Voltage-controlled variable resistor device

Abstract

The invention discloses a voltage-controlled variable resistor device which comprises a first switching tube, a voltage dividing module, a voltage-adjustable power supply module, a switching module and a voltage following module, the switching module is electrically connected with the first switching tube, the voltage dividing module, the voltage adjustable power supply module and the voltage following module; the switching module is configured to execute the following steps: enabling the first switching tube, the voltage dividing module and the voltage adjustable power supply module to form a voltage range determining circuit; in the voltage range determination circuit, under the condition that a first switching tube is in a variable resistance region, a voltage output range of a voltage-adjustable power supply module corresponding to the resistance change of the first switching tube is determined; the switching module is further configured to execute the following steps: enabling the first switching tube, the voltage-adjustable power supply module and the voltage following module to form a voltage-controlled resistor circuit; in the voltage-controlled resistor circuit, the voltage-adjustable power supply module outputs voltage within a voltage output range, and the first switching tube is used as a variable resistor in the load circuit.

Description

Technical Field

[0001] The embodiments of the present invention relate to electronic power technology, and in particular to a voltage-controlled variable resistor device. Background Art

[0002] When conducting experiments using a thermostat, the resistance of an NTC resistor is often used to represent temperature. Software scripts are used to control the thermostat, allowing it to change its temperature range in steps. Changes in the thermostat's temperature correspond to changes in the resistance of the NTC resistor. However, sometimes experiments no longer require a thermostat, but instead use a variable resistor, which is then configured to simulate temperature changes along a specific curve.

[0003] Currently, most existing variable resistor devices are manually adjustable or fixed-value, lacking automated curve simulation capabilities and failing to meet the sophisticated demands of modern electronic testing and development. Furthermore, in applications requiring high-precision resistance control, it's difficult to automatically determine the input voltage range for voltage-controlled variable resistors, hindering sufficient control accuracy and flexibility. Summary of the Invention

[0004] The present invention provides a voltage-controlled variable resistor device to achieve the purpose of solving at least one defect in the prior art.

[0005] An embodiment of the present invention provides a voltage-controlled variable resistor device, comprising:

[0006] A first switching tube, a voltage dividing module, a voltage adjustable power supply module, a switching module and a voltage following module;

[0007] The switching module is electrically connected to the first switch tube, the voltage divider module, the voltage adjustable power supply module and the voltage follower module, and is configured to perform:

[0008] The first switch tube, the voltage divider module and the voltage-adjustable power supply module form a voltage range determination circuit;

[0009] In the voltage range determination circuit, when the first switch tube is in the variable resistance region, the voltage output range of the voltage-adjustable power supply module corresponding to the resistance change of the first switch tube is determined;

[0010] The switching module is further configured to execute: enabling the first switch tube, the voltage-adjustable power supply module and the voltage follower module to form a voltage-controlled resistor circuit;

[0011] In the voltage-controlled resistor circuit, the voltage follower module is used to control the resistance change of the first switch tube through the output voltage of the voltage-adjustable power supply module based on the voltage output range.

[0012] Optionally, in the voltage range determination circuit, the voltage-adjustable power supply module is configured to control the voltage of the control terminal of the first switch tube;

[0013] In the voltage-controlled resistor circuit, the voltage follower module is used to control the voltage of the control end of the first switch tube according to the output voltage of the voltage-adjustable power supply module, so as to control the resistance change of the first switch tube.

[0014] Optionally, the voltage dividing module includes a first power supply terminal and a resistor network;

[0015] The first power supply terminal is used to connect to a first power supply, and the first power supply terminal is connected in series with the first switch tube through the resistor network;

[0016] At least one resistor in the variable resistor network is used to form a voltage divider circuit with the first switch tube, and the voltage divider circuit is used to make the voltage difference between the first end and the second end of the first switch tube within a preset voltage range.

[0017] Optionally, the resistor network includes a first switch and a plurality of resistors connected in parallel, wherein each resistor in the plurality of resistors connected in parallel corresponds to a resistance value of a different gear;

[0018] The first power supply end is connected to the resistors arranged in parallel via the first switching switch, and the first switching switch is used to connect a resistor in the resistor network in series with the first switching tube.

[0019] Optionally, the voltage-adjustable power supply module includes a second power supply terminal, a first resistor and a second resistor, and the second resistor is a variable resistor;

[0020] The second power supply terminal is used to connect to the first power supply, and the second power supply terminal is connected in series with the first resistor and the second resistor;

[0021] The second resistor is used to adjust the output voltage of the voltage-adjustable power supply module.

[0022] Optionally, it further includes a first controllable switch;

[0023] The second power supply terminal is connected in series with the first resistor, and the first resistor is connected in series with the second resistor via the first controllable switch;

[0024] The first controllable switch is used to connect or disconnect the first resistor and the second resistor.

