CN217445338U - Differential sampling signal amplifying circuit capable of inhibiting common-mode interference and air conditioner - Google Patents
Differential sampling signal amplifying circuit capable of inhibiting common-mode interference and air conditioner Download PDFInfo
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- CN217445338U CN217445338U CN202221149460.7U CN202221149460U CN217445338U CN 217445338 U CN217445338 U CN 217445338U CN 202221149460 U CN202221149460 U CN 202221149460U CN 217445338 U CN217445338 U CN 217445338U
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Abstract
The utility model provides a can restrain common mode interference's differential sampling signal amplifier circuit and air conditioner, include: the bias voltage generating circuit comprises a signal input end, an eighth resistor, a fourth resistor, a signal amplifying module and a bias voltage generating module, wherein the signal input end comprises a first signal input end and a second signal input end, the first signal input end, the fourth resistor and the signal amplifying module are sequentially and electrically connected, and the second signal input end, the eighth resistor and the signal amplifying module are sequentially and electrically connected; the signal amplification module is used for amplifying an input signal; the bias voltage generating module is electrically connected between the signal amplifying module and the fourth resistor; the bias voltage generating module is used for generating bias voltage and outputting the bias voltage to the signal amplifying module; the circuit is simple in structure, and when the resistors meet the corresponding relational expressions, common-mode interference in the sampling amplifying circuit can be eliminated, and the accuracy of sampling signals is greatly improved.
Description
Technical Field
The utility model relates to a signal acquisition technical field particularly, relates to a can restrain differential sampling signal amplifier circuit and air conditioner of common mode interference.
Background
At present, current sampling signals of an external unit of a variable frequency air conditioner are weak signals, and generally can be sent to a chip AD conversion port for analog-to-digital conversion after passing through a differential amplification circuit.
SUMMERY OF THE UTILITY MODEL
In view of the above, the present invention provides a differential sampling signal amplifying circuit and an air conditioner capable of suppressing common mode interference, so as to solve the above problems.
In order to achieve the above purpose, the technical scheme of the utility model is realized like this:
the utility model provides a can restrain differential sampling signal amplifier circuit of common mode interference, including signal input part, eighth resistance, fourth resistance, signal amplification module and bias voltage generation module, wherein, signal input part is used for receiving input signal, signal input part includes first signal input part and second signal input part, first signal input part, fourth resistance and signal amplification module electricity in proper order are connected, second signal input part, eighth resistance and signal amplification module electricity in proper order are connected; the signal amplification module is used for amplifying an input signal; the bias voltage generating module is electrically connected between the signal amplifying module and the fourth resistor; the bias voltage generating module is used for generating bias voltage and outputting the bias voltage to the signal amplifying module.
According to the differential sampling signal amplifying circuit capable of inhibiting common-mode interference, the common-mode interference signals in the sampling amplifying circuit can be eliminated through the circuit structure, and the accuracy of the sampling signals is greatly improved.
Furthermore, the signal amplification module includes an operational amplifier and a seventh resistor, the operational amplifier includes an inverting input terminal, a non-inverting input terminal and a signal output terminal, the inverting input terminal of the operational amplifier is electrically connected to the eighth resistor, the inverting input terminal of the operational amplifier is electrically connected to the signal output terminal of the operational amplifier after being connected in series to the seventh resistor, and the non-inverting input terminal of the operational amplifier is electrically connected to the fourth resistor and the bias voltage generation module.
Usually, the connection mode between the first signal input end and the operational amplifier and the connection mode between the second signal input end and the operational amplifier and the amplification factor of the signal amplification module can be set by a user, so that the user can obtain the relational expression which the eighth resistor and the seventh resistor should satisfy under the condition of a certain amplification factor, and specific parameters are conveniently set for the eighth resistor and the seventh resistor.
Further, the bias voltage generation module includes a power supply, a fifth resistor and a sixth resistor, the power supply is connected in series with the sixth resistor and the fifth resistor in sequence and then grounded, and a non-inverting input terminal of the operational amplifier is electrically connected between the fifth resistor and the sixth resistor.
The embodiment of the utility model provides a bias voltage generation module utilizes as bias voltage input to operational amplifier's in-phase input end after fifth resistance and the sixth resistance partial pressure through setting up power, fifth resistance and sixth resistance, can practice thrift the cost, has reduced the circuit complexity again.
