CN107942787B - Analog signal multiplexing circuit and analog signal acquisition circuit - Google Patents
Analog signal multiplexing circuit and analog signal acquisition circuit Download PDFInfo
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- CN107942787B CN107942787B CN201711142835.0A CN201711142835A CN107942787B CN 107942787 B CN107942787 B CN 107942787B CN 201711142835 A CN201711142835 A CN 201711142835A CN 107942787 B CN107942787 B CN 107942787B
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- G05B—CONTROL OR REGULATING SYSTEMS IN GENERAL; FUNCTIONAL ELEMENTS OF SUCH SYSTEMS; MONITORING OR TESTING ARRANGEMENTS FOR SUCH SYSTEMS OR ELEMENTS
- G05B19/00—Programme-control systems
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- G05B19/04—Programme control other than numerical control, i.e. in sequence controllers or logic controllers
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- G—PHYSICS
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- G05B—CONTROL OR REGULATING SYSTEMS IN GENERAL; FUNCTIONAL ELEMENTS OF SUCH SYSTEMS; MONITORING OR TESTING ARRANGEMENTS FOR SUCH SYSTEMS OR ELEMENTS
- G05B2219/00—Program-control systems
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Abstract
The embodiment of the invention provides an analog signal multiplexing circuit and an analog signal acquisition circuit, and relates to the technical field of analog signal acquisition. The switch module is electrically connected with the voltage-current conversion module and the signal output end respectively, and the output end of the voltage-current conversion module is electrically connected with a load; therefore, the output state of the switching analog signal multiplexing circuit is achieved by controlling the on state of the switch module, when the switch module is in the on state or the off state, the analog signal multiplexing circuit outputs analog quantity voltage or load sampling signals respectively, and meanwhile, because the analog signal multiplexing circuit is controlled by the pulse width modulation signals in the sampling process, the effect of adjusting the load measuring range can be achieved by controlling the duty ratio of the pulse width modulation signals, so that the multiplexing of the analog quantity voltage output and the resistance measuring range can be adjusted, the circuit is simplified, and the general degree of a control product is improved.
Description
Technical Field
The invention relates to the technical field of analog signal acquisition, in particular to an analog signal multiplexing circuit and an analog signal acquisition circuit.
Background
With the rapid development of the engineering machinery market, the types of products are more and more, the input and output pin resources of the controller are different for different products, and in order to meet the input and output resource requirements of different customers and meet the design goal of the controller product generalization, the input and output pin resources of the controller need to be reused as much as possible. Among various sensors of construction machinery, a resistive sensor is most widely applied due to high cost performance, such as analog signals of fuel oil level, cooling liquid temperature and the like. Because the measuring ranges of the resistance sensors are different, in order to meet the requirements of the measuring ranges and the resolution ratio, the aim of adjusting the measuring ranges is needed to be achieved. In the field application of engineering machinery, a controller needs to provide power supply voltage for an external sensor, and the power supply voltage can be adjusted within the range of 0-10V according to different customer requirements.
In the existing controller special for engineering machinery, different sampling circuits need to be designed for different sensors, and the unification of measuring range and resolution is difficult to achieve. Meanwhile, for an analog quantity voltage output circuit of 0-10V, multiplexing with a resistance sampling circuit is difficult to achieve.
Disclosure of Invention
In view of the above, the present invention provides an analog signal multiplexing circuit and an analog signal acquisition circuit to solve the above problems.
In order to achieve the above purpose, the embodiment of the present invention adopts the following technical solutions:
in a first aspect, an embodiment of the present invention provides an analog signal multiplexing circuit, where the analog signal multiplexing circuit includes a signal input terminal, a voltage-current conversion module, a switch module, and a signal output terminal, the signal input terminal, the voltage-current conversion module, and the signal output terminal are sequentially electrically connected, the switch module is respectively electrically connected to the voltage-current conversion module and the signal output terminal, and the output terminal of the voltage-current conversion module is electrically connected to a load;
the signal output end is used for transmitting the received pulse width modulation signal to the voltage-current conversion module, and the pulse width modulation signal is a voltage signal;
the voltage-current conversion module is used for converting a voltage signal into a current signal, and the current signal is converted into a voltage signal when passing through the load;
when the switch module is in a conducting state, the signal output end outputs a first voltage value, and the first voltage value is a voltage drop value generated when the current signal flows through the load and the switch module;
when the switch module is in a cut-off state, the signal output end outputs a second voltage value, and the second voltage value is a voltage drop value generated when the current signal flows through the load.