[0025] Optionally, the switching module includes a first switching switch, a second switching switch, and a third switching switch;

[0026] The first end, the second end, and the third end of the first switching switch are electrically connected to the first end of the first switching tube, the output end, and the open circuit end of the voltage divider module respectively;

[0027] The first end, the second end, and the third end of the second switch are electrically connected to the second end of the first switch tube, the reference power supply end, and the first end of the voltage follower module respectively;

[0028] The first end, the second end, and the third end of the third switch are electrically connected to the control end of the first switch tube and the second end and the third end of the voltage follower module respectively;

[0029] The output end of the voltage-adjustable power supply module is electrically connected to the second end of the voltage follower module;

[0030] When the first switch, the second switch, and the third switch are closed, they constitute the voltage range determination circuit;

[0031] When the first switch, the second switch, and the third switch are turned off, the voltage-controlled resistor circuit is formed.

[0032] Optionally, it further includes a first relay, a second relay, a third resistor, a fourth resistor, a second controllable switch, and a second switching tube;

[0033] The first switch and the second switch are electrically connected to the contacts of the first relay, and the third switch is electrically connected to the contact of the second relay;

[0034] The second power supply is connected in series with the second switch tube through the coil of the first relay and the coil of the second relay respectively;

[0035] A first power supply is connected in series with the third resistor, the second controllable switch, and the fourth resistor, and a connection point between the second controllable switch and the fourth resistor in series is electrically connected to a control terminal of the second controllable switch;

[0036] The second controllable switch is used to control the on or off of the second switch tube.

[0037] Optionally, the voltage follower module includes a voltage follower and an amplifier;

[0038] The first input terminal of the voltage follower is connected to the second terminal of the first switch tube, and the second input terminal of the voltage follower is connected to the output terminal of the voltage follower;

[0039] The first input end of the amplifier is connected to the output end of the voltage follower and the output end of the voltage-adjustable power supply module, and the second input end of the amplifier is connected to the output end of the amplifier;

[0040] The output end of the amplifier is connected to the control end of the first switch tube.

[0041] Optionally, the output terminal of the voltage follower is connected to the first input terminal of the amplifier through a fifth resistor;

[0042] The output end of the voltage-adjustable power supply module is connected to the first input end of the amplifier through a sixth resistor;

[0043] A seventh resistor and an eighth resistor connected in series are provided at the second input end of the amplifier, wherein the eighth resistor serves as a feedback resistor of the amplifier;

[0044] The fifth resistor has the same resistance value as the sixth resistor, and the seventh resistor has the same resistance value as the eighth resistor.

[0045] Compared with the prior art, the beneficial effects of the present invention are as follows: the present invention proposes a voltage-controlled variable resistor device, which includes a voltage range determination circuit and a voltage-controlled resistor circuit. The voltage range determination circuit and the voltage-controlled resistor circuit are switchable. By using the voltage range determination circuit, the voltage range corresponding to when the voltage-controlled variable resistor enters the specified resistance interval can be accurately determined; by using the voltage-controlled resistor circuit, the first switching tube can be used as a variable resistor in the load circuit to meet the application requirements of different circuits.

[0046] In the voltage-controlled resistor circuit, the voltage at the control terminal of the first switching tube is controlled by a voltage-adjustable power supply module. Based on the voltage follower module, it can ensure that the voltage output to the gate of the first switching tube is the same as the voltage range determined by the voltage range determination circuit, which can effectively define the resistance range of the variable resistor, ensure the accuracy and stability of voltage control, and improve the control precision of the variable resistor resistance. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 is a structural block diagram of a voltage-controlled variable resistor device in an embodiment;

[0048] Figure 2 2 is a schematic structural diagram of a voltage divider module in an embodiment;

[0049] Figure 3 1 is a schematic structural diagram of a voltage-adjustable power supply module in an embodiment;

[0050] Figure 4 is a structural block diagram of a switching module in an embodiment;

[0051] Figure 5 Schematic diagram of the switching module in the embodiment;

[0052] Figure 6 Schematic diagram of the voltage follower module in the embodiment;

[0053] Figure 7 Schematic diagram of the voltage-controlled variable resistor device in the embodiment. Detailed implementation manners

[0054] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It can be understood that the specific embodiments described herein are only used to explain the present invention, rather than limiting the present invention. In addition, it should be noted that, for the sake of description, only the parts related to the present invention rather than all the structures are shown in the drawings.

[0055] Figure 1 It is the structural block diagram of the voltage-controlled variable resistor device in the embodiment. Refer to Figure 1 , the voltage-controlled variable resistor device includes:

[0056] The first switching tube 1, the voltage dividing module 100, the voltage adjustable power supply module 200, the switching module 300, and the voltage follower module 400.

[0057] The switching module 300 is electrically connected to the first switching tube 1, the voltage dividing module 100, the voltage adjustable power supply module 200, and the voltage follower module 400. The switching module 300 is configured to:

[0058] Make the first switching tube 1, the voltage dividing module 100, and the voltage adjustable power supply module 200 form a voltage range determination circuit. Make the first switching tube 1, the voltage adjustable power supply module 200, and the voltage follower module 400 form a voltage-controlled resistor circuit.

[0059] Exemplarily, in the present solution, the type of the first switching tube 1 is not limited, and it can be a MOS tube, a triode, etc. Among them, the MOS tube can be an enhancement-mode MOS tube or a depletion-mode MOS tube. Exemplarily, in the present solution, taking the enhancement-mode MOS tube as an example, when the drain voltage Vds and the gate-source voltage of the MOS tube satisfy Vgs>VTH and Vds<Vgs–VTH, the MOS tube is in the variable resistance region, and the on-resistance Rds of the MOS tube changes with the change of the gate voltage.

