Adjustable resistance circuit capable of displaying resistance value

Abstract

The utility model relates to the technical field of resistance circuits, and particularly discloses an adjustable resistance circuit capable of displaying resistance values. Comprising a processor circuit, an encoder circuit, a nixie tube display driving circuit, an I / O port expansion circuit, a relay control circuit and a power conversion circuit. The encoder circuit adjusts the numerical value of a five-bit nixie tube in the nixie tube display driving circuit through a rotary encoder so as to adjust the resistance value of the target output impedance, and the nixie tube in the nixie tube display driving circuit sequentially corresponds to the tenth bit, the thousand bit, the hundred bit, the ten bit and the unit bit of the resistance value from left to right; the I / O port expansion circuit is provided with I / O port expansion chips, each I / O port expansion chip can be expanded to form 16 I / O ports, the adjustable resistance circuit totally uses 6 I / O port expansion chips, and the adjustable resistance circuit is expanded to form 90 I / O ports; and the relay control circuit realizes the adjustment of a resistance value of 1 ohm to 99.999 kilohm through 45 resistors. The adjustable resistor circuit is simple and easy to implement.

Description

Technical Field

[0001] The utility model relates to the technical field of resistor circuits, in particular to an adjustable resistor circuit that displays resistance values. Background Art

[0002] Resistors are the most commonly used components in circuits. They are widely used in a wide range of applications and have various parameter requirements. Currently, the commonly used devices on the market that can directly adjust the resistance value are mostly adjustable resistors / potentiometers, or the parallel value of multiple resistors and the series value of multiple resistors are connected in parallel to achieve the purpose of adjusting the resistance value. This method has a complex circuit and the resistance accuracy is not easy to adjust.

[0003] For example, the Chinese patent with publication number CN102693796A discloses a digital adjustable resistor and its adjustment method, which is through parallel controlled resistor string and adjustment resistor string, and then series connected with more than or equal to 1 group of parallel controlled resistor string and adjustment resistor string, wherein the controlled resistor string obtains the approximate value of the required resistance by adjusting the number of parallel resistors, and the adjustment resistor string adjusts the resistance value of the digital adjustable resistor by adjusting the number of series resistors, and finally obtains the required resistance. If this method is used to output a resistance value of 90kΩ, 90 groups of parallel controlled resistor strings and adjustment resistor strings need to be connected in series, and the actual application is obviously unrealistic. This method is not easy to calculate the target resistance value, the adjustable resistance accuracy is not easy to control, and the realization of wide range resistance adjustment requires many circuit components and the software implementation is cumbersome; direct drive with a single-chip microcomputer will use more chip I / O pins, it is difficult to select the model of the single-chip microcomputer, and the cost of the single-chip microcomputer is expensive. Utility Model Content

[0004] Based on this, the purpose of the utility model is to provide an adjustable resistor circuit that displays resistance value in view of the deficiencies in the prior art.

[0005] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0006] An adjustable resistor circuit for displaying resistance value, characterized in that it comprises a processor circuit, an encoder circuit, a digital tube display drive circuit, an I / O port expansion circuit, a relay control circuit, and a power conversion circuit;

[0007] The relay control circuit adjusts the resistance value of 1Ω-99.999KΩ through 45 resistors, the resistance value adjustment step of the adjustable resistor circuit is 1Ω, the 45 resistors are divided into five ohm levels, the five ohm levels are respectively the ones ohm level, the tens ohm level, the hundreds ohm level, the thousands ohm level and the ten thousand ohm level, and the five ohm levels are each provided with 9 resistors of the corresponding ohm level;

[0008] The nine resistors of each ohm level of the five ohm-level resistors are connected in parallel respectively; the ones-digit ohm-level resistors are connected in parallel and connected in series with the tens-digit ohm-level resistors through S1; the tens-digit ohm-level resistors are connected in parallel and connected in series with the hundreds-digit ohm-level resistors through S2; the hundreds-digit ohm-level resistors are connected in parallel and connected in series with the thousands-digit ohm-level resistors through S3; the thousands-digit ohm-level resistors are connected in parallel and connected in series with the tens-digit ohm-level resistors through S4; the output impedance is derived from S0 and S5;

[0009] The encoder circuit adjusts the numerical value of the 5-digit digital tube in the digital tube display driving circuit by rotating the encoder, thereby adjusting the resistance value of the target output impedance. The digital tubes in the digital tube display driving circuit correspond to the ten thousand digit, thousand digit, hundred digit, ten digit, and unit digit of the resistance value from left to right.

[0010] As a further improvement of the present invention, the resistance accuracy selected in the relay control circuit is 1%, and the output impedance error of the adjustable resistance circuit is ≤1%.

