CN2138795Y - Inductance inner resistance fast measurer - Google Patents

Abstract

The utility model discloses an intelligent fast measurer for inductance internal resistance, which is composed of a displayer 1, a microprocessor 2, a variable constant-current source 3, a measuring range distinguish, protecting and discharging circuit 4, a pre-amplifier 5 and an A/D converter 6. The utility model is mainly used for the measurement of direct current internal resistances of large-sized inductors, and has the advantages of short test time, easy operation, precise measurement, safety, without the need of manual discharge at the end of test, etc.

Description

Inductance inner resistance fast measurer

The utility model inductance internal resistance instrument for quick measuring is a kind of instrument that is mainly used in testing large inductor DC internal resistance.

Large-scale inductor, as power transformer, heavy-duty motor, its inductance DC internal resistance is very little, generally between hundreds of micro-ohms to one hundred Europe, inductance value is very big, reaches hundreds of to thousands of hertz, at present, the measurement of inductance internal resistance, usefulness be the bridge method tester, this quasi-instrument gives the test inductance by after the current i, after current i such as having only to reach stationary value I, the influence of inductance disappears, and by I=V/R, draws internal resistance R value.Depend on that (τ=L/R), need in theory just can arrive stable state through time t=∞ during time t=10 τ, can ignore inductive impact in the practical application to the intrinsic timeconstant of inductor itself transit time that reaches stationary value I.Therefore, bridge method inductance internal resistance measurement instrument exists Measuring Time to reach dozens of minutes to several hrs at present, and end of test (EOT) needs manual discharge, complicated operation, unsafe shortcoming.

The purpose of this utility model provides a kind of intelligent inductance internal resistance instrument for quick measuring.

The purpose of this utility model is achieved in that a kind of inductance internal resistance instrument for quick measuring; it is made up of display 1, microprocessor 2, variable constant current source 3, range differentiation, protection, discharge circuit 4, prime amplifier 5, A/D converter 6, and variable constant current source 3 and range differentiation, protection, discharge circuit 4 are respectively by I/O line x ₁～x ₄With I/O line y ₁～y ₆Connect with microprocessor 2, variable constant current source 3 has two output current line terminals B, C to meet Instrument shell electric current binding post K _I1, K _I2, variable constant current source 3 connects Instrument shell voltage binding post K by output current line terminals B and another outlet terminal A with incoming line terminal B ', the A ' of range differentiation, protection, discharge circuit 4 _U1, K _U2Meet two input voltage line terminals D, E of prime amplifier 5, prime amplifier 5 connects with microprocessor 2 through A/D converter 6, and microprocessor 2 connects display 1, wherein:

