CN107425819B - Amplifying circuit with respectively adjustable positive and negative gains and positive output - Google Patents

Amplifying circuit with respectively adjustable positive and negative gains and positive output Download PDF

Info

Publication number
CN107425819B
CN107425819B CN201710349197.3A CN201710349197A CN107425819B CN 107425819 B CN107425819 B CN 107425819B CN 201710349197 A CN201710349197 A CN 201710349197A CN 107425819 B CN107425819 B CN 107425819B
Authority
CN
China
Prior art keywords
resistor
output
inverting input
positive
adjustable
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Active
Application number
CN201710349197.3A
Other languages
Chinese (zh)
Other versions
CN107425819A (en
Inventor
李全民
焦营营
罗珂
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Shandong Jianzhu University
Original Assignee
Shandong Jianzhu University
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Shandong Jianzhu University filed Critical Shandong Jianzhu University
Priority to CN201710349197.3A priority Critical patent/CN107425819B/en
Publication of CN107425819A publication Critical patent/CN107425819A/en
Application granted granted Critical
Publication of CN107425819B publication Critical patent/CN107425819B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03F—AMPLIFIERS
    • H03F3/00—Amplifiers with only discharge tubes or only semiconductor devices as amplifying elements
    • H03F3/04—Amplifiers with only discharge tubes or only semiconductor devices as amplifying elements with semiconductor devices only
    • H03F3/16—Amplifiers with only discharge tubes or only semiconductor devices as amplifying elements with semiconductor devices only with field-effect devices
    • H03F3/165—Amplifiers with only discharge tubes or only semiconductor devices as amplifying elements with semiconductor devices only with field-effect devices with junction-FET's
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03F—AMPLIFIERS
    • H03F1/00—Details of amplifiers with only discharge tubes, only semiconductor devices or only unspecified devices as amplifying elements
    • H03F1/38—Positive-feedback circuit arrangements without negative feedback

Landscapes

  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Amplifiers (AREA)

Abstract

The invention discloses an amplifying circuit with respectively adjustable positive and negative gains and positive output, which comprises operational amplifiers U1A, U1B, U1C and an adjustable resistor Rw1And an adjustable resistance Rw2(ii) a Is characterized in that: the input signal IN is connected with the non-inverting input end of U1A, and the output end of U1A is connected with the non-inverting input end of U1B; the non-inverting input end of U1B passes through an adjustable resistor R in turnw1The resistor R2 is connected with the inverting input end of the U1A, the output end of the U1B is connected with the base electrode of the PNP type triode Q1 through the resistor R6, and the adjustable resistor R is sequentially connected in series between the inverting input end and the output end of the U1Cw2And a resistor R4. The amplifying circuit of the invention outputs a positive signal with the gain of k1 & gt 0 by both U1A and U1C when the input signal is positive, and outputs an amplified positive signal with the gain of k2 & lt 0 when the input signal is negative. By adjusting the adjustable resistance Rw1、Rw2The gain of the input signal of the sensor can be adjusted to be positive and negative so as to ensure the consistency of the positive and negative output characteristics of the input signal.