Furthermore, the analog signal multiplexing circuit further comprises a signal amplification module, the signal input end and a power supply unit are electrically connected with the input end of the signal amplification module, the output end of the signal amplification module is electrically connected with the voltage-current conversion module, and the signal amplification module is used for amplifying the pulse width modulation signal and transmitting the amplified pulse width modulation signal to the voltage-current conversion module.
Furthermore, the signal amplification module includes a first operational amplifier, a first resistor, a second resistor, a third resistor, a fourth resistor, a fifth resistor, a sixth resistor and a first capacitor, the signal input terminal is electrically connected to the positive input terminal of the first operational amplifier through the second resistor, the signal input terminal is grounded through the first resistor, the power supply unit, the third resistor, the fourth resistor and the inverting input terminal of the first operational amplifier are sequentially connected in series, the inverting input terminal of the first operational amplifier is grounded through the fifth resistor, and the output terminal of the first operational amplifier is electrically connected to the positive input terminal of the first operational amplifier through the sixth resistor.
Furthermore, the analog signal multiplexing circuit further comprises a filtering module, and the signal input end, the filtering module and the voltage-current conversion module are electrically connected in sequence.
Furthermore, the filtering module includes a second operational amplifier, a seventh resistor, an eighth resistor, a ninth resistor, a second capacitor, and a third capacitor, the signal input terminal, the seventh resistor, the eighth resistor, and the positive input terminal of the second operational amplifier are sequentially connected in series, the positive input terminal of the second operational amplifier is grounded through the third capacitor, the output terminal of the second operational amplifier is electrically connected to the seventh resistor and the eighth resistor through the second capacitor, and the output terminal of the second operational amplifier is electrically connected to the negative input terminal of the second operational amplifier through the ninth resistor.
Furthermore, the analog signal multiplexing circuit further comprises an analog input module, an input end of the analog input module is electrically connected with the voltage-current conversion module and the switch module, and an output end of the analog input module is electrically connected with the signal output end.
Further, the analog input module comprises a fourth operational amplifier, a seventeenth resistor, an eighteenth resistor, a nineteenth resistor and a fourth capacitor, the output end of the voltage-current conversion module, the seventeenth resistor and the positive input end of the fourth operational amplifier are sequentially connected in series, the output end of the voltage-current conversion module is sequentially grounded through the seventeenth resistor and the fourth capacitor, the eighteenth resistor is connected in parallel with the fourth capacitor, the output end of the fourth operational amplifier is electrically connected with the inverting input end of the fourth operational amplifier through the nineteenth resistor and is electrically connected with the signal output end,
further, the voltage-current conversion module includes a third operational amplifier, a tenth resistor, an eleventh resistor, a twelfth resistor, a thirteenth resistor, a fourteenth resistor, a fifteenth resistor, and a first switch tube, the tenth resistor is connected in series between the signal input terminal and the non-inverting input terminal of the third operational amplifier, the signal input terminal is electrically connected to the load after being sequentially connected to the tenth resistor and the eleventh resistor in series, the inverting input terminal of the third operational amplifier is grounded through the thirteenth resistor, the output terminal of the third operational amplifier is electrically connected to the base of the first switch tube, the emitter of the first switch tube is electrically connected to the load through the fifteenth resistor, and the emitter of the first switch tube is electrically connected to the inverting input terminal of the third operational amplifier through the twelfth resistor, the collector of the first switch tube is electrically connected with a power supply unit.
Further, the switch module includes a sixteenth resistor and a second switch tube, an output terminal of the voltage-current conversion module is electrically connected to a collector of the second switch tube through the sixteenth resistor, an emitter of the second switch tube is grounded, a base of the second switch tube is electrically connected to a signal input unit, when the base receives a first level signal, the second switch tube is turned on, and when the base receives a second level signal, the second switch tube is turned off.
In a second aspect, an embodiment of the present invention further provides an analog signal collecting circuit, where the analog signal collecting circuit includes a control unit, a signal input unit, an analog-to-digital conversion unit, a storage unit, and an analog signal multiplexing circuit, the control unit is electrically connected to the storage unit, the analog-to-digital conversion unit, and the analog signal multiplexing circuit is electrically connected to the signal input unit and the analog-to-digital conversion unit, the analog signal multiplexing circuit includes a signal input terminal, a voltage-to-current conversion module, a switch module, and a signal output terminal, the signal input terminal, the voltage-to-current conversion module, and the signal output terminal are electrically connected in sequence, the switch module is electrically connected to the voltage-to-current conversion module and the signal output terminal respectively, the output end of the voltage-current conversion module is electrically connected with a load;
the control unit is used for generating a pulse width modulation signal and transmitting the pulse width modulation signal to a signal input end of the analog signal multiplexing circuit;
the signal input unit is used for responding to the operation of a user to generate a turn-on signal or a turn-off signal and transmitting the turn-on signal or the turn-off signal to the analog signal multiplexing circuit;
the analog signal multiplexing circuit is used for outputting a first voltage value or a second voltage value to the analog-to-digital conversion unit according to the conducting signal or the stopping signal, and the first voltage value and the second voltage value are analog signals;
the analog-to-digital conversion unit is used for converting the analog signal into a digital signal;
the control unit is further configured to store a digital signal indicative of the first voltage value or the second voltage value to the storage unit.
