CN203745514U - Broadband linear voltage isolator - Google Patents
Broadband linear voltage isolator Download PDFInfo
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- CN203745514U CN203745514U CN201420120479.8U CN201420120479U CN203745514U CN 203745514 U CN203745514 U CN 203745514U CN 201420120479 U CN201420120479 U CN 201420120479U CN 203745514 U CN203745514 U CN 203745514U
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Abstract
The utility model discloses a broadband linear voltage isolator, comprising an input voltage dividing/protecting circuit, a difference input/power amplification circuit, and an isolation/null shift compensating circuit, which are connected in order. The broadband linear voltage isolator adopts a LA25-NP type Hall element as a blocking device. The broadband linear voltage isolator is advantageous in that after the input voltage is divided by a resistance, isolation reliability is greatly increased, and the linearity of the whole isolator is guaranteed; the problem of the Hall element that null shit is not stable is resolved by the null shift compensating function of the isolation/null shift compensating circuit, and thereby the operation of the whole broadband linear voltage isolator is simpler, more stable, and more reliable; common mode interference is reduced by the difference input/power amplification circuit formed by a high-precision operational amplifier; the linearity and output power of the voltage signal is guaranteed by the high-precision power amplifier.
Description
Technical field
The utility model relates to Automation of Welding field tests, relates in particular to a kind of broadband linear voltage isolator.
Background technology
Most welding machines used are all inverter type welders in the market, output harmonic wave component is larger, the DC voltage of DC welder output is not pure direct current, but pulsating direct current, frequency can be from direct current to 80kHz, uses common D.C. voltmeter, and the frequency range that can measure only has below 1KHz, so have frequency loss, the accuracy that impact is measured.The waveform of some ac square wave welding machine output neither be sinusoidal wave, but square wave, harmonic content is also very high.Use the real effective table measurement of 45-65Hz also to have measuring error.Known linear voltage isolator at present, the modes such as Hall voltage sensor, isolation amplifier that mainly contain form.Bandwidth can reach more than 100KHz, that the linearity can reach price below 0.2% is very expensive.
Measure in using and often run into the instantaneous high pressure of 3000V at electric welding machine, can be easy to breakdownly if voltage table does not add isolation, especially, in intellegent sampling system, if do not add isolation, high voltage may injure the safety of whole system.
Utility model content
The purpose of this utility model is just to provide in order to address the above problem a kind of broadband linear voltage isolator.
In order to achieve the above object, the utility model has adopted following technical scheme:
A kind of broadband linear voltage isolator, comprise input voltage dividing potential drop/holding circuit, difference input/power amplification circuit and isolation/zero compensating circuit that wafts, the input end of described input voltage dividing potential drop/holding circuit is the voltage input end of described broadband linear voltage isolator, the output terminal of described input voltage dividing potential drop/holding circuit is connected with the input end of input/power amplification circuit of described difference, the waft input end of compensating circuit of the output terminal of described difference input/power amplification circuit and described isolation/zero is connected, the waft output terminal of compensating circuit of described isolation/zero is the voltage output end of described broadband linear voltage isolator.
Particularly, described input voltage dividing potential drop/holding circuit comprises the first resistance, the second resistance, the 3rd resistance, thermistor and voltage dependent resistor (VDR), the first voltage input end of described broadband linear voltage isolator is connected with the first end of described thermistor, the second end of described thermistor is connected with the first end of described the first resistance and the first end of described voltage dependent resistor (VDR) respectively, the second end of described voltage dependent resistor (VDR) connects the first end of described the 3rd resistance, the second voltage input end of described broadband linear voltage isolator and the first output terminal of described input voltage dividing potential drop/holding circuit, the second end of described the 3rd resistance is connected with the first end of described the second resistance and the second output terminal of described input voltage dividing potential drop/holding circuit respectively, the second end of described the second resistance is connected with the second end of described the first resistance and the 3rd output terminal of described input voltage dividing potential drop/holding circuit respectively.