Description

Amplifying circuit with respectively adjustable positive and negative gains and positive output
Technical Field
The invention relates to an amplifying circuit, in particular to an amplifying circuit with respectively adjustable positive and negative gains and positive output.
Background
However, when a sensor with such characteristics is used, it is desirable that the positive and negative output characteristics thereof are consistent, which requires correction of the characteristics thereof, and the correction method generally includes gain adjustment for the positive and negative characteristics, respectively. For example, when the tension and compression sensor is under the action of tension or pressure, the output is always smaller under one condition, when the sensor is used, the amplification factor of a subsequent amplifying circuit is smaller on the one hand when the output signal is larger, and the amplification factor of the subsequent amplifying circuit is larger on the other hand when the output signal is smaller, so that the aim of consistent positive and negative output characteristics is fulfilled.
Disclosure of Invention
In order to overcome the defects of the technical problems, the invention provides an amplifying circuit with respectively adjustable positive and negative gains and positive output.
The invention discloses an amplifying circuit with respectively adjustable positive and negative gains and positive output, which comprises an operational amplifier U1A, an operational amplifier U1B, an operational amplifier U1C and an adjustable resistor Rw1And an adjustable resistance Rw2(ii) a The method is characterized in that: the input signal IN is connected with the non-inverting input end of the operational amplifier U1A, the inverting input end of U1A is connected with the power ground through a resistor R1, and the output end of U1A is connected with the non-inverting input end of the operational amplifier U1B; the non-inverting input end of U1B passes through an adjustable resistor R in turnw1The resistor R2 is connected with the inverting input end of the U1A, the inverting input end of the U1B is connected with the power ground, the output end of the U1B is connected with the base electrode of the PNP type triode Q1 through the resistor R6, the emitter electrode of the Q1 is connected with the power ground, and the collector electrode of the Q1 is connected with the non-inverting input end of the operational amplifier U1C; the non-inverting input end of U1C is connected with the output end of U1A through a resistor R5, the inverting input end of U1C is connected with the output end of U1A through a resistor R3, and an adjustable resistor R is connected in series between the inverting input end of U1C and the output end thereof in sequencew2And the output ends of the resistors R4 and U1C output the output signal OUT of the amplifying circuit.
The invention relates to an amplifying circuit with respectively adjustable positive and negative gains and positive output, and the voltage of an input signal is set as UINThe voltage of the output signal is UOUTThe voltage at the output end of the operational amplifier U1A is UpAnd then:
when inputting signal UINWhen the content is more than or equal to 0,
Figure BDA0001297310890000021
wherein the content of the first and second substances,
Figure BDA0001297310890000022
Rw1is an adjustable resistor Rw1Resistance values in the access circuit;
when inputting signal UINWhen the ratio is less than 0, the reaction mixture is,
Figure BDA0001297310890000023
wherein the content of the first and second substances,
Figure BDA0001297310890000024
K2＝kbka，Rw2is an adjustable resistor Rw2Resistance values in the access circuit.
The invention relates to an amplifying circuit with respectively adjustable positive and negative gains and positive output, which comprises a resistor R3, a resistor R4 and an adjustable resistor Rw2The resistance value of (1) satisfies:
R3＝R4+0.5Rw2maxwherein R isw2maxIs an adjustable resistor Rw2A maximum resistance value accessible in the circuit; so that the adjustable resistance Rw2Gain k of operational amplifier U1C in the process of moving from the middle to the two sidesbVarying on both sides-1.
The invention has the beneficial effects that: the amplifying circuit comprises operational amplifiers U1A, U1B, U1C and an adjustable resistor Rw1、Rw2The input signal IN is connected with the non-inverting input end of U1A, the output of U1A is connected with the non-inverting input end of U1B, the output of U1B is connected with the base electrode of Q1, and the non-inverting input end of U1C is connected with the collector electrode of Q1; when the input signal is positive, U1A and U1C both output a positive signal with gain k1 > 0, and when the input signal is negative, U1B outputs a low level to turn on Q1, so that U1C outputs an amplified positive signal with gain k2 < 0. By adjusting the adjustable resistance Rw1The resistance value connected into the circuit can adjust the gain of the sensor input signal as the positive time, and the adjustable resistance R is adjustedw2The resistance value in the access circuit can adjust the gain when the input signal of the sensor is negative so as to ensure the consistency of the positive and negative output characteristics of the sensor.
Drawings
Fig. 1 is a circuit diagram of an amplifying circuit of the present invention in which positive and negative gains are respectively adjustable and both outputs are positive.
In the figure: 1 operational amplifier U1A, 2 operational amplifier U1B, 3 operational amplifier U1C, 4 adjustable resistor R w15 Adjustable resistance Rw2。
