阅读说明：本技术 一种阻值可变的负电阻电路 (Variable negative resistance circuit of resistance ) 是由 李颖弢 霍显杰 田力学 李永刚 于 2020-12-30 设计创作，主要内容包括：本发明公开了一种阻值可变的负电阻电路,包括VCVS、CVCS和若干电阻,整体可等效为一个负电阻,并且通过改变VCVS、CCCS的增益可以改变阻值。该电路具有电压工作范围宽、阻值变化范围广等优势,具有以下优点：a、负电阻阻值的可调范围宽,范围可从0到-∞,需要调节负电阻阻值时,首先调节α大小即可；b、负电阻阻值调节灵活,当所需α较大时,可以调节R2适当改变灵敏度,即可使用相对较小的α值进行实现；c、负电阻阻值的精度较高,在α确定的条件下,通过调节β,可使负电阻阻值缓慢地到达所需精度；d、无工作电压的限制,相较于运算放大器构建的电路,本电路可在任意工作电压下运行,无运算放大器必须工作在线性电压区的限制。(The invention discloses a resistance-variable negative resistance circuit, which comprises VCVS, CVCS and a plurality of resistors, wherein the whole circuit can be equivalent to a negative resistor, and the resistance can be changed by changing the gains of the VCVS and the CCCS. The circuit has the advantages of wide voltage working range, wide resistance value change range and the like, and has the following advantages: a. the adjustable range of the resistance value of the negative resistor is wide, the range can be from 0 to-infinity, and when the resistance value of the negative resistor needs to be adjusted, the alpha size is adjusted firstly; b. the negative resistance value is flexibly adjusted, when the required alpha is larger, R2 can be adjusted to properly change the sensitivity, namely the adjustment can be realized by using a relatively smaller alpha value; c. the precision of the resistance value of the negative resistor is high, and the resistance value of the negative resistor can slowly reach the required precision by adjusting beta under the condition that alpha is determined; d. compared with a circuit constructed by an operational amplifier, the circuit can operate under any operating voltage, and the operational amplifier is not limited by the linear voltage region.)

1. A negative resistance circuit with variable resistance is characterized by comprising the following components: the circuit comprises a current controlled current source CCCS, a voltage controlled voltage source VCVS, a shunt resistor R1 and a sensitivity adjusting resistor R2, wherein the circuit comprises a 1 st pin, a 2 nd pin and a 3 rd pin, the shunt resistor R1 is connected between the 1 st pin and the 3 rd pin, the 1 st pin is connected with a high potential point, and the 3 rd pin is connected with a low potential point; a current control current source CCCS is connected between the 1 st pin and the 2 nd pin, and the current I direction of the current control current source CCCS is from the 1 st pin to the 2 nd pin; the 1 st pin and the 2 nd pin are connected in series with a variable resistor R2 as a sensitivity adjusting resistor, and the variable resistor R2 is connected in parallel with a current control current source CCCS; the 2 nd pin and the 3 rd pin are connected with a voltage controlled voltage source VCVS, wherein the 2 nd pin is a low potential point of the voltage controlled voltage source VCVS, the 3 rd pin is a high potential point of the voltage controlled voltage source VCVS, and the control voltage of the voltage controlled voltage source VCVS is the potential difference between the 1 st pin and the 3 rd pin; the 1 st pin and the 3 rd pin are connected with an external circuit, the 1 st pin is connected with a high potential, and the 3 rd pin is connected with a low potential point.

2. The variable-resistance negative resistance circuit according to claim 1, wherein: the control current of the current-controlled current source CCCS is the current I flowing into the 1 st pin high potential point from the external port, the branch current of the current-controlled current source CCCS is the current output by amplifying the control current by alpha times, namely the current I of the current-controlled current source CCCS is alpha I, alpha is the gain of the current-controlled current source CCCS, and the size of I can be controlled.

3. A variable-resistance negative resistance circuit according to claim 1 or 2, wherein: the voltage of the voltage control voltage source VCVS port is control voltage, and the voltage of the branch circuit where the voltage control voltage source VCVS is located is the voltage amplified by beta times of the control voltage.

4. The variable-resistance negative resistance circuit according to claim 3, wherein the resistor is a variable-resistance negative resistor obtained according to kirchhoff's law and thevenin's theorem:

the formula is combined to obtain:

(α is the gain of the current-controlled current source and β is the gain of the voltage-controlled voltage source).

5. The variable-resistance negative resistance circuit according to claim 4, wherein: when in useIt can be represented as a negative resistance; when in useIt may exhibit a positive resistance.

Technical Field

The invention relates to the field of circuit design, in particular to a resistance variable negative resistance circuit with negative resistance characteristics, which can be used in the fields of electronic information engineering, control engineering, circuit design and the like.