Further, the resistance values of the resistors satisfy the following relation: r8 ═ R4, and 1/R6+1/R5 ═ 1/R7, where R8 is the eighth resistor, R4 is the fourth resistor, R5 is the fifth resistor, R6 is the sixth resistor, and R7 is the seventh resistor.
In the circuit structure, when the resistance of each resistor meets the relational expression, a common mode interference source in the sampling amplifying circuit can be eliminated, so that the accuracy of a sampling signal is greatly improved.
Further, the resistances of the resistors R7 and R4 are required to satisfy: r7 > R4.
In the present application, when R7 > R4, R4 ═ R8 indicates that R7 > R8, and 1/R6+1/R5 ═ 1/R7 indicates that R5 > R7, and R6 > R7 indicate that the relationship between R7 and R4 is defined, and the relationship between other resistances can be defined.
Further, the resistances of the resistors R4, R5, R6 and R7 are required to satisfy: 100 omega < R4 < 5k omega, 1k omega < R5 < 100k omega, 1k omega < R6 < 100k omega, 1k omega < R7 < 50k omega.
The resistance of each resistance all sets for the value range of broad in this application, has enlarged the range of application of circuit structure on the one hand, and on the other hand, convenience of customers adjusts circuit structure.
Further, when the resistance values of the resistors satisfy the relation: when R8 is R4 and 1/R6+1/R5 is 1/R7, the bias voltage satisfies the formula:
wherein, V ref Vcc is a supply voltage for the bias voltage.
The bias voltage is set by a user, when the user sets parameters, the relation satisfied by the parameters of each component can be obtained through the determined amplification factor, the bias voltage and the corresponding formula, and finally the parameters of each component are determined.
Further, the first signal input end is electrically connected with a non-inverting input end of the operational amplifier, and the second signal input end is electrically connected with an inverting input end of the operational amplifier.
When the first signal input end is connected with the non-inverting input end of the operational amplifier and the second signal input end is connected with the inverting input end of the operational amplifier, the signal amplification module plays a role in forward amplification, and the amplification factor of the signal amplification module is greater than 1.
Further, the first signal input terminal and the second signal input terminal are separately grounded, or the first signal input terminal and the second signal input terminal are grounded after being connected in parallel.
The first signal input end and the second signal input end are grounded after being connected in parallel, so that the circuit structure is simpler and the wiring is convenient.
The utility model also provides an air conditioner, including above the difference sampling signal amplifier circuit that can restrain common mode interference.
Compared with the prior art, ability suppression common mode interference's difference sampling signal amplifier circuit and air conditioner have following advantage:
the differential sampling signal amplification circuit capable of inhibiting common-mode interference and the air conditioner comprise a signal input end, an eighth resistor, a fourth resistor, a signal amplification module and a bias voltage generation module, wherein the signal input end is used for receiving input signals, the signal input end comprises a first signal input end and a second signal input end, the first signal input end, the fourth resistor and the signal amplification module are sequentially and electrically connected, and the second signal input end, the eighth resistor and the signal amplification module are sequentially and electrically connected; the signal amplification module is used for amplifying an input signal; the bias voltage generating module is electrically connected between the signal amplifying module and the fourth resistor; the bias voltage generating module is used for generating bias voltage and outputting the bias voltage to the signal amplifying module; the circuit is simple in structure, and when the resistors meet the relational expression, common-mode interference in the sampling amplifying circuit can be eliminated, and the accuracy of sampling signals is greatly improved.
Drawings
Fig. 1 is a circuit diagram of a differential sampling signal amplifying circuit capable of suppressing common mode interference according to an embodiment of the present invention.
Description of reference numerals:
1-differential sampling signal amplifying circuit capable of suppressing common mode interference; 2-a signal input; 21-a first signal input; 22-a second signal input; 3-a signal amplification module; 4-bias voltage generation module.
Detailed Description
In order to make the aforementioned objects, features and advantages of the present invention more comprehensible, embodiments accompanied with figures are described in detail below.