In the figure: 1 operational amplifier U1A, 2 operational amplifier U1B, 3 operational amplifier U1C, 4 adjustable resistanceR w15 Adjustable resistance Rw2。
Detailed Description
The invention is further described with reference to the following figures and examples.
As shown in FIG. 1, a circuit diagram of an amplifying circuit with positive and negative gains adjustable respectively and positive output according to the present invention is shown, which is composed of an operational amplifier U1A (1), an operational amplifier U1B (2), an operational amplifier U1C (3), and an adjustable resistor Rw1(4) Adjustable resistance Rw2(5) And a PNP transistor Q1, wherein the input signal IN is connected to the non-inverting input terminal of the operational amplifier U1A, the inverting input terminal of U1A is connected to the power ground via a resistor R1, and the inverting input terminal of U1A is connected to the power ground via a resistor R2 and an adjustable resistor Rw1Is connected to the non-inverting input of operational amplifier U1B, and the output of U1A is connected to the non-inverting input of U1B. By adjusting the adjustable resistance Rw1The resistance value of the access circuit can adjust the gain of the operational amplifier U1A.
The inverting input of the operational amplifier U1B is shown connected directly to power ground, the non-inverting input of U1B is connected to the non-inverting input of operational amplifier U1C via resistor R5, and the non-inverting input of U1B is connected to the inverting input of U1C via resistor R3. The output end of the U1B is connected with the base of a PNP type triode Q1 through a resistor R6, the emitter of the Q1 is connected with the power ground, and the collector of the Q1 is connected with the non-inverting input end of an operational amplifier U1C. The high-low level signal output by the U1B can control the on-off state of the transistor Q1, and the on-off state of the Q1 can determine whether the gain of the operational amplifier U1C has an effect on the output signal of the U1A.
The inverting input terminal of the operational amplifier U1C is shown passing through an adjustable resistor R in sequencew2The resistor R4 is connected to the output terminal of U1C, and the output terminal of U1C forms the output signal OUT of the amplifier circuit.
Setting the voltage of the input signal to UINThe voltage of the output signal is UOUTThe voltage at the output end of the operational amplifier U1A is UpAnd then:
when inputting signal UINWhen the voltage is more than or equal to 0, the operational amplifier U1A outputs high level, and the voltage U of the output end thereofp＝[1+(R2+Rw1)/R1]UIN，Up> 0, so operational amplifier U1B outputs a high level, turning off transistor Q1; meanwhile, due to the 'virtual break' action of the equidirectional input end (5 end) and the inverting input end (6 end) of the operational amplifier U1C, no current passes through the resistor R5, so that the voltages at the 5 end and the 6 end of the U1C and the P point of the output end of the U1A are equal, no current passes through the R3, and the adjustable resistor Rw2Resistor R4 also has no current flowing through it. So that the voltage level of the output terminal OUT (terminal 7) of U1C is equal to the voltage levels of the terminals 6, 5 and p, therefore:
Figure BDA0001297310890000041
wherein the content of the first and second substances,
Figure BDA0001297310890000042
Rw1is an adjustable resistor Rw1Resistance values in the access circuit.
When inputting signal UINWhen the voltage is less than 0, the voltage of the non-inverting input end of the operational amplifier U1A is lower than that of the inverting input end, the output end of U1A outputs low level, and U is lower than the voltage of the inverting input endp< 0, so that the voltage of the non-inverting input terminal of U1B is lower than that of the inverting input terminal, U1B outputs low level, the low level output by U1B makes the triode Q1 conduct in saturation, and after the Q1 is conducted, the non-inverting input terminal of the operational amplifier U1C is grounded, and since the 5 terminal and the 6 terminal of U1C are equipotential and no current flows, the relation between the voltage of the output terminal of U1C and the input signal voltage can be obtained as follows:
Figure BDA0001297310890000043
wherein the content of the first and second substances,
Figure BDA0001297310890000044
K2＝kbka＜0，Rw2is an adjustable resistor Rw2Resistance values in the access circuit.
In this way, the output signal U of the amplifying circuit is madeOUTAnd an input signal UINThe relationship of (1) is:
Figure BDA0001297310890000045
therefore, no matter the signal U input by the sensorINThe output signal can be obtained as positive or negative signal, and the adjustable resistor R is adjustedw1The resistance value connected into the circuit can adjust the gain of the sensor input signal as the positive time, and the adjustable resistance R is adjustedw2The resistance value in the access circuit can adjust the gain when the input signal of the sensor is negative so as to ensure the consistency of the positive and negative output characteristics of the sensor.
Resistor R3, resistor R4 and adjustable resistor Rw2The resistance value of (1) satisfies: r3＝R4+0.5Rw2maxWherein R isw2maxIs an adjustable resistor Rw2A maximum resistance value accessible in the circuit; at this time
Figure BDA0001297310890000051
So that the adjustable resistance Rw2Gain k of operational amplifier U1C in the process of moving from the middle to the two sidesbVarying on both sides-1.

