CN202257335U - Voltage and current output device - Google Patents
Voltage and current output device Download PDFInfo
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- CN202257335U CN202257335U CN2011203438096U CN201120343809U CN202257335U CN 202257335 U CN202257335 U CN 202257335U CN 2011203438096 U CN2011203438096 U CN 2011203438096U CN 201120343809 U CN201120343809 U CN 201120343809U CN 202257335 U CN202257335 U CN 202257335U
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Abstract
The utility model discloses a voltage and current output device which comprises a reference voltage generator, a main controller, a digital to analog converter respectively connected with the reference voltage generator and the main controller, and a voltage and current converting circuit respectively connected with the reference voltage generator, the main controller and the digital to analog converter and used for selecting voltage output or current output according to control signals sent by the main controller. As a voltage amplifying circuit and a current output circuit are integrated in one circuit structure, random switching of the voltage output and current output can be realized through a negative feedback principle of an operational amplifier and by switching different feedback points, programmable voltage or programmable current can be output in the same port, various voltage or current ranges can be realized, the structure is simple and the realization cost is low.
Description
Technical field
The utility model relates to the electric current and voltage export technique field of PLC (programmable logic controller (PLC)) control system and instrument and meter, in particular a kind of programmable voltage/current output circuit.
Background technology
At the frequent working voltage current signal of industry spot control actuating equipment, often need uses-10V ~+10V voltage signal or 0 ~ 20mA, 4 ~ 20mA current signal passes through the Frequency Converter Control rotating speed of motor; Rotating; Start, stop to wait operation, or the switch motion of control ratio solenoid valve.
And most of instrument can only realize single range output in the prior art; Voltage output or electric current output; If can output voltage again can output current, then need use inconvenience like this through different connection terminal output; Need take 2 times connection terminal, thereby increase the volume of product.
Also have through relay and come the mode of switched voltage and electric current output multiplexing, but the relay contact limited service life.The quantity of the precision operational-amplifier that uses is also more, and then cost can increase.
Therefore, prior art awaits to improve and development.
The utility model content
In view of the deficiency of above-mentioned prior art, the purpose of the utility model is to provide a kind of electric current and voltage output unit, can realize the generation of needed voltage of industry spot or current signal, and simple in structure, realizes that cost is low.
The technical scheme of the utility model is following:
A kind of electric current and voltage output unit wherein, comprising:
Pedestal generator;
Master controller;
The digital to analog converter that is connected with pedestal generator, master controller respectively;
And be connected with pedestal generator, master controller, digital to analog converter respectively, be used for the control signal sent according to master controller, select the voltage current transformating circuit of voltage output or electric current output.
Described electric current and voltage output unit; Wherein, Said voltage current transformating circuit comprises the first operational amplifier U1 and the second operational amplifier U2; The reverse input end of the said first operational amplifier U1 is connected to principal voltage input end Vin through the input end in the same way that first resistance R 1 connects reference voltage input VREF, the said first operational amplifier U1 through the 5th resistance R 5, and the output terminal of the said first operational amplifier U1 is connected to the first output terminal V/I out through the 3rd resistance R 3 and the 4th resistance R s successively;
Said second operational amplifier U2 input end in the same way is connected to forward voltage feedback end Sense+ through the 9th resistance R 9, and the said second operational amplifier U2 reverse input end is connected to the feedback output end of the said second operational amplifier U2 through the tenth resistance R 10;
The reverse input end of the said first operational amplifier U1 also is connected to the common port that the 3rd resistance R 3 is connected with the 4th resistance R s through second resistance R 2 and first switch S 1 successively; The common port that said second resistance R 2 is connected with first switch S 1 is connected to the feedback output end of the said second operational amplifier U2 successively through the 7th resistance R 7 and second switch S2;
The input end in the same way of the said first operational amplifier U1 also is connected to the feedback output end of the said second operational amplifier U2 successively through the 8th resistance R 8 and the 3rd switch S 3;
The common port that said the 8th resistance R 8 is connected with the 3rd switch S 3; Be connected to ground connection output terminal GND through the 11 resistance R 11, the 4th switch S the 4, the 12 resistance R 12 successively, the common port that said the 4th switch S 4 is connected with the 12 resistance R 12 also is connected to negative voltage feedback end Sense-.
