CN201335856Y - Voltage-current converting circuit - Google Patents
Voltage-current converting circuit Download PDFInfo
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- CN201335856Y CN201335856Y CNU2008202086064U CN200820208606U CN201335856Y CN 201335856 Y CN201335856 Y CN 201335856Y CN U2008202086064 U CNU2008202086064 U CN U2008202086064U CN 200820208606 U CN200820208606 U CN 200820208606U CN 201335856 Y CN201335856 Y CN 201335856Y
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Abstract
The utility model provides a voltage-current converting circuit, which comprises an amplifier. Input voltage is input to the cophase input end of the amplifier; and the reverse input end of the amplifier is grounded. The voltage-current converting circuit is characterized in that the output end of the amplifier is connected with the base electrode of a Darlington circuit; a first resistor is in bridge connection between the cophase input end of the amplifier and the collector electrode of the Darlington circuit; a second resistor is in bridge connection between the inverting input end of the amplifier and the positive electrode of the power supply; a third resistor is connected between the second resistor and the first resistor; and the emitter of the Darlington circuit is grounded through a fourth resistor. The utility model has the advantages of high accuracy, good thermal stability, linearity and interference immunity, and stable and reliable working performance; a plurality of the voltage-current converting circuits can be connected to a voltage reference point (common ground) simultaneously, and are measured and transmitted simultaneously; and the voltage-current converting circuit achieve the common-ground circulation detection of multichannel fault signals, and has high cost performance, simple circuit and easy implementation.
Description
Technical field
The utility model relates to a kind of voltage current transformating circuit, be used for becoming in the various pick-up units such as the phase shortage of sending class instrument and high voltage transducer power unit, overvoltage, under-voltage, device overcurrent, optical fiber open circuit, unit excess temperature, belong to the voltage current transformating circuit technical field.
Background technology
In present unit series connection type high voltage converter technique scheme, the relatively independent work of each power cell is subjected to electricity after overcommutation, filtering, auxiliary power start, accept process such as control signal, enters normal frequency conversion, output power again.In the course of normal operation, cell controller needs the various failure messages of active detecting, as input phase shortage, overvoltage, under-voltage, device overcurrent, optical fiber open circuit, unit excess temperature etc., and in time judge and handle and report main control unit.
When cell controller detects various failure message, must handle various fault-signals.For improving interference free performance, especially transmit for long range signals, adopt the voltage-to-current switch technology usually, marking current is become send output, the change of output send electric current to produce pressure drop through a pull-up resistor, and this pressure drop is then imported as the sampling of next stage amplifier signal voltage.
Common voltage to current converter mostly is the load ground connection type on as shown in Figure 1 the floating ground of load type, the floating ground of input as shown in Figure 2 or input as shown in Figure 3, the out of phase load ground connection type of output.Floating ground of load type voltage to current converter comprises inverting amplifier N1, the in-phase input end of inverting amplifier N1 connects input voltage Vi1, the inverting input of inverting amplifier N1 is by resistance R 1 ground connection, and the output terminal of inverting amplifier N1 connects resistance R 1 by resistance R L1.The load ground connection type voltage to current converter on the floating ground of input comprises inverting amplifier N2, the output terminal of the direct-connected inverting amplifier N2 of the inverting input of inverting amplifier N2, the electrode of input voltage Vi2 connects the in-phase input end of inverting amplifier N2, another electrode of input voltage Vi2 is by resistance R L2 ground connection, and the output terminal of inverting amplifier N2 connects resistance R L2 by resistance R 2.Input, the out of phase load ground connection type voltage to current converter of output comprise inverting amplifier N3, input voltage Vi3 connects the reverse input end of inverting amplifier N3 by resistance R 3, cross-over connection resistance R 5 between the reverse input end of inverting amplifier N3 and the output terminal, the output terminal of inverting amplifier N3 is by the resistance R 6 and the resistance R L3 ground connection of series connection, and the input end in the same way of inverting amplifier N3 is by between resistance R 4 connections and resistance R 6 and the resistance R L3.