[0060] Exemplarily, in the present solution, in the voltage range determination circuit, the voltage dividing module 100 and the voltage adjustable power supply module 200 are used to make the first switching tube 1 be in the variable resistance region.

[0061] For example, in this solution, in the voltage range determination circuit, the output voltage of the voltage divider module 100 is configured to determine Vds, and the voltage adjustable power supply module 200 is configured to determine Vgs. By adjusting the output voltages of the voltage divider module 100 and the voltage adjustable power supply module 200 to be in a suitable range, the MOS tube is placed in the variable resistance zone.

[0062] For example, in this solution, the output voltage of the voltage divider module 100 can be configured to adjust the drain voltage of the first switch tube 1 , thereby adjusting the Vds of the first switch tube 1 .

[0063] Illustratively, in this solution, a voltage-adjustable power supply module 200 may be configured to adjust the gate voltage, source voltage, or source current of the first switch tube 1 , thereby adjusting the Vgs of the first switch tube 1 .

[0064] In this solution, in practical applications, the first switch 1 functions as a variable resistor, setting its resistance within a preset range. Because Vgs is related to Rds, when the Vgs voltage varies along a predetermined curve, the resistance of the first switch 1 can be controlled by voltage to follow the predetermined curve.

[0065] The function of the voltage range determination circuit is to determine the accurate voltage output range of the voltage-adjustable power supply module 200 so that the resistance of the first switch tube 1 can vary within a preset resistance range.

[0066] In this solution, in the voltage range determination circuit, when the first switch tube 1 is in the variable resistance region, the voltage output range of the voltage adjustable power supply module 200 corresponding to the resistance change of the first switch tube 1 is determined.

[0067] For example, in this solution, when the first switch tube 1 is in the variable resistance region, its on-resistance Rds and Vgs can be measured (using a multimeter, semiconductor tester, etc.). Simultaneously, the output voltage of the voltage-adjustable power supply module 200 can be measured.

[0068] Illustratively, in this solution, the output voltage of the voltage-adjustable power module 200 can be adjusted, and the output voltage of the voltage-adjustable power module 200 when the resistance of the first switch tube 1 is in a preset resistance range is recorded as the voltage output range.

[0069] For example, determine the minimum resistance Rmin and maximum resistance Rmax required for the first switching transistor 1. Adjust the output voltage of the adjustable voltage power supply module 200 so that the resistance of the first switching transistor 1 reaches Rmin, and record the output voltage of the adjustable voltage power supply module 200 at this point as V11. Adjust the output voltage of the adjustable voltage power supply module 200 so that the resistance of the first switching transistor 1 reaches Rmax, and record the output voltage of the adjustable voltage power supply module 200 at this point as V12. V11 and V12 are the limits of the output voltage range of the adjustable voltage power supply module 200.

[0070] In the voltage-controlled resistor circuit, the voltage-adjustable power supply module 200 outputs a voltage within a voltage output range, and the first switch tube 1 is used as a variable resistor in the load circuit.

[0071] In this solution, in a voltage-controlled resistor circuit, the first switch 1 is connected to a load circuit requiring a variable resistor via terminals RES_POS and RES_NEG. The voltage follower module 400 controls the resistance of the first switch 1 using the output voltage of the adjustable voltage power supply module 200, based on the voltage output range.

[0072] In this solution, the voltage follower module 400 primarily functions to place the connected end of the first switching transistor 1 in a high-impedance state, thereby preventing the first switching transistor 1 from affecting the load circuit when used in the load circuit. The voltage follower module 400 also ensures that the Vgs of the first switching transistor 1 is consistent with the output voltage of the adjustable voltage power supply module 200. This ensures that, after determining the output voltage range of the adjustable voltage power supply module 200, the first switching transistor 1 varies within a preset resistance range.

[0073] For example, in this solution, the voltage follower module 400 may be designed based on an amplifier with a relatively high input impedance (eg, greater than 1 MΩ), so as to have high-impedance input and voltage following functions.

[0074] For example, in this solution, the voltage follower module 400 may be configured to copy the output voltage of the voltage-adjustable power supply module 200 to the gate or source of the first switch tube 1 , thereby controlling the Vgs of the first switch tube 1 .

[0075] Exemplarily, in this solution, the switching module 300 may include several analog switches, which are arranged at designated nodes corresponding to the voltage range determination circuit and the voltage-controlled resistor circuit. The switching of the voltage range determination circuit and the voltage-controlled resistor circuit is achieved by controlling the on-off of the designated analog switches.

[0076] For example, in this solution, the voltage divider module 100 and the voltage adjustable power supply module 200 can be designed to adjust the voltage manually or automatically, and both can be designed based on an adjustable voltage regulator, or based on a reference voltage source and a voltage regulating resistor network.