Variable constant current source 3 is by resistance R ₁₀₁, R ₁₀₆, divider resistance R ₁₀₂～R ₁₀₅, input resistance R ₁₀₇, R ₁₀₈, sampling resistor R ₁₀₉, R ₁₁₁, zinc paste overvoltage protection resistance R ₁₁₀, current-limiting resistance R ₁₁₂～R ₁₁₆, stabilivolt Z ₁₀₁, Z ₁₀₂, capacitor C ₁₀₁, potentiometer W ₁₀₁, analog switch SW ₁₀₁～SW ₁₀₄, operational amplifier A ₁₀₁, transistor T ₁₀₁, T ₁₀₂, relay J ₁, J ₂The contact form potentiometer W ₁₀₁, divider resistance string R ₁₀₂～R ₁₀₅With stabilivolt Z ₁₀₁Parallel connection, hot end passes through resistance R ₁₀₁With direct voltage source+V ₁Connect each photoelectrical coupler P of electronegative potential termination ₁₀₁～P ₁₀₄Emitter, analog switch SW ₁₀₁～SW ₁₀₄Input end be connected on potentiometer W respectively ₁₀₁, resistance R ₁₀₂～R ₁₀Between 5, analoging switch output end is through input resistance R ₁₀₇With operational amplifier A ₁₀₁In-phase end connect, the analog switch control end respectively with each photoelectrical coupler P ₁₀₁～P ₁₀₄Collector connect photoelectrical coupler P ₁₀₁～P ₁₀₄The anode of middle diode is respectively by corresponding current-limiting resistance R ₁₁₂～R ₁₁₅By I/O line X ₁～X ₄Connect its diode negativing ending grounding, resistance R with microprocessor ₁₀₆, capacitor C ₁₀₁, stabilivolt Z ₁₀₂The mu balanced circuit of forming, an end and DC voltage+V ₁Connect the other end and sampling resistor R ₁₀₉Be connected to photoelectrical coupler P altogether ₁₀₁～P ₁₀₄Emitter, sampling resistor R ₁₀₉The other end pass through resistance R ₁₀₈With operational amplifier A ₁₀₁End of oppisite phase connect operational amplifier A ₁₀₁Output termination current-limiting resistance R ₁₁₆, R ₁₁₆With the two triode T that connect ₁₀₁, T ₁₀₂Base stage connect T ₁₀₂Emitter be connected on resistance R ₁₀₉～R ₁₀₈Between, T ₁₀₁, T ₁₀₂Collector be connected to output current line terminals C, relay J ₁One of contact and DC voltage+V ₁Join, the other end is succeeded electrical equipment J respectively ₂Contact and resistance R ₁₁₁, relay J ₂The other end, contact be connected to output current line terminals C, resistance R ₁₁₁Another termination output current line terminals B, zinc paste overvoltage protection resistance R ₁₁₀Be connected across between output current line terminals B, C sampling resistor R ₁₁₁Double-end output current line terminals B connects with another outlet terminal A and range differentiation, protection, discharge circuit incoming line terminal B ', A ';

Range differentiation, protection, discharge circuit are by resistance R ₂₀₁, R ₂₀₂, R ₂₀₈, balance resistance R ₂₀₃, divider resistance R ₂₀₄～R ₂₀₇, operational amplifier A ₂₀₁, A ₂₀₂, comparer A ₂₀₃～A ₂₀₆, stabilivolt Z ₂₀₁, capacitor C ₂₀₁, potentiometer W ₂₀₁, drive amplifier transistor T ₂₀₁, T ₂₀₂, protection diode D ₂₀₁, D ₂02, relay J ₁, J ₂The line bag form operational amplifier A ₂₀₁The sub-A ' of homophase termination input wiring terminal, end of oppisite phase and output terminal short circuit, output terminal is through resistance R ₂₀₁Connect operational amplifier A ₂₀₂End of oppisite phase, operational amplifier A ₂₀₂Homophase termination balance resistance R ₂₀₃The back connects with the incoming line terminal B ' of ground connection, and end of oppisite phase and output terminal are connected to resistance R ₂₀₂, output terminal also with comparer A in parallel ₂₀₃～A ₂₀₆In-phase end connect comparer A ₂₀₃～A ₂₀₆End of oppisite phase between be connected to divider resistance R respectively ₂₀₄～R ₂₀₇, R ₂₀7 the sub-B ' of another termination input wiring terminal, output terminal is by I/O line y ₁～y ₄Connect DC voltage+V with microprocessor ₂Through resistance R ₂₀₈, stabilivolt Z ₂₀₁After the mu balanced circuit voltage stabilizing of forming, by potentiometer W ₂₀₁With comparer A ₂₀₃End of oppisite phase connect back-emf protection diode D ₂₀₁With relay J ₁The parallel connection of line bag, back-emf protection diode D ₂₀₂With relay J ₂The parallel connection of line bag, the hot end of two circuit and DC voltage+V ₂Connect, cold end connects respectively and drives amplifier transistor T ₂₀₁, T ₂₀₂Collector, transistor T ₂₀₁, T ₂₀₂Emitter meet incoming line terminal B ', base stage is by I/O line y ₅, y ₆Connect with microprocessor.

