CN2132193Y

CN2132193Y - Electronic type parity checker for mutual-inductor

Info

Publication number: CN2132193Y
Application number: CN 92229682
Authority: CN
Inventors: 杨传旺
Original assignee: Individual
Current assignee: Individual
Priority date: 1992-08-05
Filing date: 1992-08-05
Publication date: 1993-05-05
Anticipated expiration: 2002-08-05

Abstract

The utility model relates to an electronic parity checker for a mutual-inductor, which is characterized in that after the standard sampling, an operational amplifier and an integral additional conductance case for phase shifting form a sampling-regulating circuit for standard signals so as to carry out comparative measurement on a measured difference value signal; electronic elements form a dial gauge circuit. The utility model has advantages that the electronic parity checker with directly readable errors measured in min and a measuring error range from 10<-1 > to 10<-7 > is suitable for the mutual-inductor transfer of a current comparator and the mutual-inductors above 0.05 stage checked by the comparator. The linear dial gauge has the precision of 1.5 level. The utility model is especially suitable for measuring the error and the impedance of voltage mutual-inductors with secondary currents of 5A, 2A, 1A, 0.5A or voltage mutual-inductors with secondary voltages of 100V and 100/3V and magnifications of 0.1, 1.1, 1.2, 1.5, 2, 2.2.

Description

Electronic type parity checker for mutual-inductor

The utility model is a kind of electronic type mutual inductance tester, is specially adapted to transducer check, and to the measurement of current comparator, inductive voltage divider and impedance.

The measurement of transformer error, tradition are to utilize standard mutual inductor and tested mutual inductor comparing measurement with under the no-load voltage ratio by tester.The ratio error f of electric current and voltage transformer (VT) with % represent, relative error δ is with dividing or radian % represents.

At present, China's mutual-inductor tester is selected HEG in a large number for use ₂Type and HEG ₄Type and derivatives thereof.As HEG ₂The circuit structure of type mutual-inductor tester is a basic engineering to measure current transformer, its structure is: the sampling of 0.1 Ω measuring resistance, normalized current changes into magnitude of voltage, be divided into two groups of voltage signals through the multiplying power transformer, convert in-phase current with phasor to through the adjustable electric guide box, amount of quadrature converts quadrature current to by the adjustable electric tank.This two electric current and measured error current are input to current comparator jointly, carry out equilibrium ratio, with the relative error that obtains to measure.Be f and δ.

When surveying voltage transformer (VT), utilize normal voltage by the little voltage input multiplying power transformer of the ratio that converts to of voltage transformer (VT), utilize the method for current measurement circuit to change into the homophase and the quadrature current signal of standard again, again tested error voltage is changed into current signal by measuring resistance, utilize current comparator to measure relative error.Be f and δ value.

The shortcoming of above-mentioned prior art is:

(1) measuring standard current value, equivalent analysis are that the measuring resistance shunting obtains.Bigger at fundamental quantity limit quadrature reading partial current when being divided into unit, be difficult to satisfy the direct-reading requirement, so multiply by 0.5 or 0.1 multiplying power, cause can not direct-reading trouble.

(2) capacitive and the internal resistance of multiplying power transformer lead series connection causes phase shift, so to forming error with phasor.

(3) the multiplying power Transformer Winding is many, and the number of turn is many, and lead is thick, manual technique for coiling complexity, and the production cycle is long.

(4) dial gauge of dress also obtains about the about 1V of signal from the multiplying power transformer in the tester, adopts rectifier structure, makes measurement point 5%, 10%, 20% enter the diode nonlinear area, is difficult to accurately read, and causes measuring error.Be difficult to satisfy standard-required.

(5) owing to adopt electric guide box and capacitive, its structure is existing four-layer switch, and volume is big, and weight is big, and the life-span is difficult to satisfy 100,000 requirements of standard code.