Background

The classical circuit theory provides a negative resistance construction method based on an operational amplifier, the method can equivalently realize the negative resistance, but the method must work in a linear voltage working area of the operational amplifier, if the working voltage is not in the linear voltage working area, the working voltage is regarded as a common resistor with determined resistance value, and therefore certain limitation is brought to the use of the negative resistance. The classical negative resistance circuit constructed based on the operational amplifier is limited by the output current of the operational amplifier, so that the adjustment range of the resistance value of the negative resistance circuit is limited to a certain extent. Therefore, a method for constructing a negative resistor with a wide range of resistance values is needed. At present, negative resistance constructed based on organic semiconductor materials appears, but the negative resistance has higher requirements on the selection of processes and materials during manufacturing and has higher manufacturing cost. Aiming at the defects of the negative resistance circuit based on the operational amplifier, the negative resistance circuit with unlimited working voltage and randomly variable negative resistance value needs to be designed.

Disclosure of Invention

The invention provides a negative resistance circuit with variable resistance value aiming at the defects in the prior art, which expands the resistance value range and the working voltage range of the negative resistance value, is constructed by using some existing elements, is convenient to reduce the volume and can be integrated in the circuit.

In order to achieve the purpose, the invention adopts the following technical scheme.

A negative resistance circuit with variable resistance is as follows: the circuit comprises a current controlled current source CCCS, a voltage controlled voltage source VCVS, a shunt resistor R1 and a sensitivity adjusting resistor R2, wherein the circuit comprises a 1 st pin, a 2 nd pin and a 3 rd pin, the shunt resistor R1 is connected between the 1 st pin and the 3 rd pin, the 1 st pin is connected with a high potential point, and the 3 rd pin is connected with a low potential point; a current control current source CCCS is connected between the 1 st pin and the 2 nd pin, and the current I direction of the current control current source CCCS is from the 1 st pin to the 2 nd pin; the 1 st pin and the 2 nd pin are connected in series with a variable resistor R2 as a sensitivity adjusting resistor, and the variable resistor R2 is connected in parallel with a current control current source CCCS; the 2 nd pin and the 3 rd pin are connected with a voltage controlled voltage source VCVS, wherein the 2 nd pin is a low potential point of the voltage controlled voltage source VCVS, the 3 rd pin is a high potential point of the voltage controlled voltage source VCVS, and the control voltage of the voltage controlled voltage source VCVS is the potential difference between the 1 st pin and the 3 rd pin; the 1 st pin and the 3 rd pin are connected with an external circuit, the 1 st pin is connected with a high potential, and the 3 rd pin is connected with a low potential point.

The control current of the current-controlled current source CCCS is the current I flowing into the 1 st pin high potential point from the external port, the branch current of the current-controlled current source CCCS is the current output by amplifying the control current by alpha times, namely the current I of the current-controlled current source CCCS is alpha I, alpha is the gain of the current-controlled current source CCCS, and the size of I can be controlled.

The voltage of the voltage control voltage source VCVS port is control voltage, and the voltage of the branch circuit where the voltage control voltage source VCVS is located is the voltage amplified by beta times of the control voltage.

The resistance is a negative resistance with variable resistance value, and can be obtained according to kirchhoff's law and thevenin's theorem:

the formula is combined to obtain:

(α is the gain of the current-controlled current source and β is the gain of the voltage-controlled voltage source)

When in useIt can be represented as a negative resistance; when in useIt may exhibit a positive resistance.

The invention comprises VCVS, CVCS and several resistors, the whole can be equivalent to a negative resistor when seen from the circuit input end, and the resistance value can be changed by changing the gains of VCVS and CCCS. The circuit has the advantages of wide voltage working range, wide resistance value change range and the like, and can enable the negative resistance to be used in more fields. It has the following advantages: a. the adjustable range of the resistance value of the negative resistor is wide, the range can be from 0 to-infinity, and when the resistance value of the negative resistor needs to be adjusted, the alpha size is adjusted firstly; b. the negative resistance value is flexibly adjusted, when the required alpha is larger, R2 can be adjusted to properly change the sensitivity, namely the adjustment can be realized by using a relatively smaller alpha value; c. the precision of the resistance value of the negative resistor is high, and the resistance value of the negative resistor can slowly reach the required precision by adjusting beta under the condition that alpha is determined; d. compared with a circuit constructed by an operational amplifier, the circuit can operate under any operating voltage, and the operational amplifier is not limited by the linear voltage region.

Drawings

FIG. 1 is a schematic diagram of the circuit structure of the present invention;

FIG. 2 is a flow chart of the steps of resistance adjustment according to the present invention.