The analog signal multiplexing circuit provided by the embodiment of the invention is characterized in that a signal input end, a voltage-current conversion module and a signal output end are sequentially and electrically connected, a switch module is respectively and electrically connected with the voltage-current conversion module and the signal output end, and the output end of the voltage-current conversion module is electrically connected with a load, so that when the switch module is in a conducting state, the signal output end outputs a first voltage value, and when the switch module is in a stopping state, the signal output end outputs a second voltage value; the output state of the switching analog signal multiplexing circuit is achieved by controlling the conduction state of the switch module, when the switch module is in the conduction state, the analog signal multiplexing circuit outputs analog quantity voltage, when the switch module is in the cut-off state, the analog signal multiplexing circuit outputs a load sampling signal, and meanwhile, because the analog signal multiplexing circuit is controlled by the pulse width modulation signal in the sampling process, the effect of adjusting the load measuring range can be achieved by controlling the duty ratio of the pulse width modulation signal, so that the multiplexing of the analog quantity voltage output and the resistance measuring range can be adjusted, the circuit is simplified, and the general degree of a control product is improved.
In order to make the aforementioned and other objects, features and advantages of the present invention comprehensible, preferred embodiments accompanied with figures are described in detail below.
Drawings
In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed to be used in the embodiments will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present invention and therefore should not be considered as limiting the scope, and for those skilled in the art, other related drawings can be obtained according to the drawings without inventive efforts.
Fig. 1 shows a block diagram of a circuit structure of an analog signal acquisition circuit according to an embodiment of the present invention.
Fig. 2 is a block diagram illustrating a circuit structure of an analog signal multiplexing circuit according to an embodiment of the present invention.
Fig. 3 shows a circuit diagram of an analog signal acquisition circuit according to an embodiment of the present invention.
Fig. 4 shows a circuit diagram of a signal amplifying module according to an embodiment of the present invention.
Fig. 5 shows a circuit diagram of a filtering module according to an embodiment of the present invention.
Fig. 6 shows a circuit diagram of a voltage-current conversion module according to an embodiment of the present invention.
Fig. 7 shows a circuit diagram of a switch module provided by an embodiment of the invention.
Fig. 8 shows a circuit diagram of an analog input module according to an embodiment of the present invention.
Icon: 100-an analog signal acquisition circuit; 110-a control unit; 120-analog signal multiplexing circuitry; 121-a signal amplification module; 122-a filtering module; 123-a voltage-current conversion module; 124-a switch module; 125-analog input module; 130-an analog-to-digital conversion unit; 140-a signal input unit; 150-a power supply unit; 160-memory cell.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. The components of embodiments of the present invention generally described and illustrated in the figures herein may be arranged and designed in a wide variety of different configurations.
Thus, the following detailed description of the embodiments of the present invention, presented in the figures, is not intended to limit the scope of the invention, as claimed, but is merely representative of selected embodiments of the invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments of the present invention without making any creative effort, shall fall within the protection scope of the present invention.
It should be noted that: like reference numbers and letters refer to like items in the following figures, and thus, once an item is defined in one figure, it need not be further defined and explained in subsequent figures.
The embodiment of the invention provides an analog signal acquisition circuit 100, which is used for acquiring and processing analog quantity signals for controlling oil level, pressure, temperature and walking action in mechanical equipment. Fig. 1 is a block diagram of a circuit structure of an analog signal acquisition circuit 100 according to an embodiment of the present invention. The analog signal acquisition circuit 100 includes a control unit 110, a signal input unit 140, an analog-to-digital conversion unit 130, a storage unit 160, a power supply unit 150, and an analog signal multiplexing circuit 120. The control unit 110 is electrically connected to the analog-to-digital conversion unit 130, the storage unit 160, the power supply unit 150, and the analog signal multiplexing circuit 120, the analog signal multiplexing circuit 120 is electrically connected to the signal input unit 140, the power supply unit 150, and the analog-to-digital conversion unit 130, and the power supply unit 150 is electrically connected to the analog-to-digital conversion unit 130 and the storage unit 160.