The purpose of this utility model is to overcome the shortcoming of prior art, provides a kind of transformer simple in structure to substitute the multiplying power transformer; Utilize the indirect output signal of operational amplifier to replace directly extracting signal; Utilize 90 ° of transposition of operational amplifier circuit, amplifying circuit and multidigit electricity guide box to replace multidigit capacitive, outputting standard orthogonal signal.Utilize operational amplifier to form linear dial gauge again and replace the non-linear dial gauge of former rectification, the mutual-inductor tester that just can obtain to satisfy international standard, be easy to process, cost is low, precision is high.

The purpose of this utility model solves by following scheme:

1, the measurement standard signal section of current transformer is: normalized current is by measuring resistance R ₀Obtain voltage after the sampling, through 1:1 isolating transformer T ₁Obtain signal, pass through K switch _1aBe connected to enlargement factor and be 1 two-stage paraphase operational amplifier, can obtain the standard signal of positive and negative two opposite phases, this signal divides two-way output by two switches: the one tunnel is to correspond to the f value through four decimal system adjustable electric guide box conversions at the adjustable normalized current of in-phase signal; Another road through 90 ° of transposition integrating circuit and proportional amplifiers, voltage follower, four decimal system adjustable electric guide boxes after the adjustable normalized current of output orthogonal phase place correspond to the δ value.To be input to comparator after the above-mentioned two-way electric current stack, compare, and carry out difference and measure with tested difference current signal.

2, voltage measuring transformer standard signal part: standard potential transformer T ₂Secondary Winding one end ground connection, the other end is connected on by resistance in series R ₁, R ₂On the resitstance voltage divider of forming, by switch this signal to be input to enlargement factor be 1 two-stage paraphase operational amplifier for the signal obtained after this sampling, again through using a circuit together with current transformer measurement standard signal section, but differential pressure signal changes into electric current by resistance and is input to comparator, compare with standard signal, carry out difference and measure.

3, dial gauge indicating section: include two performances of electric current dial gauge and voltage dial gauge.

A. the electric current dial gauge partly is: electric current is through 0.1 Ω measuring resistance R ₀Sampling is after 1:1 isolating transformer T ₁, be input to operational amplifier and resitstance voltage divider, pass through the linear AC-DC converter of amplifier again, indicate by 100 μ A gauge outfits.

B. the voltage dial gauge partly is: voltage transformer (VT) T ₂After the sampling, the signal of obtaining is input to resitstance voltage divider and obtains the different multiplying signal, through switch above-mentioned signal is selected, and will choose signal and be input to operational amplifier and the linear AC-DC converter of amplifier, by being connected in parallel on dial gauge indication on the converter.

4, polarity indicating section:

A. voltage segment: by with the joining resistance R of sampled point K ₂₀Be serially connected in diode D ₁₁, 15V stabilivolt D ₈With light emitting diode D ₉Back ground connection is formed.When voltage surpasses 12V, D ₉Conducting is luminous; Voltage is no more than not conducting of 10V.

B. current segment: adopt a current transformer T ₃A winding be serially connected between difference stream input end D and the instrument ground T ₃Secondary Winding and connecting resistance R ₂₁Obtain voltage, R ₂₁An end ground connection, its other end connects diode D ₁₀After be connected on the light emitting diode D D when electric current selects 0.7～0.8A) for use greater than 0.6A( ₉Luminous, T during design ₃The primary side internal impedance is minimum, and is unaffected to measuring.

5, four decimal system adjustable electric guide boxes in the utility model are led the switch connection by four identical electricity of structure and are formed, each electricity is led switch and is included two sliding plates, and each sliding plate is all led with the light pressure switch 2D11K of wheel and formed by 0～10 bit switch, 5 electricity.

Advantage of the present utility model:

1, since measuring standard current value by operational amplifier input end sampling, the impedance height, hardly from the measuring resistance shunting, and operational amplifier directly provides electric current, satisfies each grade direct-reading requirement.