Described electric current and voltage output unit, wherein, the said first output terminal V/I out also is connected with forward voltage feedback end Sense+ through the 6th resistance R 6.
Described electric current and voltage output unit, wherein, said second operational amplifier U2 input end in the same way also is connected to the common port that said the 4th switch S 4 is connected with the 12 resistance R 12 through first capacitor C 1.
Described electric current and voltage output unit; Wherein, Said voltage current transformating circuit also comprises: the first triode T1 and the second triode T2, and the base stage of the base stage of the said first triode T1 and the second triode T2 is connected to the output terminal of the said first operational amplifier U1 jointly;
The emitter of the emitter of the said first triode T1 and the second triode T2 is connected to the common port that the 3rd resistance R 3 is connected with the 4th resistance R s jointly;
The collector of the said first triode T1 is connected to first working power anode+AV; The collector of the said second triode T2 is connected to the negative terminal-AV of first working power.
The electric current and voltage output unit that the utility model provided is incorporated into voltage amplifier circuit and current output circuit in the circuit structure, through the negative-feedback principle of operational amplifier owing to adopt; Through switching different feedback points; Can realize electric current and voltage output switching arbitrarily, can be implemented in and realize programmable voltage or programmable current output on the same port, and can realize multiple voltage or current range; Can realize+/-10V, 0 ~ 10V, 0 ~ 5V ,+/-5V, 0 ~ 20mA, 4 ~ 20mA ,+/-free voltage or current ranges such as 20mA; The connection terminal quantity of product be can practice thrift, can needs output voltage or current signal be neatly used according to the scene, and simple in structure; The realization cost is low, manipulates flexible.
Description of drawings
Fig. 1 is the electric current and voltage output unit structural representation of the utility model embodiment.
Fig. 2 is the voltage current transformating circuit structural representation of the utility model embodiment.
Fig. 3 is the equivalent circuit structure figure of voltage current transformating circuit when the voltage output mode of the utility model embodiment.
Fig. 4 is the equivalent circuit structure figure of voltage current transformating circuit when the electric current output mode of the utility model embodiment.
Fig. 5 is that the voltage current transformating circuit of the utility model embodiment has added the structural representation when protecting diode.
Embodiment
The utility model provides a kind of electric current and voltage output unit, for purpose, technical scheme and the effect that makes the utility model is clearer, clear and definite, below with reference to accompanying drawing and give an actual example to the utility model further explain.Should be appreciated that specific embodiment described herein only in order to explanation the utility model, and be not used in qualification the utility model.
A kind of electric current and voltage output unit of the utility model embodiment, as shown in Figure 1, mainly comprise:
Be used to produce the pedestal generator 130 of reference voltage;
Be used for the master controller 110 that main control is used;
The digital to analog converter 120 that is connected with pedestal generator 130, master controller 110 respectively;
And 120 that be connected with pedestal generator 130, master controller 110, digital to analog converter respectively, be used for the control signal sent according to master controller 110, select the voltage current transformating circuit 150 of voltage output or electric current output.Voltage current transformating circuit 150 is output voltage or electric current to load 200 as required.
In the present embodiment, can realize+/-10V with+/-20mA range (from then on other range can be got in two ranges) when output, adopt reference voltage V REF=2.5V, digital to analog converter DAC output voltage range is 0 ~ 5V.
Wherein as shown in Figure 2; Said voltage current transformating circuit 150 comprises the first operational amplifier U1 and the second operational amplifier U2; The reverse input end of the said first operational amplifier U1 is connected to principal voltage input end Vin through the input end in the same way that first resistance R 1 connects reference voltage input VREF, the said first operational amplifier U1 through the 5th resistance R 5, and the output terminal of the said first operational amplifier U1 is connected to the first output terminal V/I out through the 3rd resistance R 3 and the 4th resistance R s successively.
Said second operational amplifier U2 input end in the same way is connected to forward voltage feedback end Sense+ through the 9th resistance R 9, and the said second operational amplifier U2 reverse input end is connected to the feedback output end of the said second operational amplifier U2 through the tenth resistance R 10.