The control unit 110 is used for generating control signals to enable the analog signal acquisition circuit 100 to operate normally and orderly. Specifically, the control unit 110 may be configured to generate a pulse width modulation signal and transmit the pulse width modulation signal to the analog signal multiplexing circuit 120.
In a preferred embodiment, the control unit 110 includes a main control chip, and the model of the control chip is TMS320F 28335.
The analog signal multiplexing circuit 120 is configured to collect an analog signal under the control of the pwm signal, and transmit the collected analog signal to the control unit 110.
Referring to fig. 2, a block diagram of a circuit structure of the analog signal multiplexing circuit 120 according to an embodiment of the present invention is shown. The analog signal multiplexing circuit 120 includes a signal input terminal, a signal amplifying module 121, a filtering module 122, a voltage-current converting module 123, a switching module 124, an analog input module 125, and a signal output terminal. The signal input end, the signal amplification module 121, the filtering module 122, the voltage-current conversion module 123, the analog input module 125 and the signal output end are electrically connected in sequence, and the switch module 124 is electrically connected with the voltage-current conversion module 123 and the signal output end.
The signal input terminal is further electrically connected to the pwm signal output port of the control unit 110, and is configured to transmit the received pwm signal to the signal amplifying module 121.
The input end of the signal amplification module 121 is electrically connected to the signal input end, and the output end of the signal amplification module 121 is electrically connected to the filtering module 122, and is configured to amplify the pulse width modulation signal and transmit the amplified pulse width modulation signal to the voltage-current conversion module 123. Since the pwm signal is usually a small signal, the pwm signal can be properly amplified by the signal amplification module 121, so as to achieve a better acquisition effect.
Referring to fig. 3 and 4, the signal amplifying module 121 includes a first operational amplifier U1, a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, a fifth resistor R5, a sixth resistor R6, and a first capacitor C1, wherein the signal input terminal is electrically connected to the positive input terminal of the first operational amplifier U1 through the second resistor R2, the signal input terminal is grounded through the first resistor R1, the power supply unit 150, the third resistor R3, the fourth resistor R4, and the negative input terminal of the first operational amplifier U1 are sequentially connected in series, the negative input terminal of the first operational amplifier U1 is grounded through the fifth resistor R5, and the output terminal of the first operational amplifier U1 is electrically connected to the positive input terminal of the first operational amplifier U1 through the sixth resistor R6.
The third resistor R3 and the first capacitor C1 form a first RC filter circuit, which can primarily filter interference signals in the pulse width modulation signals; the first operational amplifier U1 and the sixth resistor R6 form a positive feedback hysteresis comparator, which can amplify the PWM signal. In addition, R is6>>R2。
The input end of the filtering module 122 is electrically connected to the output end of the signal amplifying module 121, and the output end of the filtering module 122 is electrically connected to the input end of the voltage-current converting module 123, and is configured to filter interference in the amplified pulse width modulation signal. The filtering module 122 can eliminate interference in the pwm signal, thereby improving the stability of the analog signal multiplexing circuit 120.
Referring to fig. 5, the filter module 122 includes a second operational amplifier U2, a seventh resistor R7, an eighth resistor R8, a ninth resistor R9, a second capacitor C2 and a third capacitor C3, the signal input terminal, the seventh resistor R7, the eighth resistor R8 and the non-inverting input terminal of the second operational amplifier U2 are sequentially connected in series, the non-inverting input terminal of the second operational amplifier U2 is grounded through the third capacitor C3, the output terminal of the second operational amplifier U2 is electrically connected to the seventh resistor R7 and the eighth resistor R8 through the second capacitor C2, and the output terminal of the second operational amplifier U2 is electrically connected to the inverting input terminal of the second operational amplifier U2 through the ninth resistor R9.
The seventh resistor R7 and the second capacitor C2 form a second RC filter circuit, and the eighth resistor R8 and the third capacitor C3 form a third RC filter circuit, which can filter the interference contained in the amplified pwm signal.
The input end of the voltage-current conversion module 123 is electrically connected to the output end of the filtering module 122, the output end of the voltage-current conversion module 123 is electrically connected to the input end of the analog input module 125, and the voltage-current conversion module 123 is configured to convert a voltage signal into a current signal.