2, the quadrature normalized current is by the integrating circuit phase shift, and the follower output voltage produces the quadrature current signal by electric guide box, not only reduces cost, and eliminates the phase shift error that causes in former electric capacity and lead internal resistance series connection simultaneously.

3, owing to adopt four the adjustable individual event electricity of decimal system guide boxes, can reach and reduce cost, operate easy manufacturing brisk, simple in structure, long advantage of life-span, this structure is exported by operational amplifier as adopting, the electricity guide box is transferred the electric current structure, can reduce the interference of the own signal noise of operational amplifier to measuring when micro-signal.

4, because the change of circuit structure makes prior art moderate multiplying factor transformer be simplified to a simple double winding isolating transformer, can fall man-hour, fall cost.

5, interior dress dial gauge adopts electric resistance partial pressure, operational amplifier changing voltage and AC-DC amplifier converter,linear, and forming linear graduation 5%, 10%, 20% can clearly represent, thereby guarantees measuring accuracy.

6, the utility model guarantees operating accuracy with 1～3 times of amplification quantity, and this accuracy of instrument is 0.5～1 grade; Error measure scope: 10 ^-1～10 ^-7Dial gauge is linear, and precision is 1.5 grades, and the particularly suitable secondary current is that current transformer and the secondary voltage of 5A, 2A, 1A, 0.5A is 100V, 100/

V, 100/3V and multiplying power thereof are the error measure and the impedance measurement of 0.1,1,1.1,1.2,1.5,2,2.2 the mutual device of voltage.Range of current: 1～120%, voltage range: 2～190%.The utility model power supply can adopt ± the 6V powered battery, and maximum current is less than 30mA, and it is little to consume energy.Also can adopt external power supply.

Description of drawings:

Fig. 1 is the utility model schematic appearance;

Fig. 2 is the utility model circuit structure diagram;

Fig. 3 is the block scheme of circuit structure among Fig. 2;

Fig. 4 is four decimal system adjustable electric guide box circuit structure diagrams among Fig. 2.

In conjunction with the accompanying drawings embodiment of the present utility model is described in further detail:

Pick-up unit has dial gauge 10, galvanometer gauge outfit 6, galvanometer sensitivity levelling switch 22, standard current transformer current input terminal T on the panel of the utility model casing 1 ₀ Be 13, tested transformer current input terminal T _XBe 14, voltage standard input terminal x and a are respectively 12 and 11, and tested differential pressure or difference stream input terminal K and D are respectively 5 and 4, and ground terminal is 3, and the comparator signal plug is 2, amount limit selector switch K _1a, K _1b, be 16, amount limit is selected voltage multiplying power K switch ₂Be 15, measure selector switch K ₁₃Be 8, difference signal multiplying power K switch ₁₄Be 28, regulate the electricity of the electric guide box of f with phasor and lead K switch ₅, K ₆, K ₇, K ₈Be respectively 17,18,19,21, and f positive and negative K switch is housed ₃Be 20, amount of quadrature δ regulates the electricity of electric guide box and leads K switch ₉, K ₁₀, K ₁₁, K ₁₂Be respectively 23,25,26,27, the selector switch K of its δ unit ₁₃Be 7, the positive and negative K switch of its δ ₄Be 24, polarity indication D ₉Be 9, power switch 29 also is housed on the panel.

The circuit that links with pick-up unit on casing 1 panel is arranged on the circuit board in the casing 1, and its structure is:

(1) current transformer measurement standard signal section:

T ₁Be the 1:1 isolating transformer.The secondary current of standard mutual inductor is by T ₁T ₀The end input, the secondary current of tested mutual inductor is by T ₁T _XThe end input, T _XEnd ground connection.R ₀Be that 0.1 Ω measuring resistance is connected on T ₀And T _XBetween.Secondary voltage signal T ₀' end is through K switch _1aResistance R is passed through in selection ₃With operational amplifier IC ₁Negative input end links, resistance R ₄Be attempted by IC ₁Output terminal and negative input end between, T _X' end and IC ₁Positive input terminal join the back ground connection, IC ₁Output terminal connect K switch respectively ₃, K ₄Negative sign (-) end, be serially connected in resistance R simultaneously ₅With operational amplifier IC ₂Negative input end, resistance R ₆Be attempted by IC ₂Between output terminal and the negative input end, IC ₂Positive input terminal ground connection, IC ₂Output terminal meet K respectively ₃, K ₄The positive sign end, IC ₁And R ₂, R ₄IC ₂And R ₅, R ₆Be that two enlargement factors are 1 phase inverter.By K ₃The train of signal of choosing is connected on by K switch ₅, K ₆, K ₇, K ₈Four decimal system adjustable electric guide box G that form ₁After be input to comparator A end, be the standard figures f of plus or minus in-phase component.By K ₄The signal of choosing is through resistance in series R ₇Receive operational amplifier IC ₃Negative input end, capacitor C ₁Be attempted by IC ₃Output terminal and negative input end between, IC ₃Positive input terminal ground connection.By resistance R ₈, R ₉, capacitor C ₂Form T type circuit and be attempted by C ₁Two ends provide DC feedback loop to operational amplifier, form 90 ° of integrating circuit transposition like this.IC ₃Output terminal resistance in series R ₁₀With operational amplifier IC ₄Negative input end joins, resistance R ₁₁, R ₁₂Be serially connected in IC ₄Negative input end and output terminal, at R ₁₁, R ₁₂Single-pole switch K is arranged on the contact ₁₃, K ₁₃Can select the amplifying signal of 1:1 and 1:2.91, obtaining with " % " or " branch " is the signal of unit.IC ₄Output terminal series capacitance C ₃Receive operational amplifier IC ₅, IC ₆, IC ₇Positive input terminal, and pass through resistance R ₁₆Back ground connection.Resistance R ₁₃, R ₁₄, R ₁₅Be connected on IC respectively ₅, IC ₆, IC ₇Output terminal and negative input end between, IC ₅, IC ₆, IC ₇Output terminal also connects the voltage follower that the back is formed.This voltage follower is serially connected in by K switch ₉, K ₁₀, K ₁₁, K ₁₂Four decimal system adjustable electric guide box G that form ₂After be input to the A point of comparator, be the standard figures of plus or minus quadrature component.

The ratio difference f unit that the numerical value of in-phase component corresponds to transformer error is that % represents.

The phase differential δ unit that the numerical value of quadrature component corresponds to transformer error represents with " branch " or " % ".

(2) voltage measuring transformer standard signal part:

T ₂Voltage transformer (VT) for 100/1-2.Capacitor C ₀Be attempted by T ₂A winding on, the secondary voltage of standard mutual inductor is by T ₂A and x end input, T ₂Secondary Winding one end ground connection, another termination is by resistance in series R ₁, R ₂The voltage divider of forming.Through T ₂Transformation and R ₁, R ₂Dividing potential drop can obtain 1000/1 voltage signal, passes through K _1aOutput is through R ₃With IC ₁Connect, again through using a circuit together with current transformer measurement standard signal section.Relatively carrying out difference with standard signal after the input of differential pressure signal measures.

(3) to adopt original technology be to be wound with zero-detection winding W on the iron stamen of Zai Po Mo alloy to current comparator ₁, the extremely near D of protection two ₁, D ₂Be attempted by W ₀On.At W ₀Outer is double-deck electrostatic sheild, is around with W at electrostatic sheild _AWinding.W _AThree end points of 100:10:1 are arranged, respectively with the multiplying power K switch ₁₄Link, when the error of measurement current signal obtains taking advantage of 1, takes advantage of 10, takes advantage of 100 3 multiplying powers; When error of measurement voltage, K ₁₄Can connect three different resistance resistance R respectively ₁₇, R ₁₈, R ₁₉After receive the A point, obtain taking advantage of 1, take advantage of 10, take advantage of 100 3 multiplying powers.