Particularly, described difference input/power amplification circuit comprises high precision operating amplifier, high-precision power amplifier, the 4th resistance, the 5th resistance, the 6th resistance, the 7th resistance, the 8th resistance and the 9th resistance, the first power supply is respectively described high precision operating amplifier and the power supply of described high-precision power amplifier, the 3rd output terminal of described input voltage dividing potential drop/holding circuit is connected with the first end of described the 4th resistance, the second output terminal of described input voltage dividing potential drop/holding circuit is connected with the first end of described the 5th resistance, the first output terminal of described input voltage dividing potential drop/holding circuit connects the first common port after being connected with the first output terminal of the first end of described the 9th resistance and described difference input/power amplification circuit again, the second end of described the 4th resistance is connected with described the 6th first end of resistance and the first input end of described high precision operating amplifier respectively, the second end of described the 5th resistance is connected with the second input end of described high precision operating amplifier, the second end of described the 6th resistance is connected with described the 7th first end of resistance and the output terminal of described high precision operating amplifier respectively, the second end of described the 7th resistance is connected with the first end of described the 8th resistance and the first input end of described high-precision power amplifier respectively, the second end of described the 9th resistance is connected with the second input end of described high-precision power amplifier, the second end of described the 8th resistance is connected with the second output terminal of the output terminal of described high-precision power amplifier and described difference input/power amplification circuit.
Difference input/the power amplification circuit of high precision operating amplifier composition has lowered common mode interference, and high-precision power amplifier has ensured the linearity and the output power of voltage signal.
Particularly, described isolation/zero compensating circuit that wafts comprises LA25-NP type Hall element, potentiometer, the tenth resistance, the 11 resistance and the 12 resistance, the common port of described LA25-NP type Hall element is connected with the first output terminal of input/power amplification circuit of described difference, the input end of described LA25-NP type Hall element is connected with the second output terminal of input/power amplification circuit of described difference, the signal output part of described LA25-NP type Hall element respectively with the sliding end of described potentiometer, the first end of described the tenth resistance, the first voltage output end of broadband linear voltage isolator connects, the second voltage output terminal of the second end of described the tenth resistance and described broadband linear voltage isolator is connected to the second common port, the first end of described potentiometer is connected with the first end of described the 11 resistance, the second end of described the 11 resistance and the positive source of Hall element connect the positive pole of second source, the second end of described potentiometer is connected with the second end of described the 12 resistance, the second end of described the 12 resistance and the power cathode of Hall element connect the negative pole of second source.
Adopt LA25-NP type Hall element that the linearity 0.2%, overall accuracy are 0.5% as block isolating device part, this Hall element isolation voltage can reach 2500VRSM, input voltage is after electric resistance partial pressure, in the time that input voltage is 3000V, voltage after dividing potential drop only has about 60 volts, greatly increase isolation reliability, also ensured the linearity of whole isolator; Isolation/zero zero of the compensating circuit compensate function that wafts that wafts has made up the Hall element zero unstable problem of wafing, and makes whole broadband linear voltage isolator operation simpler, and reliable and stable.
The beneficial effects of the utility model are:
The utility model broadband linear voltage isolator, adopt LA25-NP type Hall element as block isolating device part, input voltage is after electric resistance partial pressure, in the time that input voltage is 3000V, voltage after dividing potential drop only has about 60 volts, greatly increase isolation reliability, also ensured the linearity of whole isolator; Isolation/zero zero of the compensating circuit compensate function that wafts that wafts has made up the Hall element zero unstable problem of wafing, and makes whole broadband linear voltage isolator operation simpler, and reliable and stable; Difference input/the power amplification circuit of high precision operating amplifier composition has lowered common mode interference, and high-precision power amplifier has ensured the linearity and the output power of voltage signal.
Brief description of the drawings
Fig. 1 is the circuit diagram of the utility model broadband linear voltage isolator.
Embodiment
Below in conjunction with accompanying drawing, the utility model is described in further detail:
As shown in Figure 1, a kind of broadband linear voltage of the utility model isolator, comprise input voltage dividing potential drop/holding circuit, difference input/power amplification circuit and isolation/zero compensating circuit that wafts, the input end of input voltage dividing potential drop/holding circuit is the voltage input end of broadband linear voltage isolator, the output terminal of input voltage dividing potential drop/holding circuit is connected with the input end of difference input/power amplification circuit, the waft input end of compensating circuit of the output terminal of difference input/power amplification circuit and isolation/zero is connected, isolation/zero output terminal that wafts compensating circuit is the voltage output end of broadband linear voltage isolator.