Referring to fig. 6, the voltage-current conversion module 123 includes a third operational amplifier U3, a tenth resistor R10, an eleventh resistor R11, and a twelfth resistor R12, a thirteenth resistor R13, a fourteenth resistor R14, a fifteenth resistor R15 and a first switch tube Q1, wherein a tenth resistor R10 is connected in series between the signal input terminal and the non-inverting input terminal of the third operational amplifier U3, the signal input terminal is electrically connected to the load after being sequentially connected in series with a tenth resistor R10 and an eleventh resistor R11, the inverting input terminal of the third operational amplifier U3 is grounded through a thirteenth resistor R13, the output terminal of the third operational amplifier U3 is electrically connected to the base of the first switch tube Q1, the emitter of the first switch tube Q1 is electrically connected to the load through a fifteenth resistor R15, the emitter of the first switch tube Q1 is electrically connected to the inverting input terminal of the third operational amplifier U3 through a twelfth resistor R12, and the collector of the first switch tube Q1 is electrically connected to the power supply unit 150.
The voltage-current conversion module 123 introduces current series negative feedback, thereby implementing voltage-to-current conversion, and can linearly convert the dc voltage signal of the voltage V2 output by the filtering module 122 into a current signal of 0-20 mA. In addition, since the output terminal of the third operational amplifier U3 is electrically connected to both the non-inverting input terminal of the third operational amplifier U3 and the inverting input terminal of the third operational amplifier U3 through the emitter of the first switching tube Q1, that is: both positive and negative feedback are introduced in the voltage-to-current conversion module 123, so that when R is satisfied12/R13＝R10/R11When, I is caused by a reduction in the load RoutIncrease of about equal to I due to positive feedbackoutIs reduced, thus IoutBecomes V2To accomplish the voltage to current conversion. The output current of the voltage-current conversion module 123 can be calculated by the following equation:
Iout＝V2/R15
wherein, IoutIs the output current, V, of the voltage-current conversion module 1232Is the output voltage of the filtering module 122.
The signal input end of the switch module 124 is electrically connected to both the output end of the voltage-current conversion module 123 and the input end of the analog input module 125, and the switch module 124 is further electrically connected to the signal input unit 140 for switching the output state of the analog signal multiplexing circuit 120.
Referring to fig. 7, the switch module 124 includes a sixteenth resistor R16 and a second switch Q2, an output terminal of the voltage-current conversion module 123 is electrically connected to a collector of the second switch Q2 through a sixteenth resistor R16, an emitter of the second switch Q2 is grounded, a base of the second switch Q2 is electrically connected to the signal input unit 140, when the base receives a first level signal, the second switch Q2 is turned on, and when the base receives a second level signal, the second switch Q2 is turned off.
The sixteenth resistor R16 is a current limiting resistor.
In a preferred embodiment, the second switch Q2 is an NPN transistor, and when the signal input port GPIO of the switch module 124 inputs a high-level signal, that is: when GPIO is 1, the second switching tube Q2 is turned on; when the signal input port GPIO port of the switch module 124 inputs a low-level signal, that is: when GPIO is 0, the second switching tube Q2 is turned off.
The input end of the analog input module 125 is electrically connected to the switch module 124 and the output end of the voltage-current conversion module 123, and the output end of the analog input module 125 is electrically connected to the analog-to-digital conversion unit 130, and is configured to transmit the acquired analog signal to the analog-to-digital conversion unit 130.
Referring to fig. 8, the analog input module 125 includes a fourth operational amplifier U4, a seventeenth resistor R17, an eighteenth resistor R18, a nineteenth resistor R19, and a fourth capacitor C4, an output terminal of the voltage-current conversion module 123, a seventeenth resistor R17, and a non-inverting input terminal of the fourth operational amplifier U4 are sequentially connected in series, an output terminal of the voltage-current conversion module 123 is sequentially grounded through the seventeenth resistor R17 and the fourth capacitor C4, an eighteenth resistor R18 is connected in parallel with the fourth capacitor C4, and an output terminal of the fourth operational amplifier U4 is electrically connected to an inverting input terminal of the fourth operational amplifier U4 through the nineteenth resistor R19 and is electrically connected to a signal output terminal.
The analog input module 125 adopts a high-resistance protection mode, and simultaneously comprises a seventeenth resistor R17 and a fourth capacitor C4 to form a fourth RC filter circuit, and an isolation circuit with certain input impedance can effectively prevent large interference signals from inrush.
The analog-to-digital conversion unit 130 is configured to convert the analog signal collected by the analog signal multiplexing circuit 120 into a digital signal, and then transmit the digital signal to the control unit 110.
The storage unit 160 is configured to store the digital signals representing the first voltage value and the second voltage value under the control of the control unit 110.