(4) polarity indicating section: measuring error voltage, current signal are imported by K, D point

A. voltage segment: the resistance R of joining with sampled point K ₂₀Be serially connected in diode D ₁₁, voltage stabilizing diode D ₈With light emitting diode D ₉Back ground connection.

B. current segment: current transformer T ₃A winding one termination instrument ground, another termination D point, T ₃Secondary Winding and connecting resistance R ₂₁Obtain voltage, R ₂₁One end ground connection, its other end connects diode D ₁₀After be connected on light emitting diode D ₉On.

When error signal is imported through K switch by K, D point ₁₄Select, be input to comparator simultaneously with adjustable standard signal, at W ₀End passes through K switch ₁₅, K ₁₆Connect the power frequency galvanometer, the adjustment criteria signal makes the galvanometer position of making zero, and measures.Two electric guide box G ₁, G ₂Reading multiply by multiplying power and is measured error numerical value.

(5) including two performances of electric current dial gauge and voltage dial gauge in the dial gauge circuit, is to be 100% nominal with ratings, and maximal value is 120%.Circuit structure is as follows:

(1) the electric current dial gauge is: 0.1 Ω measuring resistance R ₀After the sampling, through T ₁Isolating transformer, T ₁Secondary winding T _X' end ground connection, T ₀' terminate to operational amplifier IC ₈Positive input terminal, IC ₈Output terminal and negative input end between and connecting resistance R ₁₁₆, IC ₈Negative input end connecting resistance R ₁₁₅Back ground connection.IC ₈, R ₁₁₅, R ₁₁₆Form 2 times proportional amplifier, IC ₈The output termination is by resistance in series R ₁₁₈, R ₁₁₉, R ₁₂₀The resitstance voltage divider of forming is connected on K respectively ₁₆Four contacts on, through K ₁₆It is 0.5A, 1A, 2A, 5A that selection can obtain current value, and the amount of exports definite value is the voltage signal of 0.1V.K ₁₆Other end series capacitance C ₁₀₁Amplify IC with computing ₁₀Positive input terminal, IC ₁₀Output terminal serial connection protective resistance R ₁₂₄After connect by diode D ₃, D ₄, D ₅, D ₆Bridge circuit one end of forming, another termination of bridge circuit IC ₁₀Negative input end, and pass through capacitor C ₁₀₂With resistance R ₁₂₂And resistance R ₁₂₃The series connection contact joins R ₁23 other end ground connection, R ₁₂₂The other end is connected on IC ₁₀Positive input terminal, in the middle of the bridge circuit that diode is formed, insert 100 μ A reometers 10 and protection diode D ₇IC ₁₀, D ₃, D ₄, D ₅, D ₆Reometer and C ₁₀₂, C ₁₀₃Form linear AC-DC converter.Guarantee linear indication output, represent indication by dial gauge.

(2) voltage dial gauge: the standard potential transformer secondary voltage is through voltage transformer (VT) T ₂The a of a winding, the input of x two ends, capacitor C ₀Be attempted by between a, x two ends T ₂Secondary Winding one end a ' ground connection, other end x ' connects by resistance in series R ₁₀₁, R ₁₀₂, R ₁₀₃, R ₁₀₄, R ₁₀5, R ₁₀₆, R ₁₀₇, R ₁₀₈Ground connection behind the composition resitstance voltage divider.K switch ₂Connect each corresponding point on the above-mentioned voltage divider,, pass through K to obtain taking advantage of 0.1, take advantage of 1, take advantage of 1.1, take advantage of 1.2, take advantage of 1.5, take advantage of 2, to take advantage of 2.2 voltage dial gauge multiplying power ₂Selection meets operational amplifier IC ₉Positive input terminal, resistance R ₁₁₁Be attempted by IC ₉Output terminal and negative input end between, and connection electrical resistance R ₁₁₀Back ground connection is by R ₁₁₁, R ₁₁₀, IC ₉Form one 3 times proportional amplifier, IC ₉The output termination is with by resistance in series R ₁₁₂, R ₁₁₃, R ₁₁₄On the voltage divider of forming, insert K switch respectively ₁₆Corresponding point, obtaining to be respectively load voltage value is 100V, 100/