Claims (3)

1. The amplifying circuit comprises an operational amplifier U1A (1), an operational amplifier U1B (2), an operational amplifier U1C (3) and an adjustable resistor Rw1(4) And an adjustable resistance Rw2(5) (ii) a The method is characterized in that: the input signal IN is connected with the non-inverting input end of the operational amplifier U1A, the inverting input end of U1A is connected with the power ground through a resistor R1, and the output end of U1A is connected with the non-inverting input end of the operational amplifier U1B; the non-inverting input end of U1B passes through an adjustable resistor R in turnw1The resistor R2 is connected with the inverting input end of the U1A, the inverting input end of the U1B is connected with the power ground, the output end of the U1B is connected with the base electrode of the PNP type triode Q1 through the resistor R6, the emitter electrode of the Q1 is connected with the power ground, and the collector electrode of the Q1 is connected with the non-inverting input end of the operational amplifier U1C; the non-inverting input terminal of U1C is connected to the output terminal of U1A via resistor R5, the inverting input terminal of U1C is connected to the output terminal of U1A via resistor R3, and the inverting input terminal of U1C is connected to its outputThe ends are connected in series with an adjustable resistor Rw2And the output ends of the resistors R4 and U1C output the output signal OUT of the amplifying circuit.
2. The amplifying circuit according to claim 1, wherein the positive and negative gains are respectively adjustable, and the output is positive, and wherein: setting the voltage of the input signal to UINThe voltage of the output signal is UOUTThe voltage at the output end of the operational amplifier U1A is UpAnd then:
when inputting signal UINWhen the content is more than or equal to 0,
Figure FDA0001297310880000011
wherein the content of the first and second substances,
Figure FDA0001297310880000012
Rw1is an adjustable resistor Rw1Resistance values in the access circuit;
when inputting signal UINWhen the ratio is less than 0, the reaction mixture is,
Figure FDA0001297310880000013
wherein the content of the first and second substances,
Figure FDA0001297310880000014
K2＝kbka，Rw2is an adjustable resistor Rw2Resistance values in the access circuit.
3. The amplifying circuit according to claim 2, wherein the positive and negative gains are respectively adjustable, and the output is positive, and wherein: the resistor R3, the resistor R4 and the adjustable resistor Rw2The resistance value of (1) satisfies:
R3＝R4+0.5Rw2maxwherein R isw2maxIs an adjustable resistor Rw2A maximum resistance value accessible in the circuit; so that the adjustable resistance Rw2In the process of changing from the middle to two sides, the operational amplifierGain k of U1CbVarying on both sides-1.
CN201710349197.3A 2017-05-17 2017-05-17 Amplifying circuit with respectively adjustable positive and negative gains and positive output Active CN107425819B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN201710349197.3A CN107425819B (en) 2017-05-17 2017-05-17 Amplifying circuit with respectively adjustable positive and negative gains and positive output

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN201710349197.3A CN107425819B (en) 2017-05-17 2017-05-17 Amplifying circuit with respectively adjustable positive and negative gains and positive output

Publications (2)

Publication Number Publication Date
CN107425819A CN107425819A (en) 2017-12-01
CN107425819B true CN107425819B (en) 2020-10-27

Family

ID=60425640

Family Applications (1)