[0011] As a further improvement of the utility model, the processor circuit can interact with the encoder circuit, the digital tube display circuit, the I / O port expansion circuit, and the relay control circuit to perform data processing and signal processing.

[0012] As a further improvement of the present invention, the I / O port expansion chip provided on the I / O port expansion circuit needs to communicate data with the single-chip microcomputer provided on the processor circuit through three lines: SCL, SDA, and INT#.

[0013] As a further improvement of the utility model, the I / O port expansion circuit is provided with an I / O port expansion chip, each of which can expand 16 I / O ports, and the adjustable resistor circuit uses a total of 6 I / O port expansion chips, and the adjustable resistor circuit expands 90 I / O ports.

[0014] As a further improvement of the present invention, the rotary encoder in the encoder circuit can adjust the target resistance value by directly rotating the rotary encoder; it can also be achieved by pressing the rotary encoder to select the bit to be adjusted, and then rotating the rotary encoder to adjust the value of the corresponding bit, thereby realizing rapid adjustment of the target impedance.

[0015] As a further improvement of the utility model, after a numerical value of a digital tube in the digital tube display driving circuit is determined, pressing the encoder shaft is used for confirmation, and the adjustable resistance circuit automatically enters the selection of the next numerical value.

[0016] As a further improvement of the present invention, the LED display driver chip in the digital tube display driver circuit and the single chip microcomputer in the processor circuit are connected via I 2C interface communication, the single chip microcomputer sends instructions according to the resistance adjustment signal received from the encoder circuit to control the digital tube in the digital tube display driving circuit to display the corresponding resistance value.

[0017] As a further improvement of the utility model, one resistor of the adjustable resistance circuit corresponds to two relays, and the relays are controlled by MOS tubes. When the relays are in the default state, the pin is at 5-3, which is defined as the switch is closed; when the relays are triggered, the pin is at 5-2, which is defined as the switch is open; the MOS tube includes a MOS gate, and when the MOS gate is connected to a high level, the relay switch state is controlled to be open.

[0018] As a further improvement of the utility model, the power conversion circuit provides working power for the processor circuit, encoder circuit, digital tube display drive circuit, I / O port expansion circuit, and relay control circuit, and an external power supply can be connected to the circuit through the DC1 interface.

[0019] The beneficial effects of the utility model are:

[0020] 1. The adjustable resistor circuit in the present application can manually adjust the resistance value of the resistor, and the digital tube in the digital tube display driving circuit displays the size of the selected resistance value.

[0021] 2. The adjustable resistor circuit in this application can achieve an output impedance of 0Ω or infinity; the resistance value adjustment range of the adjustable resistor circuit is 1Ω-99.999KΩ.

[0022] 3. The control switch of the adjustable resistance circuit in this application connected to the resistance output loop is a relay, whose internal resistance is almost 0 and can be ignored, and the accuracy of the actual impedance output is higher.

[0023] 4. The adjustable resistor circuit in this application is simple, and the I / O port expansion circuit greatly reduces the hardware requirements for the number of microcontroller I / O ports. Software programming does not require a lot of calculations and is easy to implement. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0025] Attached Figure 1 The utility model is a schematic diagram of the overall structure of the adjustable resistance circuit.

[0026] Attached Figure 2This is a schematic diagram of the principle of the processor circuit of the utility model.

[0027] Attached Figure 3 This is a schematic diagram of the principle of the encoder circuit of the utility model.

[0028] Attached Figure 4 The figure is a schematic diagram of the principle of the digital tube display driving circuit of the utility model.

[0029] Attached Figure 5 The utility model is a schematic diagram of the principle of the I / O port expansion circuit.

[0030] Attached Figure 6 The utility model is a schematic diagram of the principle of the relay control circuit.

[0031] Attached Figure 7 It is a schematic diagram of the principle of the power conversion circuit of the utility model. DETAILED DESCRIPTION

[0032] The technical solutions in the embodiments of the utility model will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of them. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0033] like Figure 1-6 As shown, an adjustable resistor circuit for displaying resistance value includes a processor circuit, an encoder circuit, a digital tube display drive circuit, an I / O port expansion circuit, a relay control circuit, and a power conversion circuit;

[0034] In a specific embodiment, further, the processor circuit can interact with the encoder circuit, the digital tube display circuit, the I / O port expansion circuit, and the relay control circuit to perform data exchange and process signals.