V, 100/3V, and the amount of exports definite value is the voltage signal of 0.1V, passes through K ₁₆Selection, connect C ₁₀₁Be input to IC ₁₀Positive input terminal, again by by IC ₁₀And the diode that joins, reometer is formed linear AC-DC converter, with the same circuit of electric current dial gauge, and its numerical value electricity dial gauge indication.If K ₁₆Omit IC after the output ₁₀Deng AC-DC linear transform circuit of forming and dial gauge indication, change 3 1/2 bit digital of the interchange 200mV retaining of commercial usefulness and represent that gauge outfit then is digital dial gauge.

(6) electric guide box G of the present utility model ₁And G ₂Adopt four decimal system adjustable structures, this electricity guide box is to lead K switch by four identical electricity of structure ₅, K ₆, K ₇, K ₈Or K ₉, K ₁₀, K ₁₁, K ₁₂Connect and form.Each electricity is led switch and is comprised two sliding plates, each sliding plate all has 0～10 bit switch, 5 electricity are led the light pressure switch 2D11K of 1g, 1g, 3g, 4g, 6g and wheel, and electricity is led 1g one and terminated on the G point, and its other end is connected on 5 bit switches of

ground floor

1,7 bit switches and the second layer; Electricity is led 2g one and is terminated on the G point, and the other end is connected on 2,8 bit switches of ground floor; Electricity is led 3g one and is terminated on the G point, and the other end is connected on 3,9 bit switches of ground floor; Electricity is led 4g one and is terminated on the G point, the other end is connected on 4,10 bit switches of ground floor, electricity is led 6g one and is terminated on the G point, and the other end is connected on 6,7,8,9,10 bit switches of the second layer, and the ratio 1g:2g:3g:4g:6g that electricity is led is 1:2:3:4:6 a times of g.Two-layer sliding plate all is connected on G '.Switch 2D11K useful commercial 2D12K replaces, and a room can be arranged, and uses this light pressure switch can satisfy standard 10

Claims

1, a kind of electronic transducer calibration instrument, the pick-up unit that mainly is included on this tester cabinet panel has dial gauge, galvanometer, connection terminal, adjusting turn-knob switch, polarity index, power switch, at the box house circuit sampling resistor, operational amplifier, comparator, and resistance, electric capacity are arranged on extremely, it is characterized in that with cabinet panel on the joining circuit structure of pick-up unit be:

(1) the measurement standard signal section of current transformer is: normalized current is by measuring resistance R ₀Obtain voltage after the sampling, through 1: 1 isolating transformer T ₁Obtain signal, pass through K switch _1aBe connected to enlargement factor and be 1 two-stage paraphase operational amplifier, can obtain the standard signal of positive and negative two opposite phases, this signal divides two-way output by two switches: the one tunnel is to convert the adjustable normalized current of in-phase signal to through four decimal system adjustable electric guide boxes; Another road is through the adjustable normalized current of output orthogonal phase place behind 90 ° of transposition integrating circuit and proportional amplifiers, voltage follower, four decimal system adjustable electric guide boxes, be input to comparator after the above-mentioned two-way electric current stack, compare with tested difference current signal, carry out difference and measure;

(2) the measurement standard signal section of voltage transformer (VT); Voltage transformer (VT) T ₂Secondary Winding one end ground connection, its other end is connected on by resistance in series R ₁, R ₂On the voltage divider of forming, through switch this signal to be input to enlargement factor be 1 two-stage paraphase operational amplifier for the signal obtained after this sampling, again through using a circuit together with current transformer measurement standard signal section, but differential pressure signal converts electric current to by resistance, compare with standard signal, carry out difference and measure;