The reverse input end of the said first operational amplifier U1 also is connected to the common port that the 3rd resistance R 3 is connected with the 4th resistance R s through second resistance R 2 and first switch S 1 successively; The common port that said second resistance R 2 is connected with first switch S 1 is connected to the feedback output end of the said second operational amplifier U2 successively through the 7th resistance R 7 and second switch S2.
The input end in the same way of the said first operational amplifier U1 also is connected to the feedback output end of the said second operational amplifier U2 successively through the 8th resistance R 8 and the 3rd switch S 3.
The common port that said the 8th resistance R 8 is connected with the 3rd switch S 3; Be connected to ground connection output terminal GND through the 11 resistance R 11, the 4th switch S the 4, the 12 resistance R 12 successively, the common port that said the 4th switch S 4 is connected with the 12 resistance R 12 also is connected to negative voltage feedback end Sense-.
Described electric current and voltage output unit, wherein, the said first output terminal V/I out also is connected with forward voltage feedback end Sense+ through the 6th resistance R 6.
Wherein, the said second operational amplifier U2 in the same way input end also be connected to the common port that said the 4th switch S 4 is connected with the 12 resistance R 12 through first capacitor C 1.
Wherein, said voltage current transformating circuit also comprises: the first triode T1 and the second triode T2, and the base stage of the base stage of the said first triode T1 and the second triode T2 is connected to the output terminal of the said first operational amplifier U1 jointly;
The emitter of the emitter of the said first triode T1 and the second triode T2 is connected to the common port that the 3rd resistance R 3 is connected with the 4th resistance R s jointly;
The collector of the said first triode T1 is connected to first working power anode+AV; The collector of the said second triode T2 is connected to the negative terminal-AV of first working power.
The second operational amplifier U2 carries out impedance conversion as follower among the utility model embodiment, because the output driving current of the first operational amplifier U1 is limited, so increase the one-level power driving circuit.This power driving circuit is as shown in Figure 2: be made up of the pliotron first triode T1 and the second triode T2 and biasing resistor the 3rd resistance R 3.
The electric current and voltage output unit of the utility model embodiment can automatically switch to voltage output mode or electric current output mode.
As shown in Figure 2, the 4th resistance R s is the sampling resistor of constant current source output able to programme in the present embodiment, and it is little to require the precision resistance temperature to float.
Referring to Fig. 2, when the voltage output mode: first switch S 1 and the 3rd switch S 3 are broken off; Second switch S2 and the 4th switch S 4 short circuits are closed.Form voltage output mode equivalent electrical circuit as shown in Figure 3, forward voltage feedback end Sense+ and negative voltage feedback end Sense-are connected on the two ends of pull-up resistor RL, and the voltage on the collection pull-up resistor RL remains unchanged it and do not receive the influence of cloth line resistance:
Voltage output mode equivalent electrical circuit as shown in Figure 3:
The condition R1=R5=a*R of coupling; R2=R8=b*R; R7=R11=c*R; Voltage VL on the pull-up resistor RL=(* of Vin-VREF) (b+c)/a.
Then voltage is output as under the voltage output mode:
CMRR (common-mode rejection ratio) condition is:
With reference to figure 2, when the electric current output mode: first switch S 1 and the 3rd switch S 3 short circuits are closed; Second switch S2 and the 4th switch S 4 are broken off; Its electric current output equivalent circuit is as shown in Figure 4.Wherein: matching condition R1=R5=a*R; R2=R8=b*R; Electric current I L on constant current source sampling resistor the 4th resistance R s and the pull-up resistor RL=(* b/(a * Rs) of Vin-VREF).
Output current is:
(1.3)
CMRR condition:
(1.4).
Switch (S1 ~ S4 can be relay or electronic switch) different feedback resistance through 4 switches among the utility model embodiment and realize voltage output and electric current output function.Feedback end is load RL during voltage output, and feedback end is sampling resistor the 4th resistance R s during constant current output.
