the input voltage and output from the output voltage terminal of the voltage divider. Compared with the resistor voltage divider provided in the prior art, the embodiment of the present invention can reduce the voltage divider ratio error caused by resistor tolerance, so that the voltage divider can achieve high-accuracy voltage division based on conventional low-cost resistors. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative work. In the drawings:

[0012] Figure 1 A schematic diagram of a voltage divider provided in the prior art;

[0013] Figure 2 A schematic diagram of a voltage divider provided in an embodiment of the present invention;

[0014] Figure 3A schematic diagram of an optional voltage divider provided in an embodiment of the present invention;

[0015] Figure 4 This is a flow chart of a control method for a voltage divider provided in an embodiment of the present invention;

[0016] Figure 5 A schematic diagram of a computer device provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0017] To make the purpose, technical solutions and advantages of the embodiments of the present invention more clear, the embodiments of the present invention are further described in detail below with reference to the accompanying drawings. Here, the exemplary embodiments of the present invention and their descriptions are used to explain the present invention, but are not intended to limit the present invention.

[0018] Figure 1 A resistor divider provided in the prior art is shown. Figure 1 As shown, R1 and R2 are voltage divider resistors, U1 is the primary voltage, and U2 is the output voltage.

[0019] Assuming that the tolerances of R1 and R2 are α and β respectively, then Figure 1 The error ε of the voltage divider ratio K of the voltage divider shown is:

[0020]

[0021] If R1 and R2 are of equal rating, then:

[0022]

[0023] It can be seen that as a 1 / 2 voltage divider, its error is approximately half of the difference in the tolerances of the two resistors.

[0024] From the above analysis, it can be seen that the voltage divider ratio error of the resistor divider depends on the resistors used. If a high-accuracy voltage divider is to be implemented, it is necessary to use relatively expensive precision resistors, which is costly.

[0025] In order to solve the problem that the voltage dividing ratio of a 1 / 2 resistor voltage divider is affected by the tolerance of the voltage dividing resistor, an embodiment of the present invention provides a voltage divider that can achieve high-accuracy voltage division based on conventional low-cost resistors.

[0026] Figure 2 Schematic diagram of a voltage divider provided in an embodiment of the present invention, such as Figure 2 As shown, the voltage divider includes: an input voltage terminal 1, a ground terminal 2, a switch 3, a first resistor 401, a second resistor 402, an intermediate capacitor 5 and an output voltage terminal 6;

[0027] The switch 3 includes a first terminal 301, a second terminal 302, a third terminal 303, and a fourth terminal 304; the first terminal 301 is connected to the input voltage terminal 1; the second terminal 302 is connected to the ground terminal 2; the third terminal 303 is connected to the first end of the first resistor 401; the fourth terminal 304 is connected to the first end of the second resistor 402; the second end of the first resistor 401 and the second end of the second resistor 402 are connected to the first end of the intermediate capacitor 5; the second end of the intermediate capacitor 5 is grounded; and the output voltage terminal 6 is connected to the first end of the intermediate capacitor 5.

[0028] Among them, the input voltage terminal 1 is used to connect to the DC voltage; the ground terminal 2 is used for grounding; the switching switch 3 is used to realize the circuit switching of the input voltage terminal 1 and the ground terminal 2 by switching the connection relationship between the first terminal 301, the second terminal 302, the third terminal 303 and the fourth terminal 304; the output voltage terminal 6 is used to output the voltage across the intermediate capacitor 5.

[0029] In a specific implementation, the switch 3 used in the embodiment of the present invention may be a MAX14759 analog switch.

[0030] The following combination Figure 2 The working principle of the embodiment of the present invention is described in detail:

[0031] like Figure 2 As shown, when the voltage divider is working, in the initial state, the first resistor 401 (ie R1) and the second resistor 402 (ie R2) are connected to the input voltage terminal 1 and the ground terminal 2 respectively through the switch 3, and the voltage obtained by the intermediate capacitor 5 is U C1 :

[0032]

[0033] Among them, R S1 and R S2 is the on-resistance of the switch 3.

[0034] Switch to Figure 2 In the dotted channel shown in FIG, the first resistor 401 and the second resistor 402 are connected to the ground terminal 2 and the input voltage terminal 1 respectively through the switch 3, and the voltage obtained by the intermediate capacitor 5 is U C2 :

[0035]

[0036] Among them, R S3 and R S4 is the on-resistance of the analog switch.