(3) dial gauge indicating section: include two performances of electric current dial gauge and voltage dial gauge, wherein;

A, electric current dial gauge partly are: electric current is through 0.1 Ω measuring resistance R ₀Sampling was through 1: 1 isolating transformer T ₁, being input to operational amplifier and resitstance voltage divider, the linear AC-DC converter of forming through the arithmetical unit amplifier is indicated by 100 μ A gauge outfits again;

B, voltage dial gauge partly are: voltage transformer (VT) T ₂The obtained signal in sampling back is input on the resitstance voltage divider, obtain the signal of different multiples, above-mentioned signal is selected through switch, the signal of choosing is input to the linear AC-DC converter that operational amplifier and operational amplifier are formed, indicate by 100 μ A gauge outfits;

(4) polarity indicating section:

A. voltage segment: this part is the resistance R of joining with sampled point K ₂₀Be serially connected in diode D ₁₁, stabilivolt D ₈With light emitting diode D ₉Back ground connection is formed;

B. current segment: current transformer T ₃A winding one end ground connection, the D point of another termination difference signal input end, T ₃Secondary Winding and connecting resistance R ₂₁Obtain voltage, R ₂₁One end ground connection, its other end series diode D ₁₀After be connected on light emitting diode D ₉On.

2, according to the tester described in the claim 1, it is characterized in that four decimal system adjustable electric guide boxes lead switch by four identical electricity of structure and connect and to form, each electricity is led switch and is comprised two sliding plates, each sliding plate all has 0～10 bit switch, 5 electricity to lead 1g, 2g, 3g, 4g, 6g and the wheel 2011K that gently compresses switch, the connecting mode that electricity is led is: the end that these 5 electricity are led all is connected on the G point, and the other end is respectively: 1g is connected on 5 bit switches of 1,7 bit switches of ground floor and the second layer; 2g is connected on 3,9 bit switches of ground floor; 4g is connected on 4,10 bit switches of ground floor; 6g is connected on 6,7,8,9,10 bit switches of the second layer, and the ratio 1g:2g:3g:4g:6g that electricity is led is 1:2:3:4:6 a times of g, and two layers of sliding plate are connected on G '.

3,, it is characterized in that two-stage paraphase operational amplifier is by resistance R according to claim 1 or 2 described testers ₃, R ₄With operational amplifier IC ₁The enlargement factor of forming is 1 phase inverter, connects one again by resistance R ₅, R ₆With operational amplifier IC ₂Another phase inverter of forming is formed, wherein R ₃Be connected on IC ₁Negative input end, IC ₁Positive input terminal ground connection, R ₄Be attempted by IC ₁Output terminal and negative input end between; R ₅Be connected on IC ₂Negative input end, IC ₂Positive input terminal ground connection, R ₆Be attempted by IC ₂Between output terminal and the negative input end.

4,, it is characterized in that 90 ° of transposition integrating circuit are by resistance R according to claim 1 or 2 described testers ₇Be serially connected in operational amplifier IC ₃Negative input end, capacitor C ₁Be attempted by IC ₃Output terminal and negative input end between, IC ₃Positive input terminal ground connection, resistance R ₈, R ₉, capacitor C ₂Form T type circuit and be attempted by C ₁Two ends are formed; Proportional amplifier is by resistance R ₁₀Be connected on operational amplifier IC ₄Negative input end, resistance R ₁₁, R ₁₂, be attempted by IC after the series connection ₄Between negative input end and the output terminal, R ₁₁, R ₁₂Contact be connected to single-pole switch K ₁₃, K ₁₃Can select the amplifying signal of 1:1 and 1:2.91, obtaining with " % " or " branch " is the signal of unit.