Example 1
As shown in fig. 1, the utility model provides a can restrain differential sampling signal amplifier circuit 1 of common mode interference, include: the bias voltage generating circuit comprises a signal input end 2, an eighth resistor, a fourth resistor, a signal amplifying module 3 and a bias voltage generating module 4, wherein the signal input end 2 is used for receiving input signals, the signal input end 2 comprises a first signal input end 21 and a second signal input end 22, the first signal input end 21, the fourth resistor and the signal amplifying module 3 are sequentially and electrically connected, and the second signal input end 22, the eighth resistor and the signal amplifying module 3 are sequentially and electrically connected; the signal amplification module 3 is used for amplifying an input signal; the bias voltage generating module 4 is electrically connected between the signal amplifying module 3 and the fourth resistor; the bias voltage generating module 4 is configured to generate a bias voltage and output the bias voltage to the signal amplifying module 3.
The utility model discloses a can restrain differential sampling signal amplifier circuit 1 of common mode interference, can eliminate the common mode interference signal among the sampling amplifier circuit through foretell circuit structure, improve sampling signal's accuracy by a wide margin.
Preferably, the input signal can be a direct current signal or an alternating current signal, and can be collected by a signal collecting device and transmitted to the signal input end 2, or can be received by a signal transmitting device and transmitted to the signal input end 2.
As a preferred example of the present invention, the signal amplification module 3 includes an operational amplifier IC2 and a seventh resistor R7, the operational amplifier IC2 includes an inverting input terminal, a non-inverting input terminal and a signal output terminal, the inverting input terminal of the operational amplifier IC2 is electrically connected to the eighth resistor R8, the inverting input terminal of the operational amplifier IC2 is connected in series to the seventh resistor R7 and then electrically connected to the signal output terminal of the operational amplifier, and the non-inverting input terminal of the operational amplifier IC2 is electrically connected to the fourth resistor R4 and the bias voltage generation module 4.
Specifically, the amplification factor of the signal amplification module 3 is determined by the connection manner between the first signal input terminal 21 and the second signal input terminal 22 and the operational amplifier IC2, the eighth resistor R8, and the seventh resistor R7.
Specifically, the connection mode between the first signal input terminal 21 and the second signal input terminal 22 and the operational amplifier IC2 and the amplification factor of the signal amplification module 3 can be set by the user, so that the user can obtain the relational expression that the eighth resistor R8 and the seventh resistor R7 should satisfy under the condition of a certain amplification factor, and set specific parameters for the eighth resistor R8 and the seventh resistor R7 conveniently.
As a preferred example of the present invention, the bias voltage generating module 4 includes a power supply, a sixth resistor R6 and a fifth resistor R5, the power supply is serially connected in series with the sixth resistor R6 and the fifth resistor R5 and then grounded, and the non-inverting input terminal of the operational amplifier IC2 is electrically connected between the fifth resistor R5 and the sixth resistor R6.
The embodiment of the utility model provides a bias voltage generates module 4 is through setting up power, fifth resistance R5 and sixth resistance R6, utilizes and inputs to operational amplifier IC 2's in-phase input end as bias voltage after fifth resistance R5 and the voltage division of sixth resistance R6, can practice thrift the cost, has reduced the circuit complexity again.
As a preferred example of the present invention, the resistance of each resistor in the differential sampling signal amplifying circuit 1 capable of suppressing common mode interference needs to satisfy the following formula: r8 ═ R4, and 1/R6+1/R5 ═ 1/R7, where R8 is the eighth resistor, R4 is the fourth resistor, R5 is the fifth resistor, R6 is the sixth resistor, and R7 is the seventh resistor.
Specifically, the signal amplification module 3 is a differential amplification circuit, and the differential amplification circuit utilizes the symmetry and negative feedback action of circuit parameters, so that the circuit parameters of two paths of the inverting input terminal and the non-inverting input terminal of the operational amplifier IC2 have symmetry, and therefore, R4 is R8.
Specifically, the bias voltage generation module 4 is electrically connected to the signal amplification module 3, and the bias voltage generation module 4 generates a bias voltage and outputs the bias voltage to the signal amplification module 3.
In particular, the non-inverting terminal V of the operational amplifier is utilized + And an inverting terminal V _ The virtual short and the virtual break theorem establish the following three equations:
V + ＝V- ③
is transformed by the third step:
wherein Vout is an output signal, Vcm is a common mode interference source, Vs is a signal source, Vcc is a power voltage, R8 is an eighth resistor, R4 is a fourth resistor, R5 is a fifth resistor, R6 is a sixth resistor, and R7 is a seventh resistor.