Application Number Title Priority Date Filing Date
CN201710349197.3A Active CN107425819B (en) 2017-05-17 2017-05-17 Amplifying circuit with respectively adjustable positive and negative gains and positive output

Country Status (1)

Country Link
CN (1) CN107425819B (en)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN112629719A (en) * 2020-12-29 2021-04-09 山东建筑大学 Draw pressure signal absolute value output conditioning circuit

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101702584A (en) * 2009-11-28 2010-05-05 天津市诺尔电气有限公司 Precise amplification, rectification and filtering circuit
CN101847966A (en) * 2009-09-25 2010-09-29 上海大学 Bipolar zero position and gain adjustable amplifier and analog signal conditioner
CN201608654U (en) * 2009-11-28 2010-10-13 天津诺尔哈顿电器制造有限公司 Precision amplifying, rectifying and filtering circuit
CN204926101U (en) * 2015-08-18 2015-12-30 中航太克（厦门）电子有限公司 High accuracy absolute value circuit
CN206077340U (en) * 2016-09-07 2017-04-05 南京铁道职业技术学院 A kind of photodiode amplifying circuit with temperature compensation function

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101847966A (en) * 2009-09-25 2010-09-29 上海大学 Bipolar zero position and gain adjustable amplifier and analog signal conditioner
CN101702584A (en) * 2009-11-28 2010-05-05 天津市诺尔电气有限公司 Precise amplification, rectification and filtering circuit
CN201608654U (en) * 2009-11-28 2010-10-13 天津诺尔哈顿电器制造有限公司 Precision amplifying, rectifying and filtering circuit
CN204926101U (en) * 2015-08-18 2015-12-30 中航太克（厦门）电子有限公司 High accuracy absolute value circuit
CN206077340U (en) * 2016-09-07 2017-04-05 南京铁道职业技术学院 A kind of photodiode amplifying circuit with temperature compensation function

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
单管绝对值电路;沙振舜;《电子技术》;19820630(第6期);40-41 *
只用一个晶体管的全波信号整流器;David L.Albean;《电子产品实际》;19971104(第11期);66-67 *

Also Published As

Publication number Publication date
CN107425819A (en) 2017-12-01

Similar Documents

Publication Publication Date Title
US9595931B2 (en) Two differential amplifier configuration
CN103563252B (en) Automatic gain control circuit
CN108073218B (en) Operation amplifier circuit and band gap reference
US20100283542A1 (en) Linear transimpedance amplifier with wide dynamic range for high rate applications
CN109388173B (en) Current compensation circuit
CN107425819B (en) Amplifying circuit with respectively adjustable positive and negative gains and positive output
US6933786B1 (en) Amplifier circuit and method
US20080129384A1 (en) Variable gain amplifier circuit
CN107612517B (en) Gain programmable amplifier based on double-input operational transconductance amplifier
CN110471482A (en) A kind of voltage calibration method and calibration circuit
CN107171650A (en) Variable-gain amplification circuit
US20090009242A1 (en) Line driver capable of automatically adjusting output impedance
CN110412342B (en) Quick current detection circuit
CN111293699B (en) Method for realizing line loss voltage complete compensation and intelligent power supply circuit
CN106941343A (en) A kind of linear variable gain amplifier
CN111404491A (en) T-shaped resistance network trans-impedance amplifying circuit with automatic voltage compensation function
CN103001596A (en) Gain programmable fully-differential amplifier with output common-mode imbalance correction
CN211063578U (en) T-shaped resistance network trans-impedance amplifying circuit with automatic voltage compensation function
CN113839633A (en) Adjustable gain amplifier
JP2012151539A (en) Transmission power control circuit
CN114747138A (en) Logarithmic amplifier
CN210626553U (en) Current detection circuit capable of being adjusted quickly and easily
CN104617899A (en) differential amplifier and electronic device
CN211018769U (en) Variable gain circuit of toxic gas sensor circuit
CN106788304B (en) Automatic gain control circuit and audio equipment

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
GR01 Patent grant
GR01 Patent grant