The signal input unit 140 is used to generate an on signal or an off signal in response to an operation by a user and transmit the on signal or the off signal to the analog signal multiplexing circuit 120.
In the present embodiment, when the signal input unit 140 inputs the turn-on signal, GPIO is 1; when the signal input unit 140 inputs the off signal, GPIO is 0.
The power supply unit 150 is used for supplying power for the analog signal multiplexing circuit 120, the control unit 110, the analog-to-digital conversion unit 130, and the storage unit 160 to operate normally.
The working principle of the invention is as follows:
when the signal input unit 140 inputs the off signal, GPIO is 0, the second switching tube Q2 is turned off, the switching module 124 is disabled, and I is enabled1＝Iout，I20, that is, I1Is determined by the duty cycle of the pulse width modulated signal. Meanwhile, the load end is provided with a resistance sensor, so that the voltage drop value generated after the voltage-current conversion module 123 detects that the current signal flows through the load can be the two ends of the resistance sensorThe analog signal of the pressure value is transmitted to the analog signal sampling port of the control unit 110 after being acted by the analog input module 125 and the analog-to-digital conversion unit 130, the control unit 110 can process the received signal to obtain the size of the load, at this time, the analog signal multiplexing circuit 120 is in a resistance sampling state, the range of the load resistance can be adjusted by adjusting the duty ratio of the pulse width modulation signal, and meanwhile, the measurement precision is 0.5% multiplied by the full range at 25 ℃. The relationship between the range of the load resistor R and the duty ratio of the pulse width modulation signal (PWM) is as follows:
when the signal input unit 140 inputs the on-signal, GPIO is 1, the second switching tube Q2 is turned on, the switching module 124 is enabled, and I is assertedout＝I1+I2At this time, the magnitude of the load resistance in the circuit is determined by the resistance R and the sixteenth resistance R16, and the total load resistance RloadR// R16, the voltage value V at the output of the voltage-to-current conversion module 1233＝Iout*Rload. At this time, the analog signal multiplexing circuit 120 is in an analog voltage output state, and can output a required analog voltage value according to the requirement of a user. Meanwhile, the analog input module 125 is further configured to sample the voltage signal and transmit the sampled voltage signal as a feedback signal to the control unit 110, and the control unit 110 may adjust the magnitude of the analog voltage value in real time by changing the duty ratio of the pulse width modulation signal.
The invention adopts industrial components, can adapt to a stable range of-30-70 ℃, can work in a severe environment, and is suitable for measuring resistance signals and analog quantity voltage output signals in a long distance.
In summary, in the analog signal multiplexing circuit provided in the embodiment of the present invention, the signal input terminal, the voltage-current conversion module and the signal output terminal are sequentially electrically connected, the switch module is electrically connected to the voltage-current conversion module and the signal output terminal respectively, and the output terminal of the voltage-current conversion module is electrically connected to a load, so that when the switch module is in an on state, the signal output terminal outputs a first voltage value, and when the switch module is in an off state, the signal output terminal outputs a second voltage value; the output state of the switching analog signal multiplexing circuit is achieved by controlling the conduction state of the switch module, when the switch module is in the conduction state, the analog signal multiplexing circuit outputs analog quantity voltage, when the switch module is in the cut-off state, the analog signal multiplexing circuit outputs a load sampling signal, and meanwhile, because the analog signal multiplexing circuit is controlled by the pulse width modulation signal in the sampling process, the effect of adjusting the load measuring range can be achieved by controlling the duty ratio of the pulse width modulation signal, so that the multiplexing of the analog quantity voltage output and the resistance measuring range can be adjusted, the circuit is simplified, and the general degree of a control product is improved.
The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention. It should be noted that: like reference numbers and letters refer to like items in the following figures, and thus, once an item is defined in one figure, it need not be further defined and explained in subsequent figures.
Claims (9)
1. An analog signal multiplexing circuit, characterized in that, the analog signal multiplexing circuit includes a signal input terminal, a voltage-current conversion module, a switch module and a signal output terminal, the signal input terminal, the voltage-current conversion module and the signal output terminal are sequentially electrically connected, the switch module is respectively electrically connected with the voltage-current conversion module and the signal output terminal, the output terminal of the voltage-current conversion module is electrically connected with a load, the switch module includes a sixteenth resistor and a second switch tube, the output terminal of the voltage-current conversion module is electrically connected with the collector of the second switch tube through the sixteenth resistor, the emitter of the second switch tube is grounded, the base of the second switch tube is electrically connected with a signal input unit, when the base receives a first level signal, the second switch tube is switched on, and when the base receives a second level signal, the second switch tube is switched off;
the signal input end is used for transmitting a received pulse width modulation signal to the voltage-current conversion module, the pulse width modulation signal is a voltage signal, and the duty ratio of the pulse width modulation signal is adjustable;
the voltage-current conversion module is used for converting a voltage signal into a current signal;
when the second switch tube is in a conducting state, the signal output end outputs a first voltage value, and the first voltage value is a voltage drop value generated when the current signal flows through the load and the switch module;
when the second switch tube is in a cut-off state, the signal output end outputs a second voltage value, and the second voltage value is a voltage drop value generated when the current signal flows through the load.