The utility model has the advantages that: the test duration is short, and is simple to operate, measures accurately, and end of test (EOT) does not need manual discharge, safe and reliable.

Fig. 1 is the circuit block diagram of the utility model embodiment and when using and extraneous tested inductance wiring schematic diagram.

Fig. 2 is variable constant current source circuit figure among the utility model embodiment.

Fig. 3 is range differentiation among the utility model embodiment, protection, discharge circuit figure.

Fig. 4 is the utility model embodiment panel figure.

Following adjoint is further done the explanation of embodiment:

As figure, the user presses the test external wiring way of Fig. 1, with tested inductance L _xTwo lines that respectively draw at two ends, a winding is to binding post K ₁₁, K ₁₂On, a winding is to binding post K _U1, K _U2On, open power switch device 4-2, press the initiating key 4-3 on the lower panel, microprocessor 2 sends the test commencing signal, and by programmed control, microprocessor 2 is by I/O line x ₄And y ₅Feed signals makes variable constant current source 3 send an electric current greater than 10A charge to tested inductance L x by output current line terminals B, C to variable constant current source 3 and range differentiation, protection, discharge circuit 4, and simultaneously, terminal A, B send voltage signal U from taking a sample _AbTo range differentiation, protection, discharge circuit 4, the signal of differentiating range is through I/O line y ₁～y ₄Deliver to microprocessor 2, behind microprocessor 2 selected ranges, by X ₁And X ₂Or X ₃Or X ₄Send the variable constant current source 3 that controls signal to, will deliver to output current line terminals B, C, be added on tested inductance L corresponding to the measurement continuous current 10A of selected range or 1A or 0.1A _xTwo ends cut off the charging current greater than 10A.Microprocessor will be at this moment from y ₂Or y ₃Or y ₄The sampled signal U of the electric current of sending here _AbReach the voltage signal U that tested inductance is sent here through preposition amplification, A/D converter _EdCalculate by voltammetry, draw the resistance value of tested inductance, and this value is delivered to display panel 4-1 demonstration, at this moment, the user can be by finishing strong 4-4, and microprocessor sends measures end signal through y ₅, y ₆Deliver to the protection discharge circuit, finish the discharge to tested inductance, it is bright that discharge finishes pilot lamp 4-5, promptly dismountable test external connection.

In variable constant current source shown in Figure 2, DC voltage+V ₁Through resistance R ₁₀₁, stabilivolt Z ₁₀₁After the voltage stabilizing, by potentiometer W ₁₀₁, divider resistance R ₁₀₂～R ₁₀₅Dividing potential drop, its branch pressure voltage value V fills, V10, V1, V0.1 measure constant current value corresponding to charging current value and 10A, 1A, 0.1A third gear greater than 10A successively, V10, V1, V0.1 are the benchmark voltage division signal, successively corresponding to 0～200 milliohm, 0～10 Europe, 0～100 Europe third gear range, be added in charging current on the tested inductance in resistance R ₁₁₁On signal U _AbDeliver to range differentiation, protection, discharge circuit 4 by terminal A, B and handle, again behind the selected range of microprocessor, through X ₂Or X ₃Or X ₄And X ₁SW with correspondence ₁₀₂～SW ₁₀₄One of open after, close SW ₁₀₁, with pairing benchmark voltage division signal through input resistance R ₁₀₇Send into operational amplifier A ₁₀₁In-phase end, output current is through sampling resistor R ₁₀₉Draw voltage signal through input resistance R ₁₀₈Insert operational amplifier A ₁₀₁End of oppisite phase, A ₁₀₁Benchmark voltage division signal and sampled signal are compared and enlarged, through resistance R ₁₁₆Current limliting, control triode T ₁₀₁, T ₁₀₂Conducting resistance, make output current be constant at setting value 10A or the 1A or the 0.1A of this range.Relay J ₁Whether the break-make of contact determines output current, relay J ₂Closure when tested inductance measurement finishes finishes the back in discharge and disconnects resistance R ₁₁₀Be zinc paste overvoltage protection resistance, it can prevent the attack of fortuitous event back-emf electric arc to circuit.