If adopt many voltage-to-current conversion modules simultaneously the reference point of input signal and output signal to be inserted same voltage reference points (altogether), measure simultaneously and change is sent, being the voltage to current converter that can not directly adopt the floating ground of load type, also is the load ground connection type voltage to current converter that can not directly adopt input floating ground.Because as shown in Figure 1, because the negative signal end ground connection of resistance R L1, can cause resistance R 1 shorted to earth, and resistance R 1 is the key of scale-up factor among the determining function Io1=Vi1/R1, Io1 is the electric current on the resistance R L1, just can find out from this mathematical model, if R1=0, Io1=∞ then, circuit just can't operate as normal; As shown in Figure 2 the pull-up resistor RL2 shorted to earth because the Voltage Reference of Vi2 is named a person for a particular job, at this moment the electric current I o2 on the RL2 all over the ground along separate routes, in fact at this moment the positive signal end of resistance R L2 is exactly, so also just do not have electric current to export in this point.
Touring detection for multiple signals, detect the same together, can not directly adopt the load ground connection type voltage to current converter on the voltage to current converter of the floating ground of load type or the floating ground of input, if will adopt the voltage to current converter of floating ground of load type or the load ground connection type voltage to current converter on the floating ground of input, must increase other circuit arrangement so, this just makes the circuit structure complexity; If adopt input, the out of phase load ground connection type voltage to current converter of output, as shown in Figure 3, because the direction of the electric current I o3 on the resistance R L3 is just in time opposite with the direction of Vi3, so detecting the loop, each all to increase an inverting amplifier, also will make circuit complicated.
The utility model content
The purpose of this utility model provides that a kind of circuit structure is simple, function admirable and be practical can the satisfying input, output signal and can satisfy input, load ground connection type voltage-to-current translation circuit that output phase is identical altogether again of touring detection.
In order to achieve the above object, the technical solution of the utility model has provided a kind of voltage-to-current translation circuit, comprise amplifier, input voltage connects the in-phase input end of amplifier, the reverse input end ground connection of amplifier, it is characterized in that, the output terminal of amplifier connects the base stage of Darlington circuit, cross-over connection first resistance between the collector of the in-phase input end of amplifier and Darlington circuit, cross-over connection second resistance between the positive pole of amplifier's inverting input and power supply, be connected the 3rd resistance between second resistance and first resistance, the emitter-base bandgap grading of Darlington circuit is by the 4th resistance eutral grounding.
Because output stage adopts Darlington circuit, then the power consumption of amplifier is very little, makes that the work of amplifier is very reliable and stable, and especially thermal stability is good especially, therefore can also increase considerably effective output.
By this circuit as can be known, the utlity model has following advantage: the accuracy height; Heat stability is good; Good linearity; Anti-interference is good; Stable and reliable working performance; Many voltage-to-current translation circuits of the present utility model can insert a voltage reference points (altogether) simultaneously, measure simultaneously and change is sent; Realization for the multichannel fault-signal go the rounds commonly detect; Ratio of performance to price height; Circuit is simple, realizes easily.
Description of drawings
Fig. 1 is the electrical schematic diagram of floating ground of load type voltage to current converter;
Fig. 2 is the electrical schematic diagram of the load ground connection type voltage to current converter on the floating ground of input;
Fig. 3 is the electrical schematic diagram of input, the out of phase load ground connection type voltage to current converter of output;
The electrical schematic diagram of a kind of voltage-to-current translation circuit that Fig. 4 provides for the utility model.
Embodiment
Specify the utility model below in conjunction with embodiment.
Embodiment
As shown in Figure 4, the electrical schematic diagram of a kind of voltage-to-current translation circuit that provides for the utility model is made up of amplifier N4, first resistance R 10, second resistance R 9, the 3rd resistance R c, the 4th resistance R L4, the 5th resistance R 7, the 6th resistance R 8, the first Darlington transistor V1 and the second Darlington transistor V2.