Among the utility model embodiment, can realize+/-10V with+/-20mA range (from then on other range can be got in two ranges) when output, reference voltage V REF=2.5V, digital to analog converter DAC output voltage range is 0 ~ 5V, can adopt R1=R5=30K; R2=R8=6K; R7=R11=114K, Rs=25 Ω.
During the voltage output mode, with reference to figure 3:
Vout?=?（Vin?-?Vref）*?（R2?+?R7）/?R1
=?（Vin?-?2.5V）*?(114KΩ?+?6KΩ)/30KΩ
=(the * 4 of Vin-2.5V); Wherein, Vin=0 ~ 5V; When then drawing the voltage output mode of present embodiment, output voltage V out is+/-the 10V output area.
During the electric current output mode, with reference to figure 4:Iout=(* R2/(R1 * Rs) of Vin-Vref)
=?（Vin?-?2.5V）*?6KΩ?/?(?30KΩ?*?25Ω)
= （Vin?-?2.5V）/125Ω。
When then drawing present embodiment electric current output mode, output current Iout is+/-the 20mA output area.
Avoid external voltage to destroy elements such as amplifier in order to make protection output terminal and feedback end; Can on output port, increase the protection diode; As shown in Figure 5, will protect diode D1, D2, D3 to be separately positioned on the first output terminal V/I out, forward voltage feedback end Sense+ and the negative voltage feedback end Sense-.
In sum, the electric current and voltage output unit that the utility model provided is incorporated into voltage amplifier circuit and current output circuit in the circuit structure owing to adopt; Through the negative-feedback principle of operational amplifier,, can realize electric current and voltage output switching arbitrarily through switching different feedback points; Can be implemented in and realize programmable voltage or programmable current output on the same port; And can realize multiple voltage or current range, can realize+/-10V, 0 ~ 10V, 0 ~ 5V ,+/-5V, 0 ~ 20mA, 4 ~ 20mA ,+/-free voltage or current ranges such as 20mA, the connection terminal quantity that can practice thrift product; Can use needs output voltage or current signal neatly according to the scene; And simple in structure, realize that cost is low, manipulate flexible.
Should be understood that; The application of the utility model is not limited to above-mentioned giving an example; Concerning those of ordinary skills, can improve or conversion according to above-mentioned explanation, all these improvement and conversion all should belong to the protection domain of the utility model accompanying claims.
Claims (5)
1. an electric current and voltage output unit is characterized in that, comprising:
Pedestal generator;
Master controller;
The digital to analog converter that is connected with pedestal generator, master controller respectively;
And be connected with pedestal generator, master controller, digital to analog converter respectively, be used for the control signal sent according to master controller, select the voltage current transformating circuit of voltage output or electric current output.
2. electric current and voltage output unit according to claim 1; It is characterized in that; Said voltage current transformating circuit comprises: first operational amplifier (U1) and second operational amplifier (U2); The reverse input end of said first operational amplifier (U1) is connected to principal voltage input end (Vin) through the input end in the same way that first resistance (R1) connects reference voltage input (VREF), said first operational amplifier (U1) through the 5th resistance (R5), and the output terminal of said first operational amplifier (U1) is connected to first output terminal (V/I out) through the 3rd resistance (R3) and the 4th resistance (Rs) successively;
Said second operational amplifier (U2) input end in the same way is connected to forward voltage feedback end (Sense+) through the 9th resistance (R9), and said second operational amplifier (U2) reverse input end is connected to the feedback output end of said second operational amplifier (U2) through the tenth resistance (R10);
The reverse input end of said first operational amplifier (U1) also is connected to the common port that the 3rd resistance (R3) is connected with the 4th resistance (Rs) through second resistance (R2) and first switch (S1) successively; The common port that said second resistance (R2) is connected with first switch (S1) is connected to the feedback output end of said second operational amplifier (U2) successively through the 7th resistance (R7) and second switch (S2);
The input end in the same way of said first operational amplifier (U1) also is connected to the feedback output end of said second operational amplifier (U2) successively through the 8th resistance (R8) and the 3rd switch (S3);
The common port that said the 8th resistance (R8) is connected with the 3rd switch (S3); Be connected to ground connection output terminal (GND) through the 11 resistance (R11), the 4th switch (S4), the 12 resistance (R12) successively, the common port that said the 4th switch (S4) is connected with the 12 resistance (R12) also is connected to negative voltage feedback end (Sense-).