[0077] This embodiment proposes a voltage-controlled variable resistor device, which includes a voltage range determination circuit and a voltage-controlled resistor circuit. The voltage range determination circuit and the voltage-controlled resistor circuit are switchable. The voltage range determination circuit can be used to accurately determine the voltage range corresponding to when the voltage-controlled variable resistor enters a specified resistance range; the voltage-controlled resistor circuit can be used to enable the first switching tube to serve as a variable resistor in the load circuit to meet the application requirements of different circuits.

[0078] The device adopts modular design, with each module having clear division of labor and working in coordination. When realizing the variable resistance function, it reduces unnecessary components and complex circuit structures, reduces hardware costs and design complexity, and also facilitates subsequent maintenance and upgrades.

[0079] Based on any of the foregoing solutions, in one possible implementation, in the voltage range determination circuit, the voltage-adjustable power supply module is configured to control the voltage of the control terminal of the first switch tube.

[0080] For example, in this solution, the output terminal of the voltage-adjustable power supply module can be connected to the control terminal of the first switching tube via a voltage divider resistor or directly to directly adjust the voltage at the control terminal of the first switching tube. This approach can reduce the complexity of the voltage range determination circuit.

[0081] Illustratively, in this solution, in the voltage-controlled resistor circuit, the voltage follower module is used to control the voltage of the control terminal of the first switch tube according to the output voltage of the voltage-adjustable power supply module to control the resistance change of the first switch tube.

[0082] In this solution, the voltage at the control terminal of the first switching tube is controlled by a voltage-adjustable power supply module, and a voltage-following module is correspondingly provided to copy the output voltage of the voltage-adjustable power supply module to the control terminal of the first switching tube. Based on this, it can be accurately ensured that the voltage output to the control terminal of the first switching tube is the same as the voltage range determined by the voltage range determination circuit, thereby effectively defining the resistance range of the variable resistor, ensuring the accuracy and stability of the voltage control, and improving the control precision of the variable resistor resistance.

[0083] Based on any of the foregoing solutions, in one possible implementation, the voltage divider module includes a first power supply terminal and a resistor network.

[0084] The first power supply terminal is used to access the first power supply, and the first power supply terminal is connected in series with the first switch tube through a resistor network.

[0085] At least one resistor in the variable resistor network is used to form a voltage divider circuit with the first switch tube, and the voltage divider circuit is used to make the voltage difference between the first end and the second end of the first switch tube within a preset voltage range.

[0086] Illustratively, in this solution, the power supply may adopt a reference voltage source (eg, 2.5V to 10V) to provide a stable voltage reference for the resistor network and the first switch tube.

[0087] The resistor network may include a fixed resistor and an adjustable resistor. The resistor network is connected in series with the first switch tube to form a voltage divider structure. By adjusting the resistance value of the resistor network, the Vds of the first switch tube can be accurately controlled within a preset range.

[0088] For example, when the on-resistance Rds of the first switch tube is determined, Vds can be determined by the following formula:

[0089]

[0090] Where Vref represents the output voltage of the first power supply, and Rr represents the resistance of the resistor network. The resistance of Rr can be determined based on the condition that the first switch is in the variable resistance range. If Vds needs to be obtained through measurement, the resistance of Rr can also be determined based on the range of the measuring instrument.

[0091] Figure 2 This is a schematic diagram of the voltage divider module structure in the embodiment, refer to Figure 2 In one embodiment, the resistor network includes a first switch S1 and a plurality of resistors (R3 to R7) connected in parallel.

[0092] The first power supply terminal VREF_2V5 is connected to a resistor arranged in parallel via a first switch S1. The first switch is used to connect a resistor in a resistor network in series with the first switch tube.

[0093] In this solution, the first power supply can be designed based on ADR441-EP, and the first power supply is designed to output a 2.5V voltage. Accordingly, the first power supply terminal VREF_2V5 provides a stable reference voltage (2.5V), which is connected to the resistor network composed of the first switching switch S1 and parallel resistors (R3~R7).

[0094] The first switch S1 acts as a selector. It can select the connection between VREF_2V5 and one of the resistors R3-R7. When S1 is connected to a resistor (for example, R3), the circuit is equivalent to only R3 connected in series with the first switch (the other unselected resistors do not participate in the series circuit in this state).

[0095] According to the principle of series voltage division, the voltage across each component in a series circuit is proportional to its resistance. When the first switch is connected in series with a selected resistor (such as R3), the voltage of VREF_2V5 is distributed between the first switch and the resistor.

[0096] Since different resistors have different values, when S1 is switched to select different resistors, the voltages across the first switch tube will be different. In this way, the voltage difference across the first switch tube can be changed to be within a reasonable voltage range.

[0097] For example, in this embodiment, each of the plurality of resistors connected in parallel corresponds to a different resistance value. The different resistance values ​​may be a plurality of resistance values ​​having a geometric relationship. The number of resistors can be set according to actual needs and is not limited here. For example, six resistors may be provided, with resistance values ​​of 100Ω, 1KΩ, 10KΩ, 100KΩ, 1MΩ, etc.

[0098] In this solution, each resistor corresponds to a gear. Switching different resistors can change the voltage division ratio, thereby adjusting the Vds of the switch tube. The gear resistance value can be designed according to the variable resistance zone characteristics of the first switch tube. The gear resistance value and Rds can be at the same order of magnitude, thereby ensuring the voltage division effect.