Detailed Description

The principles and features of this invention are described below in conjunction with the following drawings, which are set forth by way of illustration only and are not intended to limit the scope of the invention.

Other advantages and capabilities of the present invention will be readily apparent to those skilled in the art from the present disclosure by describing the embodiments of the present invention with specific embodiments thereof in conjunction with the accompanying drawings. The invention is capable of other and different embodiments and its several details are capable of modification in various other respects, all without departing from the spirit and scope of the present invention.

As shown in fig. 1, a negative resistor with a variable resistance has the following overall circuit: the circuit comprises a current controlled current source CCCS, a voltage controlled voltage source VCVS, a shunt resistor R1 and a sensitivity adjusting resistor R2, wherein the circuit comprises a 1 st pin, a 2 nd pin and a 3 rd pin, the shunt resistor R1 is connected between the 1 st pin and the 3 rd pin, the 1 st pin is connected with a high potential point, and the 3 rd pin is connected with a low potential point; a current control current source CCCS is connected between the 1 st pin and the 2 nd pin, the formula of the current control current source CCCS is I = alphai, the size of I can be controlled, the control current I is the current flowing into the high potential point of the first pin from the external port, I is the current of the current control current source CCCS, namely the current of the CCCS is alphai, and the current direction of the CCCS is from the 1 st pin to the 2 nd pin; the 1 st pin and the 2 nd pin are connected in series with a variable resistor R2 as a sensitivity adjusting resistor, and the variable resistor R2 is connected in parallel with a current control current source CCCS; the 2 nd pin and the 3 rd pin are connected with a voltage source VCVS controlled by voltage, wherein the 2 nd pin is a low potential point, the 3 rd pin is a high potential point, and the control voltage of the voltage source VCVS controlled by voltage is the potential difference between the 1 st pin and the 3 rd pin; the circuit structure is equivalently regarded as a negative resistance, and the 1 st pin and the 3 rd pin are connected to an external circuit. The main circuit current of the current controlled current source CCCS is control current, and the branch circuit current of the current controlled current source CCCS is control current output by amplifying alpha times. The voltage of a voltage control voltage source VCVS port is control voltage, the voltage of a branch circuit where the voltage control voltage source VCVS is located is control voltage which is amplified by beta times, and the direction of the control voltage is the direction of the voltage of an external port.

By kirchhoff's voltage law, kirchhoff's current law:

the equivalent resistance expression from the external port can be found as:alpha is the gain of the current control current source, beta is the voltage control voltage source. By analyzing the relation, the equation can be foundThe whole body is represented as a positive resistance; when in useIt can be represented as a negative resistance; when in useWhile being constant, the circuit can be written as:。

when viewed from the access port, the relationship between the equivalent resistance and α can be regarded as a formula with a slope being a negative linear function, and the adjustment range of the negative resistance is as follows:. The gain alpha is changed to realize the change of the magnitude of partial positive resistance and negative resistance with any valueThe sensitivity of the negative resistance conversion can be properly adjusted, and the rough adjustment of the negative resistance value can be realized by utilizing the characteristic under the condition that the negative resistance precision is required to be higher. After coarse tuning is finished, if the precision of the resistance value of the negative resistor is required, beta can be properly changed to realize fine tuning of the resistance value, when coarse tuning is finished, only beta is allowed to be changed, and at the moment, the whole equivalent resistance formula can be regarded as an inverse proportion functionThe slope of the inverse proportional function changes very slowly, and even if beta is slightly larger, the resistance value changes not greatly and only slightly, so that the resistance value is finely adjusted, and the resistance value of the negative resistor can be accurately adjusted.

Fig. 2 is a flow chart of steps of a method for implementing a negative resistance with a variable resistance according to the present invention, which includes the following steps: step 201, determining a required negative resistance value, and determining a required alpha value according to an existing formula; step 202, if the required alpha is too large, adjusting the size of R2 to avoid using too large alpha; step 203, adjusting the value of beta to enable the resistance value of the negative resistor to reach a required accurate degree;

the negative resistor with the variable resistance is realized, the types of the negative resistor circuits are increased, the voltage working range and the resistance range of the negative resistor are expanded, the structure is simple, the operation is stable, the influence of some internal resistances in the circuit can be accurately counteracted by the negative resistor, the characteristics of a controlled object can be improved, unnecessary zero poles are eliminated in control science and engineering, and convenience is brought to the design of a controller.

It is to be understood that the above description is not intended to limit the invention, and the invention is not limited to the above examples, and those skilled in the art can make changes, modifications, additions or substitutions within the spirit and scope of the invention, such as those using norton's theorem or daving's theorem to replace the parallel resistors of current source with the series resistors of voltage source.