5,, it is characterized in that voltage follower is the operational amplifier IC by three parallel connections according to claim 1 or 2 described testers ₅, IC ₆, IC ₇Form, wherein, capacitor C ₃Be connected on IC ₅, IC ₆, IC ₇Positive input terminal, and pass through resistance R ₁₆Back ground connection, resistance R ₁₃, R ₁₄, R ₁₅Be attempted by IC respectively ₅, IC ₆, IC ₇Output terminal and negative input end between, IC ₅, IC ₆, IC ₇Output terminal also connects.

6,, it is characterized in that the dial gauge indicating section is according to claim 1 or 2 described testers:

(1) in the electric current dial gauge: operational amplifier and electric resistance partial pressure are by isolating transformer T ₁Secondary Winding one end ground connection, other end input operational amplifier IC ₈Positive input terminal, IC ₈Output terminal and negative input end between and connecting resistance R ₁₁₆, IC ₈Negative input end meets R ₁₁₅Back ground connection, IC ₈, R ₁₁₆, R ₁₁₅Form 2 times proportional amplifier, IC ₈The output termination is by resistance in series R ₁₁₈, R ₁₁₉, R ₁₂₀, R ₁₂₁The resitstance voltage divider of forming is connected on K respectively ₁₆Four contacts on, through K ₁₆It is 0.5A, 1A, 2A, 5A that selection can obtain load current value, and the amount of exports definite value is the voltage signal of 0.1V, K _1bOther end series capacitance C ₁₀₁With operational amplifier IC ₁₀Positive input terminal, IC ₁₀Output terminal serial connection protective resistance R ₁₂₄After connect by diode D ₃, D ₄, D ₅, D ₆One end of the bridge circuit of forming, another termination of bridge circuit IC ₁₀Negative input end, and pass through capacitor C ₁₀₂With resistance R ₁₂₂And R ₁₂₃The series connection contact joins R ₁₂₃Other end ground connection, R ₁₂₂The other end is connected on IC ₁₀Positive input terminal, insert 100 μ A gauge outfits and protection diode D in the middle of the bridge circuit ₇, IC ₁₀, D ₃, D ₄, D ₅, D ₆, 100 μ A gauge outfit and C ₁₀₂, C ₁₀₃, R ₁₂₃Form linear AC-DC converter;

(2) the voltage dial gauge is: voltage transformer (VT) T ₂Shunt capacitance C between two end points a, the x of a winding ₀, Secondary Winding one end ground connection, another termination is by resistance in series R ₁₀₁, R ₁₀₂, R ₁₀₃, R ₁₀₄, R ₁₀₅, R ₁₀₆, R ₁₀₇, R ₁₀₈, form ground connection behind the resitstance voltage divider, K switch ₂Connect on the voltage divider each corresponding point and pass through K to obtain taking advantage of 0,1, take advantage of 1, take advantage of 1.1, take advantage of 1.2, take advantage of 1.5, take advantage of 2, to take advantage of 2.2 voltage dial gauge multiplying power ₂Selection connects and is input to operational amplifier IC ₉Positive input terminal, resistance R ₁₁₁Be attempted by IC ₉Output terminal and negative input end between, and connection electrical resistance R ₁₁₀Back ground connection is by R ₁₁₁, R ₁₁₀, IC ₉Form three times proportional amplifier, IC ₉The output termination is with by resistance in series R ₁₁₂, R ₁₁₃, R ₁₁₄The voltage divider of forming inserts K switch respectively ₁6 corresponding point, obtaining to be respectively load voltage value is 100V, 100/

V, 100/3V, and the output definite value is the voltage signal of 0.1V, passes through K ₁₆Selection, connect C ₁₀₁Be input to IC ₁₀Positive input terminal passes through by IC again ₁₀And the resistance that joins, diode, reometer, form linear AC-DC converter, with the same circuit of electric current dial gauge, indicate by dial gauge.