[0099] Figure 3 This is a schematic diagram of the voltage adjustable power supply module structure in the embodiment, refer to Figure 3 Based on any of the aforementioned solutions, in one possible implementation scheme, the voltage-adjustable power supply module includes a third power supply terminal Hook6, which is used to connect to a programmable power supply; the programmable power supply is used to adjust the output voltage of the voltage-adjustable power supply module.

[0100] In this solution, the third power supply terminal Hook6 serves as an access point for an external programmable power supply. Its output voltage is directly used as the output of the voltage-adjustable power supply module to control the first switching transistor Vgs. By generating a control signal through a microcontroller or FPGA and adjusting the output voltage of the programmable power supply, precise control of Vgd can be achieved.

[0101] In this solution, by adopting a programmable power supply, the voltage-adjustable power supply module realizes digital, high-precision, and programmable voltage control, significantly improving the performance and application flexibility of the voltage-controlled variable resistor device.

[0102] refer to Figure 3 Based on any of the above solutions, in one possible implementation, the voltage-adjustable power supply module includes a second power supply terminal VREF_2V5, a first resistor R8, and a second resistor RP1, and the second resistor RP1 is a variable resistor.

[0103] The second power supply terminal VREF_2V5 is used to access the first power supply. The second power supply terminal VREF_2V5 is connected in series with the first resistor R8 and the second resistor RP1. The second resistor RP1 is used to adjust the output voltage of the voltage-adjustable power supply module.

[0104] The second power supply terminal VREF_2V5 is connected to the first power supply to provide a stable voltage input basis for the entire module.

[0105] In this solution, the first power supply is configured to output a 2.5V reference voltage. Changing the resistance of variable resistor RP1 changes the voltage across RP1 (the output voltage of the adjustable voltage power supply module) accordingly. By manually or otherwise adjusting the resistance of RP1, the voltage output by the adjustable voltage power supply module to the gate of the first switching transistor can be adjusted, thereby controlling the operating state of the first switching transistor.

[0106] refer to Figure 3 Based on any of the aforementioned solutions, in one possible implementation, the voltage-adjustable power supply module further includes a first controllable switch (S2, S3).

[0107] The second power supply terminal VREF_2V5 is connected in series with the first resistor R8, and the first resistor R8 is connected in series with the second resistor RP1 via a first controllable switch. The first controllable switch is used to connect or disconnect the first resistor and the second resistor.

[0108] In this solution, the voltage-adjustable power supply module can be connected to the programmable power supply through the third power supply terminal Hook6 and to the reference voltage source through the second power supply terminal VREF_2V5. The voltage-adjustable power supply module has two ways to control the gate voltage of the first switching tube.

[0109] In this solution, when a programmable power supply is used to control the output voltage of the voltage-adjustable power supply module, the first controllable switch is disconnected, and the programmable power supply controls the gate voltage of the first switching tube according to a predetermined voltage curve; when the first controllable switch is closed, the resistance value of RP1 is adjusted to control the gate voltage of the first switching tube.

[0110] Figure 4 This is a structural diagram of the switching module in the embodiment, refer to Figure 4 Based on any of the aforementioned solutions, in one possible implementation, the switching module includes a first switching switch 301 , a second switching switch 302 , and a third switching switch 303 .

[0111] The first end, the second end, and the third end of the first switch 301 are electrically connected to the first end of the first switch tube 1 , the output end of the voltage divider module 100 , and the open circuit end HK, respectively.

[0112] The first end, the second end, and the third end of the second switch 302 are electrically connected to the second end of the first switch tube 1 , the reference power supply end, and the first end of the voltage follower module 400 , respectively.

[0113] The first end, the second end, and the third end of the third switch 303 are electrically connected to the control end of the first switch tube 1 and the second end and the third end of the voltage follower module 400 respectively.

[0114] The output end of the voltage-adjustable power supply module 200 is electrically connected to the second end of the voltage follower module 400 .

[0115] In this solution, when the first switch 301, the second switch 302, and the third switch 303 are closed, a voltage range determination circuit is formed. When the first switch 301, the second switch 302, and the third switch 303 are open, a voltage-controlled resistor circuit is formed.

[0116] In this solution, when the first switch 301, the second switch 302, and the third switch 303 are closed, the first end of the first switch tube 1 is connected to the output end of the voltage divider module 100, the second end of the first switch tube 1 is connected to the reference power supply end, and the control end of the first switch tube 1 is connected to the second end of the voltage follower module 400, thereby forming a voltage range determination circuit.

[0117] When the first switch 301, the second switch 302, and the third switch 303 are disconnected, the first end of the first switch tube 1 is connected to the open end, the second end of the first switch tube 1 is connected to the first end of the voltage follower module 400, and the control end of the first switch tube 1 is connected to the third end of the voltage follower module 400, thereby forming a voltage-controlled resistor circuit.

[0118] In this solution, the first switch 301 , the second switch 302 and the third switch 303 can be mechanical switches or program-controlled switches as needed.