In range differentiation shown in Figure 3, protection, discharge circuit 4, between terminal A ', B ' voltage signal U _AbThrough A ₂₀₁Send into by A behind the follower that operational amplifier is formed ₂₀₂The amplifier that operational amplifier is formed, resistance R ₂₀₁, R ₂₀₂Ratio decision enlargement factor, R ₂₀₃Be balance resistance, the signal after the amplification inserts comparer A simultaneously ₂₀₃～A ₂₀₆In-phase input end.Through resistance R ₂₀₈, stabilivolt Z ₂₀₁Voltage stabilizing, burning voltage is through potentiometer W ₂₀₁, resistance R ₂₀₄～R ₂₀₇Dividing potential drop draw successively corresponding to 10A, 1A, 0.1A, and discharge finish four magnitudes of voltage of four kinds of different current values, insert A respectively ₂₀₃～A ₂₀₆The comparative voltage signal differentiated as range of inverting input and the abundant comparative voltage signal of discharge.A ₂₀3～A ₂₀₆Comparison output signal through I/O line y ₁～y ₄Send into microprocessor.

T ₂₀₁, T ₂₀₂Be relay J ₁, J ₂The driving amplifier transistor, D ₂₀₁, D ₂₀₂Be relay coil winding back-emf protection diode, T ₂₀₁, T ₂₀₂Base control signal by microprocessor through y ₅, y ₆Provide.

The technical indicator of this instrument is: measurement range: 0～100 ohm, measuring current: 0.1A, 1A, 10A show: 4 1/2, and range: 0～20 milliohm; 0～200 milliohm; 0～2 ohm; 0～10 ohm; 0～100 ohm, all select range automatically.

Claims (1)

1, a kind of inductance internal resistance instrument for quick measuring; it is made up of display 1, microprocessor 2, variable constant current source 3, range differentiation, protection, discharge circuit 4, prime amplifier 5, A/D converter 6, it is characterized in that: variable constant current source 3 and range differentiation, protection, discharge circuit 4 are respectively by 1/0 line X ₁～X ₄With 1/0 line y ₁～y ₆Connect with microprocessor 2, there are two output current line terminals B, C body contact body electric current binding post K in variable constant current source 3 ₁₁, K ₁₂, variable constant current source 3 connects housing voltage binding post K by output current line terminals B and another outlet terminal A with incoming line terminal B ', the A ' of range differentiation, protection, discharge circuit 4 _U1, K _U2Connect respectively on voltage input line terminal E, the D of prime amplifier 5, prime amplifier 5 connects with microprocessor 2 through A/D converter 6, and microprocessor 2 connects display 1, wherein:

Variable constant current source 3 is by resistance R ₁₀₁, R ₁₀₆, divider resistance R ₁₀₂～R ₁₀₅, input resistance R ₁₀₇, R ₁₀₈, sampling resistor R ₁₀₉, R ₁₁₁, zinc paste overvoltage protection resistance R ₁₁₀, current-limiting resistance R ₁₁₂～R ₁₁₆, stabilivolt Z ₁₀₁, Z ₁₀₂, capacitor C ₁₀₁, potentiometer W ₁₀₁, analog switch SW ₁₀₁～SW ₁₀4, operational amplifier A ₁₀₁, transistor T ₁₀₁, T ₁₀₂, relay J ₁, J ₂The contact form potentiometer W ₁₀₁, divider resistance string R ₁₀₂～R ₁₀₅With stabilivolt Z ₁₀₁Parallel connection, hot end passes through resistance R ₁₀₁With direct voltage source+V ₁Connect each photoelectrical coupler P of electronegative potential termination ₁₀₁～P ₁04 emitter, analog switch SW ₁₀₁～SW ₁₀₄Input end be connected on potentiometer W respectively ₁₀₁, resistance R ₁₀₂～R ₁₀₅Between, analoging switch output end is through input resistance R ₁₀₇With operational amplifier A ₁₀₁In-phase end connect, the analog switch control end respectively with each photoelectrical coupler P ₁₀₁～P ₁₀₄Collector connect photoelectrical coupler P ₁₀₁～P ₁₀₄The anode of middle diode is respectively by corresponding current-limiting resistance R ₁₁₂～R ₁₁₅By I/O line X ₁～X ₄Connect its diode negativing ending grounding, resistance R with microprocessor ₁₀₆, capacitor C ₁₀₁, stabilivolt Z ₁₀₂The mu balanced circuit of forming, an end and DC voltage+V ₁Connect the other end and sampling resistor R ₁₀₉Be connected to photoelectrical coupler P altogether ₁₀₁～P ₁₀₄Emitter, sampling resistor R ₁₀₉The other end pass through resistance R ₁₀₈With operational amplifier A ₁₀₁End of oppisite phase connect operational amplifier A ₁₀₁Output termination current-limiting resistance R ₁₁₆, R ₁₁₆With the two triode T that connect ₁₀₁, T ₁₀₂Base stage connect T ₁₀₂Emitter be connected on resistance R ₁₀₉～R ₁₀₈Between, T ₁₀₁, T ₁₀₂Collector be connected to output current line terminals C, relay J ₁One of contact and DC voltage+V ₁Join, the other end is succeeded electrical equipment J respectively ₂Contact and resistance R ₁₁₁, relay J ₂The other end, contact be connected to output current line terminals C, resistance R ₁₁₁Another termination output current line terminals B, zinc paste overvoltage protection resistance R ₁₁₀Be connected across between output current line terminals B, C sampling resistor R ₁₁₁Double-end output current line terminals B connects with another outlet terminal A and range differentiation, protection, discharge circuit incoming line terminal B ', A ';

Range differentiation, protection, discharge circuit are by resistance R ₂₀₁, R ₂₀₂, R ₂₀₈, balance resistance R ₂03, divider resistance R ₂₀₄～R ₂₀₇, operational amplifier A ₂₀₁, A ₂₀₂, comparer A ₂₀₃～A ₂₀₆, stabilivolt Z ₂₀₁, capacitor C ₂₀₁, potentiometer W ₂₀₁, drive amplifier transistor T ₂₀₁, R ₂₀₂, protection diode D ₂₀₁, D ₂₀₂, relay J ₁, J ₂The line bag form operational amplifier A ₂₀₁The sub-A ' of homophase termination input wiring terminal, end of oppisite phase and output terminal short circuit, output terminal is through resistance R ₂₀₁Connect operational amplifier A ₂₀₂End of oppisite phase, operational amplifier A ₂₀₂Homophase termination balance resistance R ₂₀₃The back connects with the incoming line terminal B ' of ground connection, and end of oppisite phase and output terminal are connected to resistance R ₂₀₂, output terminal also with comparer A in parallel ₂₀₃～A ₂₀₆In-phase end connect comparer A ₂₀₃～A ₂₀₆End of oppisite phase between be connected to divider resistance R respectively ₂₀₄～R ₂₀₇, R ₂₀₇The sub-B ' of another termination input wiring terminal, output terminal is by I/O line y ₁～y ₄Connect DC voltage+V with microprocessor ₂Through resistance R ₂₀₈, stabilivolt Z ₂₀₁After the mu balanced circuit voltage stabilizing of forming, by potentiometer W ₂₀₁With comparer A ₂₀₃End of oppisite phase connect back-emf protection diode D ₂₀₁With relay J ₁The parallel connection of line bag, back-emf protection diode D ₂₀₂With relay J ₂The parallel connection of line bag, the hot end of two circuit and DC voltage+V ₂Connect, cold end connects respectively and drives amplifier transistor T ₂₀₁, T ₂₀₂Collector, transistor T ₂₀₁, T ₂₀₂Emitter meet incoming line terminal B ', base stage is by I/O line y ₅, y ₆Connect with microprocessor.

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