Input voltage Vi4 connects the in-phase input end of amplifier N4 by the 5th resistance R 7, the reverse input end of amplifier N4 is by the 6th resistance R 8 ground connection, the output terminal of amplifier N4 connects the base stage of Darlington circuit, Darlington circuit is made up of the first Darlington transistor V1 and the second Darlington transistor V2, cross-over connection first resistance R 10 between the collector of the in-phase input end of amplifier N4 and Darlington circuit, cross-over connection second resistance R 9 between the positive pole of the inverting input of amplifier N4 and power supply E, be connected the 3rd resistance R c between second resistance R 9 and first resistance R 10, the emitter-base bandgap grading of Darlington circuit is by the 4th resistance R L4 ground connection.
Output current Io4=Vi4/Rc on the 4th resistance R L4 that obtains by this circuit, this relational expression can be derived through the following steps and be drawn:
Making the pressure drop on the amplifier N4 in-phase input end is Va, and the pressure drop on the amplifier N4 inverting input is Vb, and the pressure drop on the first Darlington transistor V1 and the second Darlington transistor V2 is respectively Vo
Make R7=R8=R9=R10,
Va=E[R8/ (R8+R9) then]=E/2, Vb=(Vo+Vi4) [R7/ (R7+R10)]=(Vo+Vi4)/2
∵Va＝Vb，
∴E/2＝(Vo+Vi4)/2，
∴E＝Vo+Vi4
∵ E=Vo+IcRc again,
∴Vo+IcRc＝Vo+Vi4，
∴IcRc＝Vi4，
∴Ic＝Vi4/Rc，
∵Ic＝αIo4，
∴αIo4＝Vi4/Rc，
∴Io4＝Vi4/αRc，
Conclusion: Io4=Vi4/Rc (because β=β 1 β 2 of Darlington transistor is very big, ∴ α approaches 1, so make α=1, draws above-mentioned conclusion) is that Io is the direct proportion function of Vi4, and 1/Rc is a scale-up factor.In the formula, α=β/(1+ β), α is the common base short circuit current amplification fact, β is the common emitter short circuit current amplification fact.
Claims (1)
1. voltage-to-current translation circuit, comprise amplifier (N4), input voltage (Vi4) connects the in-phase input end of amplifier (N4), the reverse input end ground connection of amplifier (N4), it is characterized in that, the output terminal of amplifier (N4) connects the base stage of Darlington circuit, cross-over connection first resistance (R10) between the collector of the in-phase input end of amplifier (N4) and Darlington circuit, cross-over connection second resistance (R9) between the positive pole of the inverting input of amplifier (N4) and power supply (E), be connected the 3rd resistance (Rc) between second resistance (R9) and first resistance (R10), the emitter-base bandgap grading of Darlington circuit is by the 4th resistance (RL4) ground connection.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNU2008202086064U CN201335856Y (en) | 2008-12-30 | 2008-12-30 | Voltage-current converting circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNU2008202086064U CN201335856Y (en) | 2008-12-30 | 2008-12-30 | Voltage-current converting circuit |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN201335856Y true CN201335856Y (en) | 2009-10-28 |
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CNU2008202086064U Expired - Fee Related CN201335856Y (en) | 2008-12-30 | 2008-12-30 | Voltage-current converting circuit |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN201335856Y (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101551938B (en) * | 2008-12-30 | 2010-12-01 | 上海科达机电控制有限公司 | Voltage-current transformation method |
| CN102768554A (en) * | 2012-07-23 | 2012-11-07 | 中国兵器工业集团第二一四研究所苏州研发中心 | Constant-current source for gyroscope gauge outfit torquer |
-
2008
- 2008-12-30 CN CNU2008202086064U patent/CN201335856Y/en not_active Expired - Fee Related
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101551938B (en) * | 2008-12-30 | 2010-12-01 | 上海科达机电控制有限公司 | Voltage-current transformation method |
| CN102768554A (en) * | 2012-07-23 | 2012-11-07 | 中国兵器工业集团第二一四研究所苏州研发中心 | Constant-current source for gyroscope gauge outfit torquer |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| C17 | Cessation of patent right | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20091028 Termination date: 20131230 |