3. electric current and voltage output unit according to claim 2 is characterized in that, said first output terminal (V/I out) also is connected with forward voltage feedback end (Sense+) through the 6th resistance (R6).
4. electric current and voltage output unit according to claim 2; It is characterized in that said second operational amplifier (U2) input end in the same way also is connected to the common port that said the 4th switch (S4) is connected with the 12 resistance (R12) through first electric capacity (C1).
5. electric current and voltage output unit according to claim 2; It is characterized in that; Said voltage current transformating circuit also comprises: first triode (T1) and second triode (T2), and the base stage of the base stage of said first triode (T1) and second triode (T2) is connected to the output terminal of said first operational amplifier (U1) jointly;
The emitter of the emitter of said first triode (T1) and second triode (T2) is connected to the common port that the 3rd resistance (R3) is connected with the 4th resistance (Rs) jointly;
The collector of said first triode (T1) be connected to the first working power anode (+AV); The negative terminal that the collector of said second triode (T2) is connected to first working power (AV).
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2011203438096U CN202257335U (en) | 2011-09-14 | 2011-09-14 | Voltage and current output device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2011203438096U CN202257335U (en) | 2011-09-14 | 2011-09-14 | Voltage and current output device |
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| CN202257335U true CN202257335U (en) | 2012-05-30 |
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| CN2011203438096U Expired - Fee Related CN202257335U (en) | 2011-09-14 | 2011-09-14 | Voltage and current output device |
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Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103922444A (en) * | 2013-01-10 | 2014-07-16 | 阿索特·帕比科文西·哈恰特良 | Circuit and device for electrolytic activation of water-containing substance |
| CN105704072A (en) * | 2014-12-16 | 2016-06-22 | 联发科技股份有限公司 | Line driver with active termination and associated method |
| WO2022090475A1 (en) * | 2020-10-30 | 2022-05-05 | Analog Devices International Unlimited Company | Dac with configurable output stage |
| CN116388763A (en) * | 2023-04-10 | 2023-07-04 | 苏州领慧立芯科技有限公司 | DAC compatible with voltage/current output |
| CN117411488A (en) * | 2023-12-11 | 2024-01-16 | 杭州晶华微电子股份有限公司 | Digital-to-analog conversion circuit with dual-mode output and digital-to-analog conversion chip |
-
2011
- 2011-09-14 CN CN2011203438096U patent/CN202257335U/en not_active Expired - Fee Related
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103922444A (en) * | 2013-01-10 | 2014-07-16 | 阿索特·帕比科文西·哈恰特良 | Circuit and device for electrolytic activation of water-containing substance |
| CN103922444B (en) * | 2013-01-10 | 2016-02-03 | 阿索特·帕比科文西·哈恰特良 | A kind of circuit for electrolytic activation hydrous matter and device |
| CN105704072A (en) * | 2014-12-16 | 2016-06-22 | 联发科技股份有限公司 | Line driver with active termination and associated method |
| WO2022090475A1 (en) * | 2020-10-30 | 2022-05-05 | Analog Devices International Unlimited Company | Dac with configurable output stage |
| CN116388763A (en) * | 2023-04-10 | 2023-07-04 | 苏州领慧立芯科技有限公司 | DAC compatible with voltage/current output |
| CN116388763B (en) * | 2023-04-10 | 2023-12-22 | 苏州领慧立芯科技有限公司 | DAC compatible with voltage/current output |
| CN117411488A (en) * | 2023-12-11 | 2024-01-16 | 杭州晶华微电子股份有限公司 | Digital-to-analog conversion circuit with dual-mode output and digital-to-analog conversion chip |
| CN117411488B (en) * | 2023-12-11 | 2024-03-26 | 杭州晶华微电子股份有限公司 | Digital-to-analog conversion circuit with dual-mode output and digital-to-analog conversion chip |
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| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20120530 Termination date: 20180914 |
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| CF01 | Termination of patent right due to non-payment of annual fee |