When the resistance values of the resistors meet the formula: r8 ═ R4, and 1/R6+1/R5 ═ 1/R7, then in equation (R):
fourthly, the following can be changed:
the common-mode interference source Vcm in the output signal Vout is offset, that is, the common-mode interference source Vcm in the sampling amplifying circuit can be eliminated by the circuit structure in the application, and the accuracy of the sampling signal is greatly improved.
As a preferred example of the present invention, the resistances of the resistors R7 and R4 need to satisfy: r7 > R4.
Specifically, R7 > R8 because R7 > R4 and R4 ═ R8, and R5 > R7 and R6 > R7 because 1/R6+1/R5 ═ 1/R7.
As a preferred example of the present invention, the resistances of the resistors R4, R5, R6 and R7 should satisfy: 100 omega < R4 < 5k omega, 1k omega < R5 < 100k omega, 1k omega < R6 < 100k omega, 1k omega < R7 < 50k omega.
Preferably, the fourth resistor R4 is 1k Ω, the fifth resistor R5 is 20k Ω, the sixth resistor R6 is 20k Ω, and the seventh resistor R7 is 10k Ω.
As a preferred example of the present invention, when the resistance of each resistor satisfies the relation: when R8 is R4 and 1/R6+1/R5 is 1/R7, the bias voltage satisfies the formula:
wherein, V ref Vcc is a supply voltage for the bias voltage.
Specifically, the general bias voltage is set by the user, and when the user sets parameters, the relational expression satisfied by the parameters of each component can be obtained through the determined amplification factor, the bias voltage and the corresponding formula, and finally the parameters of each component are determined.
As a preferred example of the present invention, the first signal input terminal 21 is electrically connected to the non-inverting input terminal of the operational amplifier, and the second signal input terminal 22 is electrically connected to the inverting input terminal of the operational amplifier.
Specifically, when the first signal input end 21 is connected to the non-inverting input end of the operational amplifier, and the second signal input end 22 is connected to the inverting input end of the operational amplifier, the signal amplification module 3 plays a role of forward amplification, and the amplification factor a of the signal amplification module 3 is greater than 1; preferably, when the first signal input terminal 21 is connected to the inverting input terminal of the operational amplifier and the second signal input terminal 22 is connected to the non-inverting input terminal of the operational amplifier, the signal amplification module 3 performs an inverse reduction function, and the amplification factor 1 > a > 0 of the signal amplification module 3, where a is the amplification factor, R8 is the eighth resistor, and R7 is the seventh resistor.
As a preferred example of the present invention, the first signal input terminal 21 and the second signal input terminal 22 are grounded separately, or the first signal input terminal 21 and the second signal input terminal 22 are grounded after being connected in parallel.
Specifically, the first signal input terminal 21 and the second signal input terminal 22 are grounded after being connected in parallel, so that the circuit structure is simpler.
In addition, the application also provides an air conditioner, the air conditioner has foretell difference sampling signal amplifier circuit that can restrain common mode interference.
To sum up, the embodiment of the present invention provides a differential sampling signal amplifying circuit and an air conditioner capable of suppressing common mode interference, including a signal input end 2, an eighth resistor, a fourth resistor, a signal amplifying module 3 and a bias voltage generating module 4, wherein the signal input end 2 is used for receiving an input signal, the signal input end 2 includes a first signal input end 21 and a second signal input end 22, the first signal input end 21, the fourth resistor and the signal amplifying module 3 are electrically connected in sequence, and the second signal input end 22, the eighth resistor and the signal amplifying module 3 are electrically connected in sequence; the signal amplification module 3 is used for amplifying an input signal; the bias voltage generating module 4 is electrically connected between the signal amplifying module 3 and the fourth resistor; the bias voltage generating module 4 is configured to generate a bias voltage and output the bias voltage to the signal amplifying module 3; the circuit is simple in structure, and when the resistors meet the relational expression, common mode interference in the sampling amplifying circuit can be eliminated, and the accuracy of sampling signals is greatly improved.
Although the present invention is disclosed above, the present invention is not limited thereto. Various changes and modifications can be made by one skilled in the art without departing from the spirit and scope of the invention, and the scope of the invention should be determined by the appended claims.