Input voltage dividing potential drop/holding circuit comprises the first resistance R 1, the second resistance R 2, the 3rd resistance R 3, voltage dependent resistor (VDR) RV and thermistor Rt, the first voltage input end of broadband linear voltage isolator is connected with the first end of thermistor Rt, the second end of thermistor Rt is connected with the first end of the first resistance R 1 and the first end of voltage dependent resistor (VDR) RV respectively, the second end of voltage dependent resistor (VDR) RV connects the first end of the 3rd resistance R 3, the second voltage input end of broadband linear voltage isolator and the first output terminal of input voltage dividing potential drop/holding circuit, the second end of the 3rd resistance R 3 is connected with the first end of the second resistance R 2 and the second output terminal of input voltage dividing potential drop/holding circuit respectively, the second end of the second resistance R 2 is connected with the second end of the first resistance R 1 and the 3rd output terminal of input voltage dividing potential drop/holding circuit respectively.
Difference input/power amplification circuit comprises high precision operating amplifier IC1, high-precision power amplifier IC2, the 4th resistance R 4, the 5th resistance R 5, the 6th resistance R 6, the 7th resistance R 7, the 8th resistance R 8 and the 9th resistance R 9, the first power supply is respectively high precision operating amplifier IC1 and high-precision power amplifier IC2 power supply, the 3rd output terminal of input voltage dividing potential drop/holding circuit is connected with the first end of the 4th resistance R 4, the second output terminal of input voltage dividing potential drop/holding circuit is connected with the first end of the 5th resistance R 5, the first output terminal of input voltage dividing potential drop/holding circuit connects the first common port after being connected with the first output terminal of the first end of the 9th resistance R 9 and difference input/power amplification circuit again, the second end of the 4th resistance R 4 is connected with the first end of the 6th resistance R 6 and the first input end of high precision operating amplifier IC1 respectively, the second end of the 5th resistance R 5 is connected with the second input end of high precision operating amplifier IC1, the second end of the 6th resistance R 6 is connected with the first end of the 7th resistance R 7 and the output terminal of high precision operating amplifier IC1 respectively, the second end of the 7th resistance R 7 is connected with the first end of the 8th resistance R 8 and the first input end of high-precision power amplifier IC2 respectively, the second end of the 9th resistance R 9 is connected with the second input end of high-precision power amplifier IC2, the second end of the 8th resistance R 8 is connected with the output terminal of high-precision power amplifier IC2 and the second output terminal of difference input/power amplification circuit.
Isolation/zero compensating circuit that wafts comprises LA25-NP type Hall element IC3, potentiometer RP, the tenth resistance R 10, the 11 resistance R the 11 and the 12 resistance R 12, the common port of LA25-NP type Hall element is connected with the first output terminal of difference input/power amplification circuit, the input end of LA25-NP type Hall element is connected with the second output terminal of difference input/power amplification circuit, the signal output part of LA25-NP type Hall element respectively with the sliding end of potentiometer RP1, the first end of the tenth resistance R 10, the first voltage output end of broadband linear voltage isolator connects, the second voltage output terminal of the second end of the tenth resistance R 10 and broadband linear voltage isolator is connected to the second common port COM2, the first end of potentiometer RP1 is connected with the first end of the 11 resistance R 11, the second end of the 11 resistance R 11 and the positive source of Hall element meet the anodal VCC2+ of second source, the second end of potentiometer RP1 is connected with the second end of the 12 resistance R 12, the second end of the 12 resistance R 12 and the power cathode of Hall element meet the negative pole VCC2-of second source.
Principle of work of the present utility model:
Tested voltage, after bleeder circuit step-down, changes into linear current signal by difference channel, power amplifier and noninductive precision resistance by the voltage signal after dividing potential drop, then by Hall element, linear current model is changed into the voltage signal output of isolation.The zero compensating circuit zero point drift when the zero input voltage model by compensation Hall element of wafing, the linearity while ensureing tested low value input voltage signal conversion.
The foregoing is only preferred embodiment of the present utility model, be not limited to the utility model, for a person skilled in the art, the utility model can have various modifications and variations.All within spirit of the present utility model and principle, any amendment of doing, be equal to replacement, improvement etc., within being all included in protection scope of the present invention.
Claims (4)
1. a broadband linear voltage isolator, it is characterized in that: comprise input voltage dividing potential drop/holding circuit, difference input/power amplification circuit and isolation/zero compensating circuit that wafts, the input end of described input voltage dividing potential drop/holding circuit is the voltage input end of described broadband linear voltage isolator, the output terminal of described input voltage dividing potential drop/holding circuit is connected with the input end of input/power amplification circuit of described difference, the waft input end of compensating circuit of the output terminal of described difference input/power amplification circuit and described isolation/zero is connected, the waft output terminal of compensating circuit of described isolation/zero is the voltage output end of described broadband linear voltage isolator.