[0037] In this way, the switch 3 is continuously controlled to switch according to a certain frequency, and the voltage across the intermediate capacitor 5 will be U C1 and U C2 The average value of , so we have:

[0038]

[0039] For the on-resistance of switch 3, the power supply voltage is the same, and the consistency of on-resistance of each switch in the same chip is very high, generally less than 1ppm, so it can be considered that R S1 =R S3 , R S2 =R S4 For this we can obtain:

[0040]

[0041] In one embodiment, Figure 3 As shown, the voltage divider provided in the embodiment of the present invention may also include: a voltage follower 7 composed of a third resistor 701 (i.e., R3), a fourth resistor 702 (i.e., R4) and an operational amplifier 703; wherein the first end of the third resistor 701 is connected to the first end of the intermediate capacitor 5; the second end of the third resistor 701 is connected to the positive input terminal of the operational amplifier 703; the first end of the fourth resistor 702 is connected to the output terminal of the operational amplifier 703, and the second end of the fourth resistor 702 is connected to the negative input terminal of the operational amplifier 703; the output terminal of the operational amplifier 703 is connected to the output voltage terminal 6.

[0042] It should be noted that because a voltage follower has high input impedance and low output impedance, it is incorporated into the circuit to provide a buffering effect, preventing a significant portion of the signal from being lost in the output resistor of the preceding stage. Furthermore, by increasing the input impedance, the input capacitor can be significantly reduced, thus ensuring the use of high-quality capacitors.

[0043] Optionally, in the embodiment of the present invention, the operational amplifier 703 uses an OPA140 chip with a low bias voltage.

[0044] In one embodiment, the voltage divider provided in the embodiment of the present invention may further include: a controller ( Figure 2 and Figure 3 ), connected to the switch 3, and used to control the switch 3 to switch the connection relationship among the first terminal 301, the second terminal 302, the third terminal 303 and the fourth terminal 304.

[0045] like Figure 3As shown, in a specific implementation, the controller can output a square wave signal of a preset frequency to the switch 3, and control the switch 3 to switch the connection relationship between the first terminal 301, the second terminal 302, the third terminal 303 and the fourth terminal 304 through the square wave signal.

[0046] In a specific implementation, the voltage divider provided in the embodiment of the present invention may adopt the following parameters:

[0047] The voltage divider's input voltage terminal 1 is connected to a 5V DC voltage. The first and second resistors 401 and 402 are 100kΩ resistors; the third resistor 701 is 470Ω; and the fourth resistor 702 is 50kΩ. The intermediate capacitor 5 is 0.1μF. The frequency of the square wave signal controlling the switch is 100kHz. Because the switching interval of the switch is in the nanosecond range, the voltage change on the capacitor during the switching period can be ignored.

[0048] It can be found from the above formula (6) that the voltage divider provided in the embodiment of the present invention, even if the first resistor 401 and the second resistor 402 are ordinary chip resistors with a tolerance of 1%, the switching between the input terminal and the ground terminal of the voltage divider is completed by switching the switch 3. In conjunction with the intermediate capacitor 5, before and after switching, the voltage obtained across the intermediate capacitor 5 can be half of the input voltage, and has an error of at most 1-2 ppm.

[0049] Based on the same inventive concept, an embodiment of the present invention further provides a method for controlling a voltage divider, which can be applied to the voltage divider described in any of the above embodiments.

[0050] Figure 4 FIG. 1 is a flow chart of a control method for a voltage divider provided in an embodiment of the present invention, such as Figure 4 As shown, the method includes the following steps:

[0051] S401, outputting a square wave signal of a preset frequency;

[0052] S402 , according to the square wave signal, controlling the switch to switch the connection relationship between the first terminal, the second terminal, the third terminal, and the fourth terminal, so as to implement circuit switching between the input voltage terminal and the ground terminal.

[0053] It should be noted that the solutions provided in the above S401 to S402 can be implemented by a controller built into a voltage divider, or by a controller connected to a switch in the voltage divider.

[0054] Based on the same inventive concept, an embodiment of the present invention further provides a computer device to solve the technical problem that the voltage divider ratio of the existing resistor divider may have an error due to the influence of the resistor tolerance. Figure 5A schematic diagram of a computer device provided in an embodiment of the present invention is shown in FIG. Figure 5 As shown, the computer device 50 includes a memory 501, a processor 502, and a computer program stored in the memory 501 and executable on the processor 502. When the processor 502 executes the computer program, the above-mentioned voltage divider control method is implemented.

[0055] Based on the same inventive concept, an embodiment of the present invention further provides a computer-readable storage medium for solving the technical problem that the voltage divider ratio of the existing resistor voltage divider may have errors due to the influence of resistor tolerance. The computer-readable storage medium stores a computer program for executing the control method of the above-mentioned voltage divider.