Claims (10)
1. The differential sampling signal amplification circuit capable of suppressing common-mode interference is characterized by comprising a signal input end (2), an eighth resistor, a fourth resistor, a signal amplification module (3) and a bias voltage generation module (4), wherein the signal input end (2) is used for receiving input signals, the signal input end (2) comprises a first signal input end (21) and a second signal input end (22), the first signal input end (21), the fourth resistor and the signal amplification module (3) are sequentially and electrically connected, and the second signal input end (22), the eighth resistor and the signal amplification module (3) are sequentially and electrically connected; the signal amplification module (3) is used for amplifying an input signal; the bias voltage generation module (4) is electrically connected between the signal amplification module (3) and the fourth resistor; the bias voltage generating module (4) is used for generating a bias voltage and outputting the bias voltage to the signal amplifying module (3).
2. The differential sampling signal amplifying circuit capable of suppressing common mode interference according to claim 1, wherein the signal amplifying module (3) comprises an operational amplifier and a seventh resistor, the operational amplifier comprises an inverting input terminal, a non-inverting input terminal and a signal output terminal, the inverting input terminal of the operational amplifier is electrically connected to the eighth resistor, the inverting input terminal of the operational amplifier is electrically connected to the signal output terminal of the operational amplifier after being connected in series with the seventh resistor, and the non-inverting input terminal of the operational amplifier is electrically connected to the fourth resistor and the bias voltage generating module (4).
3. The differential sampling signal amplifying circuit capable of suppressing the common mode interference according to claim 1, wherein the bias voltage generating module (4) comprises a power supply, a fifth resistor and a sixth resistor, the power supply is connected in series with the sixth resistor and the fifth resistor in sequence and then grounded, and a non-inverting input terminal of an operational amplifier is electrically connected between the fifth resistor and the sixth resistor.
4. The differential sampling signal amplifying circuit capable of suppressing the common mode interference according to any one of claims 2 or 3, wherein the resistance values of the resistors satisfy the following relation: r8 ═ R4, and 1/R6+1/R5 ═ 1/R7, where R8 is the eighth resistor, R4 is the fourth resistor, R5 is the fifth resistor, R6 is the sixth resistor, and R7 is the seventh resistor.
5. The differential sampling signal amplifying circuit capable of suppressing common mode interference according to claim 4, wherein the resistances of the resistors R7 and R4 are required to satisfy: r7 > R4.
6. The differential sampling signal amplifying circuit capable of suppressing common mode interference according to claim 4, wherein the resistances of the resistors R4, R5, R6 and R7 are required to satisfy: 100 omega < R4 < 5k omega, 1k omega < R5 < 100k omega, 1k omega < R6 < 100k omega, 1k omega < R7 < 50k omega.
7. The differential sampling signal amplifying circuit capable of suppressing common mode interference according to claim 4, wherein when the resistance values of the resistors satisfy the relation: when R8 is R4 and 1/R6+1/R5 is 1/R7, the bias voltage satisfies the formula:
wherein, V ref Vcc is a supply voltage for the bias voltage.
8. Differential sampling signal amplification circuit capable of suppressing common mode interference according to claim 1, characterized in that the first signal input (21) is electrically connected to a non-inverting input of an operational amplifier and the second signal input (22) is electrically connected to an inverting input of the operational amplifier.
9. The differential sampling signal amplifying circuit capable of suppressing common mode interference according to claim 8, wherein the first signal input terminal (21) and the second signal input terminal (22) are grounded separately, or the first signal input terminal (21) and the second signal input terminal (22) are grounded after being connected in parallel.
10. An air conditioner, characterized in that the air conditioner is provided with the differential sampling signal amplifying circuit capable of suppressing common mode interference according to any one of claims 1 to 9.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202221149460.7U CN217445338U (en) | 2022-05-13 | 2022-05-13 | Differential sampling signal amplifying circuit capable of inhibiting common-mode interference and air conditioner |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202221149460.7U CN217445338U (en) | 2022-05-13 | 2022-05-13 | Differential sampling signal amplifying circuit capable of inhibiting common-mode interference and air conditioner |
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| Publication Number | Publication Date |
|---|---|
| CN217445338U true CN217445338U (en) | 2022-09-16 |
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| Application Number | Title | Priority Date | Filing Date |
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| CN202221149460.7U Active CN217445338U (en) | 2022-05-13 | 2022-05-13 | Differential sampling signal amplifying circuit capable of inhibiting common-mode interference and air conditioner |
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| CN (1) | CN217445338U (en) |
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- 2022-05-13 CN CN202221149460.7U patent/CN217445338U/en active Active
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