2. The analog signal multiplexing circuit of claim 1, further comprising a signal amplification module, wherein the signal input terminal and a power supply unit are electrically connected to the input terminal of the signal amplification module, the output terminal of the signal amplification module is electrically connected to the voltage-to-current conversion module, and the signal amplification module is configured to amplify the pwm signal and transmit the amplified pwm signal to the voltage-to-current conversion module.
3. The analog signal multiplexing circuit of claim 2, wherein the signal amplifying module comprises a first operational amplifier, a first resistor, a second resistor, a third resistor, a fourth resistor, a fifth resistor, a sixth resistor, and a first capacitor, the signal input terminal is electrically connected to the non-inverting input terminal of the first operational amplifier through the second resistor, the signal input terminal is grounded through the first resistor, the power supply unit, the third resistor, the fourth resistor, and the inverting input terminal of the first operational amplifier are sequentially connected in series, the inverting input terminal of the first operational amplifier is grounded through the fifth resistor, and the output terminal of the first operational amplifier is electrically connected to the non-inverting input terminal of the first operational amplifier through the sixth resistor.
4. The analog signal multiplexing circuit of claim 1, further comprising a filtering module, wherein the signal input, the filtering module, and the voltage-to-current conversion module are electrically connected in sequence.
5. The analog signal multiplexing circuit of claim 4, wherein the filtering module comprises a second operational amplifier, a seventh resistor, an eighth resistor, a ninth resistor, a second capacitor, and a third capacitor, the signal input terminal, the seventh resistor, the eighth resistor, and the non-inverting input terminal of the second operational amplifier are sequentially connected in series, the non-inverting input terminal of the second operational amplifier is grounded via the third capacitor, the output terminal of the second operational amplifier is electrically connected to the seventh resistor and the eighth resistor via the second capacitor, respectively, and the output terminal of the second operational amplifier is electrically connected to the inverting input terminal of the second operational amplifier via the ninth resistor.
6. The analog signal multiplexing circuit of claim 1, further comprising an analog input module, wherein an input terminal of the analog input module is electrically connected to the voltage-current conversion module and the switch module, and an output terminal of the analog input module is electrically connected to the signal output terminal.
7. The analog signal multiplexing circuit of claim 6, wherein the analog input module comprises a fourth operational amplifier, a seventeenth resistor, an eighteenth resistor, a nineteenth resistor, and a fourth capacitor, the output terminal of the voltage-to-current conversion module, the seventeenth resistor, and the non-inverting input terminal of the fourth operational amplifier are sequentially connected in series, the output terminal of the voltage-to-current conversion module is sequentially connected to ground through the seventeenth resistor and the fourth capacitor, the eighteenth resistor is connected in parallel with the fourth capacitor, and the output terminal of the fourth operational amplifier is electrically connected to the inverting input terminal of the fourth operational amplifier through the nineteenth resistor and is electrically connected to the signal output terminal.
8. The analog signal multiplexing circuit of claim 1, wherein the voltage-to-current conversion module comprises a third operational amplifier, a tenth resistor, an eleventh resistor, a twelfth resistor, a thirteenth resistor, a fourteenth resistor, a fifteenth resistor, and a first switch tube, the tenth resistor is connected in series between the signal input terminal and a non-inverting input terminal of the third operational amplifier, the signal input terminal is electrically connected to the load after being sequentially connected in series with the tenth resistor and the eleventh resistor, an inverting input terminal of the third operational amplifier is grounded through the thirteenth resistor, an output terminal of the third operational amplifier is electrically connected to a base of the first switch tube, an emitter of the first switch tube is electrically connected to the load through the fifteenth resistor, and an emitter of the first switch tube is electrically connected to an inverting input terminal of the third operational amplifier through the twelfth resistor, the collector of the first switch tube is electrically connected with a power supply unit.