[0056] In summary, embodiments of the present invention provide a voltage divider and a control method thereof, a computer device, and a computer-readable storage medium. By switching the connection relationship between the first terminal, the second terminal, the third terminal, and the fourth terminal through a switching switch, the input voltage terminal of the voltage divider is connected to the first resistor or the second resistor, and the ground terminal is connected to the second resistor or the first resistor, thereby realizing circuit switching of the input voltage terminal and the ground terminal. This enables the voltage across the intermediate capacitor to be half of the input voltage and output from the output voltage terminal of the voltage divider. Compared with the resistor voltage divider provided in the prior art, the voltage divider based on the switching switch provided in the embodiments of the present invention can reduce the voltage divider ratio error caused by the resistor tolerance, so that the voltage divider can achieve high-accuracy voltage division based on conventional low-cost resistors.

[0057] It will be understood by those skilled in the art that embodiments of the present invention may be provided as methods, systems, or computer program products. Thus, the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware. Furthermore, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to magnetic disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0058] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowcharts and / or block diagrams, as well as combinations of processes and / or blocks in the flowcharts and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowcharts and / or block diagrams. Figure 1 a process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0059] These computer program instructions may also be stored in a computer readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 a process or multiple processes and / or boxes Figure 1 The function specified in one or more boxes.

[0060] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operational steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing the instructions executed on the computer or other programmable device for implementing the process. Figure 1 a process or multiple processes and / or boxes Figure 1 A step that specifies a function in one or more boxes.

[0061] The specific embodiments described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A voltage divider, characterized in that: include: An input voltage terminal (1), a ground terminal (2), a switch (3), a first resistor (401), a second resistor (402), an intermediate capacitor (5), and an output voltage terminal (6); The switching switch (3) comprises: a first terminal (301), a second terminal (302), a third terminal (303) and a fourth terminal (304); the first terminal (301) is connected to the input voltage terminal (1); the second terminal (302) is connected to the ground terminal (2); the third terminal (303) is connected to the first end of the first resistor (401); the fourth terminal (304) is connected to the first end of the second resistor (402); the second end of the first resistor (401) and the second end of the second resistor (402) are connected to the first end of the intermediate capacitor (5); the second end of the intermediate capacitor (5) is grounded; and the output voltage terminal (6) is connected to the first end of the intermediate capacitor (5); The input voltage terminal (1) is used to connect to a DC voltage; the ground terminal (2) is used to connect to the ground; the switch (3) is used to switch the connection relationship between the first terminal (301), the second terminal (302), the third terminal (303) and the fourth terminal (304) to achieve circuit switching between the input voltage terminal (1) and the ground terminal (2); the output voltage terminal (6) is used to output the voltage across the intermediate capacitor (5); The invention also includes a controller connected to the switching switch (3) and configured to output a square wave signal of a preset frequency to the switching switch (3), and to control the switching switch (3) to switch the connection relationship among the first terminal (301), the second terminal (302), the third terminal (303) and the fourth terminal (304) through the square wave signal.

2. The voltage divider according to claim 1, wherein The voltage divider further comprises: a voltage follower (7) composed of a third resistor (701), a fourth resistor (702) and an operational amplifier (703); The first end of the third resistor (701) is connected to the first end of the intermediate capacitor (5); the second end of the third resistor (701) is connected to the positive input end of the operational amplifier (703); the first end of the fourth resistor (702) is connected to the output end of the operational amplifier (703), and the second end of the fourth resistor (702) is connected to the negative input end of the operational amplifier (703); and the output end of the operational amplifier (703) is connected to the output voltage terminal (6).

3. The voltage divider according to claim 2, wherein The operational amplifier (703) is an OPA140 chip.

4. The voltage divider according to claim 2, wherein: The resistance of the third resistor (701) is 470Ω; and the resistance of the fourth resistor (702) is 50kΩ.

5. The voltage divider according to claim 1, wherein The switching switch (3) is a MAX14759 analog switch.

6. The voltage divider according to claim 1, wherein The resistance of the first resistor (401) and the second resistor (402) is 100 kΩ.

7. The voltage divider according to claim 1, wherein The capacitance value of the intermediate capacitor (5) is 0.1 μF.

8. A method for controlling a voltage divider, characterized in that: The method is applied to the voltage divider according to any one of claims 1 to 7, comprising: Output a square wave signal of a preset frequency; According to the square wave signal, the switching switch (3) is controlled to switch the connection relationship between the first terminal (301), the second terminal (302), the third terminal (303) and the fourth terminal (304), thereby realizing circuit switching between the input voltage terminal (1) and the ground terminal (2).

9. A computer device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein: When the processor executes the computer program, the voltage divider control method according to claim 8 is implemented.

10. A computer-readable storage medium, characterized in that The computer-readable storage medium stores a computer program for executing the voltage divider control method according to claim 8 .

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