[0119] Figure 5 This is a schematic diagram of the switching module structure in the embodiment, refer to Figure 5 On the basis of the above solution, as an implementable embodiment, the switching module further includes a first relay Re1, a second relay Re2, a third resistor R13, a fourth resistor R14, a second controllable switch S4, and a second switch tube Q2.

[0120] The first switch 301 and the second switch 302 are electrically connected to the contact of the first relay Re1 , and the third switch 303 is electrically connected to the contact of the second relay Re2 .

[0121] The second power supply is connected in series with the second switch tube Q2 through the coil of the first relay Re1 and the coil of the second relay Re2.

[0122] The first power supply is connected in series with the third resistor R13, the second controllable switch S4, and the fourth resistor R14. The connection point between the second controllable switch S4 and the fourth resistor R14 is electrically connected to the control end of the second controllable switch R14.

[0123] In this solution, the first power supply adopts a 2.5V reference power supply, and the second power supply adopts a 5V reference power supply.

[0124] In this solution, the second controllable switch S4 may be a mechanical switch, and the second controllable switch S4 is used to control the on or off of the second switch tube Q2.

[0125] In this solution, the second controllable switch S4 can be manually controlled to be turned on or off. In this circuit, the second controllable switch S4 is used to control the second switching tube Q2 to be turned on or off.

[0126] The on / off state of the second switching transistor Q2 controls whether the coils of relays Re1 and Re2 are energized. When Q2 is on, the relay coils are energized, and the contacts operate, closing the first, second, and third switches 301, 302, and 303. When Q2 is off, the relay coils are de-energized, the contacts operate, and the first, second, and third switches 301, 302, and 303 are opened.

[0127] In this solution, diodes D2 and D3 provide freewheeling protection for the first relay Re1 and the second relay Re2, respectively. When the relay coil is de-energized, the diodes provide a discharge path to prevent the reverse electromotive force from damaging other components in the circuit.

[0128] Figure 6 This is a schematic diagram of the voltage follower module structure in the embodiment, refer to Figure 6 Based on any of the aforementioned solutions, in one possible implementation, the voltage follower module includes a voltage follower U3 and an amplifier U4.

[0129] The first input terminal Hook4 of the voltage follower U3 is connected to the second terminal of the first switch tube 1 , and the second input terminal of the voltage follower U3 is connected to the output terminal Hook5 of the voltage follower U3 .

[0130] The first input terminal of the amplifier U4 is connected to the output terminal Hook5 of the voltage follower U3 and the output terminal of the voltage-adjustable power supply module 200. The second input terminal of the amplifier U4 is connected to the output terminal Hook7 of the amplifier U4. The output terminal Hook7 of the amplifier U4 is connected to the control terminal of the first switch tube 1.

[0131] refer to Figure 6Specifically, in this solution, the output terminal Hook5 of the voltage follower U3 is connected to the first input terminal of the amplifier U4 through the fifth resistor R9, and the output terminal of the voltage adjustable power supply module 200 is connected to the first input terminal of the amplifier U4 through the sixth resistor R10.

[0132] A seventh resistor R12 and an eighth resistor R11 connected in series are provided at the second input terminal of the amplifier U4 , wherein the eighth resistor R11 serves as a feedback resistor of the amplifier U4 .

[0133] In this solution, the voltage output from the first input terminal Hook4 of the voltage follower U3 is set to Vcircuit, the voltage output from the output terminal Hook5 of the voltage follower U3 is set to Vfollow, the voltage output from the output terminal Hook7 of the amplifier U4 is set to Vout_sum, the voltage output from the adjustable voltage power supply module 200 is set to Vsupply, the voltage output from the first input terminal of the amplifier U4 is set to V1, and the voltage output from the second input terminal of the amplifier U4 is set to V2.

[0134] In this solution, Vcircuit=Vfollow, and the amplifier U4 as a whole acts as an adding amplifier. Due to the virtual disconnection, the currents flowing through R9 and R10 are equal, and the currents flowing through R11 and R12 are equal, so we can obtain: (Vfollow-V1) / R9=(V2-Vsupply) / R10; (Vout_sum-V2) / R11=V2 / R12.

[0135] Due to the virtual short, V+=V-. If R9=R10 and R11=R12, then Vout_sum=Vfollow+Vsupply. Since Vgs=Vout_sum-Vcircuit, Vgs=Vsupply.

[0136] Based on the above design, the voltage follower module 400 can make the Vgd of the first switch tube 1 the same as the output voltage of the voltage-adjustable power supply module 200 .

[0137] Figure 7 is a schematic diagram of the structure of the voltage-controlled variable resistor device in the embodiment, refer to Figures 1 to 7 Based on any of the aforementioned solutions, in one possible implementation, the device includes a first switching tube, a voltage divider module, a voltage adjustable power supply module, a voltage follower module and a switching module.

[0138] The first switch tube is an enhancement mode MOS tube Q1.

[0139] The voltage dividing module includes a first switch S1 and a plurality of resistors (R3-R7) connected in parallel.

[0140] The voltage-adjustable power supply module includes a third power supply terminal Hook6 for connecting to a programmable power supply. The voltage-adjustable power supply module also includes a power supply terminal VREF_2V5, a first resistor R8, a first controllable switch (including S2 and S3), and a second resistor RP1, which is a variable resistor.