[0035] In a specific embodiment, further, the encoder circuit adjusts the value of the 5-digit digital tube in the digital tube display driving circuit by rotating the encoder, thereby adjusting the resistance value of the target output impedance, and the digital tubes in the digital tube display driving circuit correspond to the ten thousand digit, thousand digit, hundred digit, ten digit, and unit digit of the resistance value from left to right;

[0036] In a specific embodiment, further, after a numerical value of a digital tube in the digital tube display driving circuit is determined, pressing the encoder shaft is used for confirmation, and the adjustable resistance circuit automatically enters the selection of the next numerical value.

[0037] In a specific embodiment, further, the LED display driver chip in the digital tube display driver circuit and the single chip microcomputer in the processor circuit are connected via I 2 C interface communication, the single chip microcomputer sends instructions according to the resistance adjustment signal received from the encoder circuit to control the digital tube in the digital tube display driving circuit to display the corresponding resistance value.

[0038] In a specific embodiment, further, the I / O port expansion circuit is provided with an I / O port expansion chip, each of which can expand 16 I / O ports, and the adjustable resistance circuit uses a total of 6 I / O port expansion chips, and the adjustable resistance circuit expands 90 I / O ports.

[0039] In a specific embodiment, further, the I / O port expansion chip provided on the I / O port expansion circuit needs to communicate data with the single-chip microcomputer provided on the processor circuit through three lines: SCL, SDA, and INT#.

[0040] In a specific embodiment, further, the relay control circuit adjusts the resistance value of 1Ω-99.999KΩ through 45 resistors.

[0041] In a specific embodiment, further, the relay control circuit realizes the adjustment of the resistance value of 1Ω-99.999KΩ through 45 resistors, the resistance value adjustment step of the adjustable resistor circuit is 1Ω, the 45 resistors are divided into five ohm levels, and the five ohm levels are respectively the ones ohm level, the tens ohm level, the hundreds ohm level, the thousands ohm level and the ten thousand ohm level, and the five ohm levels are each provided with 9 resistors of the corresponding ohm level;

[0042] The nine resistors of each ohm level of the five ohm-level resistors are connected in parallel respectively; the ones-digit ohm-level resistors are connected in parallel and connected in series with the tens-digit ohm-level resistors through S1; the tens-digit ohm-level resistors are connected in parallel and connected in series with the hundreds-digit ohm-level resistors through S2; the hundreds-digit ohm-level resistors are connected in parallel and connected in series with the thousands-digit ohm-level resistors through S3; the thousands-digit ohm-level resistors are connected in parallel and connected in series with the tens-digit ohm-level resistors through S4; the output impedance is derived from S0 and S5;

[0043] The resistance value of the target resistor = the resistance value of the ten thousand digit + the resistance value of the thousand digit + the resistance value of the hundred digit + the resistance value of the ten digit + the resistance value of the unit digit. For example, the resistance value of the target resistor is 65.378K, and the ten thousand digit of the resistance value 65.378K is 6, the thousand digit is 5, the hundred digit is 3, the ten digit is 7, and the unit digit is 8, that is, 60KΩ+5KΩ+300Ω+70Ω+8Ω.

[0044] In a specific embodiment, further, one resistor of the adjustable resistance circuit corresponds to two relays, and the relays are controlled by MOS tubes. When the relay is in the default state, the pin is at 5-3, which is defined as the switch is closed; when the relay is triggered, the pin is at 5-2, which is defined as the switch is open. Figure 6 As shown; the MOS tube includes a MOS gate. When the MOS gate is connected to a high level, the switch state of the control relay is turned on.

[0045] In a specific embodiment, further, the resistance accuracy selected in the relay control circuit is 1%, and the output impedance error of the adjustable resistance circuit is ≤1%.

[0046] In a specific embodiment, further, the power conversion circuit provides working power for the processor circuit, encoder circuit, digital tube display drive circuit, I / O port expansion circuit, and relay control circuit, and an external power supply can be connected to the circuit through a DC1 interface.

[0047] In a specific embodiment, further, the rotary encoder in the encoder circuit can adjust the target resistance value by directly rotating the rotary encoder; it can also be achieved by pressing the rotary encoder to select the bit to be adjusted, and then rotating the rotary encoder to adjust the value of the corresponding bit, thereby achieving rapid adjustment of the target impedance.

[0048] The operator rotates the encoder in the digital tube display drive circuit to select the digital tube display value (range is 1Ω-99.999KΩ, step is 1Ω), that is, the target resistance value. The single-chip microcomputer in the processor circuit analyzes the resistance values ​​of the ten thousand digit, thousand digit, hundred digit, ten digit and unit digit of the target resistance value to determine the circuit conduction loop. The single-chip microcomputer in the processor circuit issues a command to open or close the relay switch that controls the ten thousand digit, thousand digit, hundred digit, ten digit and unit digit resistance.