9. An analog signal acquisition circuit, characterized in that the analog signal acquisition circuit comprises a control unit, a signal input unit, an analog-to-digital conversion unit, a storage unit and an analog signal multiplexing circuit according to any one of claims 1 to 8, the control unit is electrically connected with the storage unit, the analog-to-digital conversion unit and the analog signal multiplexing circuit, respectively, and the analog signal multiplexing circuit is electrically connected with the signal input unit and the analog-to-digital conversion unit;
the control unit is used for generating a pulse width modulation signal and transmitting the pulse width modulation signal to a signal input end of the analog signal multiplexing circuit;
the signal input unit is used for responding to the operation of a user to generate a turn-on signal or a turn-off signal and transmitting the turn-on signal or the turn-off signal to the analog signal multiplexing circuit;
the analog signal multiplexing circuit is used for outputting a first voltage value or a second voltage value to the analog-to-digital conversion unit according to the conducting signal or the stopping signal, and the first voltage value and the second voltage value are analog signals;
the analog-to-digital conversion unit is used for converting the analog signal into a digital signal;
the control unit is further configured to store a digital signal indicative of the first voltage value or the second voltage value to the storage unit.
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| CN108833790B (en) * | 2018-08-14 | 2021-02-12 | 烟台艾睿光电科技有限公司 | Acquisition circuit, method and device for analog signals |
| CN112798866B (en) * | 2020-12-31 | 2023-05-02 | 江苏中天科技股份有限公司 | Conductivity signal acquisition circuit and testing device |
| CN113691275B (en) * | 2021-09-09 | 2023-07-25 | 苏州汇川控制技术有限公司 | Digital signal transmission circuit and digital signal transmission device |
| CN113899941B (en) * | 2021-09-27 | 2023-08-18 | 湖北航天技术研究院总体设计所 | Current acquisition circuit and acquisition method |
| CN114063551B (en) * | 2021-11-01 | 2024-02-06 | 上海美控智慧建筑有限公司 | Input/output control circuit, controller and air conditioner |
| CN114659545B (en) * | 2022-04-29 | 2024-01-09 | 东风电驱动系统有限公司 | Double-range self-adaptive measurement method and device |
| CN114636672B (en) * | 2022-05-11 | 2022-09-06 | 之江实验室 | Photoacoustic and ultrasonic multiplexing acquisition system and method |
| CN114815720B (en) * | 2022-06-29 | 2022-09-09 | 天津飞旋科技股份有限公司 | Programmable controller, analog quantity multiplexing interface control method thereof and storage medium |
| CN115514194B (en) * | 2022-11-24 | 2023-02-28 | 成都市易冲半导体有限公司 | Load resistance value determining method and device, electronic equipment and storage medium |
| CN116094512B (en) * | 2023-02-01 | 2023-12-12 | 无锡宇宁智能科技有限公司 | Analog direct addition circuit and corresponding electronic equipment |
| CN117424598B (en) * | 2023-12-15 | 2024-03-29 | 浙江国利信安科技有限公司 | Device for outputting analog quantity |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105247789A (en) * | 2013-06-28 | 2016-01-13 | 英特尔公司 | Pulse width modular for voltage regulator |
| DE102015009245A1 (en) * | 2015-07-17 | 2017-01-19 | Infineon Technologies Ag | METHOD AND DEVICE FOR PREPARING A CUSTOMIZABLE HIGH RESOLUTION TIME |
| CN206164508U (en) * | 2016-11-17 | 2017-05-10 | 广州派高智能科技有限公司 | Pilot lamp and multiplexing port control's of button circuit |
| CN107340466A (en) * | 2016-04-28 | 2017-11-10 | 中芯国际集成电路制造(上海)有限公司 | Analog signal detection system and analog signal detection method |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| TWI445442B (en) * | 2011-08-23 | 2014-07-11 | Luxmill Electronic Co Ltd | Lighting module with a sampling and integrating circuit for pwm dimming apparatus |
-
2017
- 2017-11-17 CN CN201711142835.0A patent/CN107942787B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105247789A (en) * | 2013-06-28 | 2016-01-13 | 英特尔公司 | Pulse width modular for voltage regulator |
| DE102015009245A1 (en) * | 2015-07-17 | 2017-01-19 | Infineon Technologies Ag | METHOD AND DEVICE FOR PREPARING A CUSTOMIZABLE HIGH RESOLUTION TIME |
| CN107340466A (en) * | 2016-04-28 | 2017-11-10 | 中芯国际集成电路制造(上海)有限公司 | Analog signal detection system and analog signal detection method |
| CN206164508U (en) * | 2016-11-17 | 2017-05-10 | 广州派高智能科技有限公司 | Pilot lamp and multiplexing port control's of button circuit |
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