[0141] The power supply terminal VREF_2V5 is connected in series with the first resistor R8, and the first resistor R8 is connected in series with the second resistor RP1 via a first controllable switch.

[0142] The third power supply terminal Hook6 is connected to the output terminal Vsupply of the voltage-adjustable power supply module, and the connection point between S2 and S3 is connected to the output terminal Vsupply.

[0143] The voltage follower module includes a voltage follower U3 and an amplifier U4. The amplifier U4 is configured with peripheral components R9 to R12.

[0144] The switching module includes a first relay Re1, a second relay Re2, a third resistor R13, a fourth resistor R14, a second controllable switch S4, and a second switch tube Q2;

[0145] The 5V power supply is connected in series with the second switch tube Q2 through the coil of the first relay Re1 and the coil of the second relay Re2 respectively.

[0146] The 2.5V power supply is connected in series with the third resistor R13, the second controllable switch S4, and the fourth resistor R14. The connection point of the second controllable switch S4 and the fourth resistor R14 in series is electrically connected to the control end of the second controllable switch R14.

[0147] The first relay Re1 is configured with a first relay switch RLY_SW_1 and a second relay switch RLY_SW_2 , and the second relay is configured with a third relay switch RLY_SW_3 .

[0148] The first end, the second end, and the third end of the first relay switch RLY_SW_1 are electrically connected to the first end of Q1 , the output end of the voltage divider module, and the open circuit end, respectively.

[0149] The first end, the second end, and the third end of the second relay switch RLY_SW_2 are electrically connected to the second end of Q1 , the reference power supply end, and the first end of the voltage follower U3 , respectively.

[0150] A first end, a second end, and a third end of the third relay switch RLY_SW_3 are electrically connected to the control end of Q1 and the second end and the third end of the amplifier U4 respectively.

[0151] For example, in this solution, the 2.5V power supply can be based on an LDO design, and the LDO chip model can be ADR441-EP. The power supply for voltage follower U3 and amplifier U4 uses a 10V power supply, which can be based on a DCDC design, and the DCDC chip model can be TPS61040.

[0152] For example, in this solution, the voltage follower U3 may be of model ADA4530-1, and the amplifier U4 may be of model ADA4530-1.

[0153] In this solution, the Rds range required by Q1 is set to 50K~300K. The device can be used in the following ways:

[0154] The first switch S1 is set to an appropriate resistance value to form a voltage divider with Q1. The appropriate resistance value is specifically selected from resistor R6 (100K).

[0155] The second controllable switch S4 is controlled to open. At this time, the drain and source of Q1 are switched to the pull-up resistor R6 and ground through the first relay switch RLY_SW_1 and the second relay switch RLY_SW_2 respectively. Q1 is directly powered by Vsupply (ie, without passing through the amplifier U4), and Vgs=Vsupply.

[0156] An external programmable power supply is connected between the third power supply terminals Hook6 and Hook9 to control the first controllable switch to be disconnected, and the voltage range and curve form of the programmable power supply are controlled in a software script manner.

[0157] When Rds is 50K and 300K, the voltage corresponding to Q1's Vds is calculated as follows: Rds is 50K, Vds / 2.5=50 / (50+100), Vds=0.833V; Rds is 300K, Vds / 2.5=300 / (300+100), Vds=1.875V.

[0158] Use digital multimeter DMM1 to measure the voltage between Hook1 and Hook9, that is, the measured value of Vds of Q1. Use digital multimeter DMM2 to measure the voltage between Hook8 and Hook9, that is, the measured value of Vgs of Q1.

[0159] Adjust the voltage of the programmable power supply so that the reading of DMM1 reaches 0.833V, record the value of DMM2 at this time, and record it as V11. Adjust the voltage of the programmable power supply so that the reading of DMM1 reaches 1.875V, record the value of DMM2 at this time, and record it as V12.

[0160] When Q1 is used as a voltage-controlled variable resistor, the second controllable switch S4 is disconnected. At this point, Q1's drain and source are switched to the open-drain output and the positive input of voltage follower U3, respectively, via the first relay switch RLY_SW_1 and the third relay switch RLY_SW_3. Q1 is powered by amplifier U4, with Vgs = Vsupply.

[0161] Hook2 and Hook3 corresponding to Q1 must be connected to the positive pole RES_POS and negative pole RES_NEG of the load circuit.

[0162] The voltage range and curve form of the programmable power supply are controlled by software script so that the Vgs of Q1 changes along a predetermined curve within the voltage range corresponding to V11 and V12, thereby making Q1 a 50K~300K voltage-controlled variable resistor.

[0163] Note that the above are only preferred embodiments of the present invention and the technical principles employed. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and that various obvious changes, readjustments, and substitutions can be made by those skilled in the art without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in detail through the above embodiments, the present invention is not limited to the above embodiments and may include many other equivalent embodiments without departing from the concept of the present invention. The scope of the present invention is determined by the scope of the appended claims.