[0049] It can be understood that the above specific description of the utility model is only used to illustrate the utility model and is not limited to the technical solution described in the embodiments of the utility model. Ordinary technicians in the field should understand that the utility model can still be modified or replaced by equivalents to achieve the same technical effect; as long as the use requirements are met, they are within the protection scope of the utility model.

[0050] Finally, it should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the presence of other identical elements in the process, method, article or device including the elements.

Claims

1. An adjustable resistor circuit for displaying resistance value, characterized in that: It includes processor circuit, encoder circuit, digital tube display drive circuit, I / O port expansion circuit, relay control circuit and power conversion circuit; The relay control circuit adjusts the resistance value of 1Ω-99.999KΩ through 45 resistors, the resistance value adjustment step of the adjustable resistor circuit is 1Ω, the 45 resistors are divided into five ohm levels, the five ohm levels are respectively the ones ohm level, the tens ohm level, the hundreds ohm level, the thousands ohm level and the ten thousand ohm level, and the five ohm levels are each provided with 9 resistors of the corresponding ohm level; The nine resistors of each ohm level of the five ohm-level resistors are connected in parallel respectively; the ones-digit ohm-level resistors are connected in parallel and connected in series with the tens-digit ohm-level resistors through S1; the tens-digit ohm-level resistors are connected in parallel and connected in series with the hundreds-digit ohm-level resistors through S2; the hundreds-digit ohm-level resistors are connected in parallel and connected in series with the thousands-digit ohm-level resistors through S3; the thousands-digit ohm-level resistors are connected in parallel and connected in series with the tens-digit ohm-level resistors through S4; the output impedance is derived from S0 and S5; The encoder circuit adjusts the numerical value of the 5-digit digital tube in the digital tube display driving circuit by rotating the encoder, thereby adjusting the resistance value of the target output impedance. The digital tubes in the digital tube display driving circuit correspond to the ten thousand digit, thousand digit, hundred digit, ten digit, and unit digit of the resistance value from left to right.

2. The adjustable resistance circuit according to claim 1, characterized in that: The resistance accuracy selected in the relay control circuit is 1%, and the output impedance error of the adjustable resistance circuit is ≤1%.

3. The adjustable resistance circuit according to claim 1, characterized in that: The processor circuit can perform data interaction with the encoder circuit, the digital tube display circuit, the I / O port expansion circuit, and the relay control circuit to process signals.

4. The adjustable resistance circuit according to claim 1, characterized in that: The I / O port expansion chip provided on the I / O port expansion circuit needs to perform data communication with the single-chip microcomputer provided on the processor circuit through three lines: SCL, SDA, and INT#.

5. The adjustable resistance circuit according to claim 4, characterized in that: The I / O port expansion circuit is provided with an I / O port expansion chip, each of which can expand 16 I / O ports. The adjustable resistor circuit uses a total of 6 I / O port expansion chips, and the adjustable resistor circuit expands 90 I / O ports.

6. The adjustable resistance circuit according to claim 1, characterized in that: The rotary encoder in the encoder circuit adjusts the target resistance value by directly rotating the rotary encoder.

7. The adjustable resistance circuit according to claim 1, characterized in that: The rotary encoder in the encoder circuit selects the bit to be adjusted by pressing the rotary encoder, and then rotates the rotary encoder to adjust the value of the corresponding bit, thereby realizing rapid adjustment of the target impedance.

8. The adjustable resistance circuit according to claim 1, characterized in that: After a numerical value of a digital tube in the digital tube display driving circuit is determined, pressing the encoder shaft is confirmation, and the adjustable resistance circuit automatically enters the selection of the next numerical value.

9. The adjustable resistance circuit according to claim 8, characterized in that: The LED display driver chip in the digital tube display driver circuit and the single chip microcomputer in the processor circuit are connected via I 2 C interface communication, the single chip microcomputer sends instructions according to the resistance adjustment signal received from the encoder circuit to control the digital tube in the digital tube display driving circuit to display the corresponding resistance value.

10. The adjustable resistance circuit according to claim 1, characterized in that: One resistor of the adjustable resistance circuit corresponds to two relays, and the relay is controlled by a MOS tube. When the relay is in the default state, the pin is at 5-3, which is defined as the switch is closed; when the relay is triggered, the pin is at 5-2, which is defined as the switch is open; the MOS tube includes a MOS gate, and when the MOS gate is connected to a high level, the relay switch state is controlled to be open.

11. The adjustable resistance circuit according to claim 1, characterized in that: The power conversion circuit provides working power for the processor circuit, encoder circuit, digital tube display drive circuit, I / O port expansion circuit, and relay control circuit, and an external power supply can be connected to the circuit through a DC1 interface.

Images