2. broadband linear voltage isolator according to claim 1, it is characterized in that: described input voltage dividing potential drop/holding circuit comprises the first resistance, the second resistance, the 3rd resistance, thermistor and voltage dependent resistor (VDR), the first voltage input end of described broadband linear voltage isolator is connected with the first end of described thermistor, the second end of described thermistor is connected with the first end of described the first resistance and the first end of described voltage dependent resistor (VDR) respectively, the second end of described voltage dependent resistor (VDR) connects the first end of described the 3rd resistance, the second voltage input end of described broadband linear voltage isolator and the first output terminal of described input voltage dividing potential drop/holding circuit, the second end of described the 3rd resistance is connected with the first end of described the second resistance and the second output terminal of described input voltage dividing potential drop/holding circuit respectively, the second end of described the second resistance is connected with the second end of described the first resistance and the 3rd output terminal of described input voltage dividing potential drop/holding circuit respectively.
3. broadband linear voltage isolator according to claim 1 and 2, it is characterized in that: described difference input/power amplification circuit comprises high precision operating amplifier, high-precision power amplifier, the 4th resistance, the 5th resistance, the 6th resistance, the 7th resistance, the 8th resistance and the 9th resistance, the first power supply is respectively described high precision operating amplifier and the power supply of described high-precision power amplifier, the 3rd output terminal of described input voltage dividing potential drop/holding circuit is connected with the first end of described the 4th resistance, the second output terminal of described input voltage dividing potential drop/holding circuit is connected with the first end of described the 5th resistance, the first output terminal of described input voltage dividing potential drop/holding circuit connects the first common port after being connected with the first output terminal of the first end of described the 9th resistance and described difference input/power amplification circuit again, the second end of described the 4th resistance is connected with described the 6th first end of resistance and the first input end of described high precision operating amplifier respectively, the second end of described the 5th resistance is connected with the second input end of described high precision operating amplifier, the second end of described the 6th resistance is connected with described the 7th first end of resistance and the output terminal of described high precision operating amplifier respectively, the second end of described the 7th resistance is connected with the first end of described the 8th resistance and the first input end of described high-precision power amplifier respectively, the second end of described the 9th resistance is connected with the second input end of described high-precision power amplifier, the second end of described the 8th resistance is connected with the second output terminal of the output terminal of described high-precision power amplifier and described difference input/power amplification circuit.
4. broadband linear voltage isolator according to claim 3, it is characterized in that: described isolation/zero compensating circuit that wafts comprises LA25-NP type Hall element, potentiometer, the tenth resistance, the 11 resistance and the 12 resistance, the common port of described LA25-NP type Hall element is connected with the first output terminal of input/power amplification circuit of described difference, the input end of described LA25-NP type Hall element is connected with the second output terminal of input/power amplification circuit of described difference, the signal output part of described LA25-NP type Hall element respectively with the sliding end of described potentiometer, the first end of described the tenth resistance, the first voltage output end of broadband linear voltage isolator connects, the second voltage output terminal of the second end of described the tenth resistance and described broadband linear voltage isolator is connected to the second common port, the first end of described potentiometer is connected with the first end of described the 11 resistance, the second end of described the 11 resistance and the positive source of Hall element connect the positive pole of second source, the second end of described potentiometer is connected with the second end of described the 12 resistance, the second end of described the 12 resistance and the power cathode of Hall element connect the negative pole of second source.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201420120479.8U CN203745514U (en) | 2014-03-18 | 2014-03-18 | Broadband linear voltage isolator |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201420120479.8U CN203745514U (en) | 2014-03-18 | 2014-03-18 | Broadband linear voltage isolator |
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| Publication Number | Publication Date |
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| CN203745514U true CN203745514U (en) | 2014-07-30 |
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| CN201420120479.8U Expired - Fee Related CN203745514U (en) | 2014-03-18 | 2014-03-18 | Broadband linear voltage isolator |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109900947A (en) * | 2019-04-11 | 2019-06-18 | 湘潭大学 | A kind of isolation voltage sample circuit for PWM rectifier |
-
2014
- 2014-03-18 CN CN201420120479.8U patent/CN203745514U/en not_active Expired - Fee Related
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109900947A (en) * | 2019-04-11 | 2019-06-18 | 湘潭大学 | A kind of isolation voltage sample circuit for PWM rectifier |
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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: 20140730 Termination date: 20150318 |
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| EXPY | Termination of patent right or utility model |