Claims

1. A voltage-controlled variable resistor device, characterized in that: include: A first switching tube, a voltage dividing module, a voltage adjustable power supply module, a switching module and a voltage following module; The switching module is electrically connected to the first switch tube, the voltage dividing module, the voltage adjustable power supply module and the voltage following module; The switching module is configured to execute: enabling the first switch tube, the voltage divider module and the voltage-adjustable power supply module to form a voltage range determination circuit; In the voltage range determination circuit, when the first switch tube is in the variable resistance region, the voltage output range of the voltage-adjustable power supply module corresponding to the resistance change of the first switch tube is determined; The switching module is further configured to execute: enabling the first switch tube, the voltage-adjustable power supply module and the voltage follower module to form a voltage-controlled resistor circuit; In the voltage-controlled resistor circuit, the voltage follower module is used to control the resistance change of the first switch tube through the output voltage of the voltage-adjustable power supply module based on the voltage output range.

2. The voltage-controlled variable resistor device according to claim 1, wherein In the voltage range determination circuit, the voltage-adjustable power supply module is configured to control the voltage of the control terminal of the first switch tube; In the voltage-controlled resistor circuit, the voltage follower module is used to control the voltage of the control end of the first switch tube according to the output voltage of the voltage-adjustable power supply module, so as to control the resistance change of the first switch tube.

3. The voltage-controlled variable resistor device according to claim 1, wherein The voltage dividing module includes a first power supply terminal and a resistor network; The first power supply terminal is used to connect to a first power supply, and the first power supply terminal is connected in series with the first switch tube through the resistor network; At least one resistor in the variable resistor network is used to form a voltage divider circuit with the first switch tube, and the voltage divider circuit is used to make the voltage difference between the first end and the second end of the first switch tube within a preset voltage range.

4. The voltage-controlled variable resistor device according to claim 3, wherein The resistor network includes a first switch and a plurality of resistors connected in parallel, wherein each resistor in the plurality of resistors connected in parallel corresponds to a resistance value of a different gear; The first power supply end is connected to the resistors arranged in parallel via the first switching switch, and the first switching switch is used to connect a resistor in the resistor network in series with the first switching tube.

5. The voltage-controlled variable resistor device according to claim 1, wherein The voltage-adjustable power supply module includes a second power supply terminal, a first resistor and a second resistor, wherein the second resistor is a variable resistor; The second power supply terminal is used to connect to the first power supply, and the second power supply terminal is connected in series with the first resistor and the second resistor; The second resistor is used to adjust the output voltage of the voltage-adjustable power supply module.

6. The voltage-controlled variable resistor device according to claim 5, wherein: Also included is a first controllable switch; The second power supply terminal is connected in series with the first resistor, and the first resistor is connected in series with the second resistor via the first controllable switch; The first controllable switch is used to connect or disconnect the first resistor and the second resistor.

7. The voltage-controlled variable resistor device according to claim 1, wherein The switching module includes a first switching switch, a second switching switch, and a third switching switch; The first end, the second end, and the third end of the first switching switch are electrically connected to the first end of the first switching tube, the output end, and the open circuit end of the voltage divider module respectively; The first end, the second end, and the third end of the second switch are electrically connected to the second end of the first switch tube, the reference power supply end, and the first end of the voltage follower module respectively; The first end, the second end, and the third end of the third switch are electrically connected to the control end of the first switch tube and the second end and the third end of the voltage follower module respectively; The output end of the voltage-adjustable power supply module is electrically connected to the second end of the voltage follower module; When the first switch, the second switch, and the third switch are closed, they constitute the voltage range determination circuit; When the first switch, the second switch, and the third switch are turned off, the voltage-controlled resistor circuit is formed.

8. The voltage-controlled variable resistor device according to claim 7, wherein: It also includes a first relay, a second relay, a third resistor, a fourth resistor, a second controllable switch, and a second switching tube; The first switch and the second switch are electrically connected to the contacts of the first relay, and the third switch is electrically connected to the contact of the second relay; The second power supply is connected in series with the second switch tube through the coil of the first relay and the coil of the second relay respectively; A first power supply is connected in series with the third resistor, the second controllable switch, and the fourth resistor, and a connection point between the second controllable switch and the fourth resistor in series is electrically connected to a control terminal of the second controllable switch; The second controllable switch is used to control the on or off of the second switch tube.

9. The voltage-controlled variable resistor device according to claim 1, wherein The voltage follower module includes a voltage follower and an amplifier; The first input terminal of the voltage follower is connected to the second terminal of the first switch tube, and the second input terminal of the voltage follower is connected to the output terminal of the voltage follower; The first input end of the amplifier is connected to the output end of the voltage follower and the output end of the voltage-adjustable power supply module, and the second input end of the amplifier is connected to the output end of the amplifier; The output end of the amplifier is connected to the control end of the first switch tube.

10. The voltage-controlled variable resistor device according to claim 9, wherein: The output terminal of the voltage follower is connected to the first input terminal of the amplifier through a fifth resistor; The output end of the voltage-adjustable power supply module is connected to the first input end of the amplifier through a sixth resistor; A seventh resistor and an eighth resistor connected in series are provided at the second input end of the amplifier, wherein the eighth resistor serves as a feedback resistor of the amplifier; The fifth resistor has the same resistance value as the sixth resistor, and the seventh resistor has the same resistance value as the eighth resistor.

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