CN2304130Y

CN2304130Y - D. C. resistance detecting instrument

Info

Publication number: CN2304130Y
Application number: CN 97236561
Authority: CN
Inventors: 沈治
Original assignee: Individual
Current assignee: Individual
Priority date: 1997-07-15
Filing date: 1997-07-15
Publication date: 1999-01-13
Anticipated expiration: 2007-07-15

Abstract

The utility model discloses a DC resistance detecting instrument which relates to a detecting instrument used for measuring the conductor resistance values of various conductors and semiconductors and contact resistance values between conductors. The structure of the utility model comprises a box body, an upper cover, a panel, an electronic circuit with a power supply, a control circuit 1, a control circuit 2, a current generator measuring circuit and a measurement displaying circuit, wherein, the current generator measuring circuit is composed of an operational amplifier IC< 1 >, a resistor R< 1 >, a current amplifying transistor set, a four-terminal chucking appliance, a measured resistor RX, a measurement mode converter, a scaling resistor RS, power supplies E< 1 > and E< 2 >, a power charging jack Z and a potentiometer W< 2 > for an isolating diode D< 10 >. The measurement displaying circuit is composed of a double-integrating type analog-to-digital converter IC< 2 >, the voltage end of the four-terminal chucking appliance, resistors R< 2 >-R< 7 >, a potentiometer W< 1 >, capacitors C< 1 >-C< 5 >, diodes D< 1 > and D< 2 >, constant voltage diodes DW< 1 > and DW< 2 > and a DC power supply E< 3 >.

Description

The direct current resistance detector

What the utility model direct current resistance detector related to is a kind of detecting instrument that is used to measure the contact resistance value between various conductors and semi-conductive conductor resistance value and conductor.

Domestic and international existing direct current resistance measurer device generally adopts ac power supply method that civil power is become direct current after the transformer rectification and puts on the testing resistance, carry out the measurement of resistance again, its shortcoming is a, must is supplied to the field condition measurement to make troubles by electric main when measuring, b, Alternating Current Power Supply disturb influences measuring accuracy greatly, c, owing to introduce the electric main current potential, disturb occasion at highfields such as transformer stations, can damage instrument because of interference voltage, d, the high circuit complexity of Alternating Current Power Supply cost, volume is gained in weight unfavorable portable greatly.Instrument all adopts the constant current metering system at present, promptly when measuring, be added in a constant DC on the measured resistance for a long time, will produce a lot of heats like this and the measured resistance temperature is raise, and a lot of resistance varies with temperature and changes, this is the accuracy of influence measurement just.The instrument great majority do not possess temperature compensation function both at home and abroad at present, are that circuit is loaded down with trivial details even this function is arranged yet, and compensation precision is poor.The anti-strong-electromagnetic field interference performance of existing in addition direct current resistance measurer device is poor, uses cisco unity malfunction in highfield environment such as operation transformer station, even makes instrument damage.

The purpose of this utility model is the direct current resistance measurer that a kind of novelty is provided at the weak point that present direct current resistance measurer exists, instrument all adopts battery direct current supply, apparatus structure is simplified, light, portable, save cost, reliability and antijamming capability have been improved, the measuring instrument circuit has the current feedback circuit of measurement circuit, measure display circuit, control circuit adopts the impulse current measurement method during measurement, measured resistance is applied of short duration pulse direct current, make the measured resistance thermal value little, temperature rise is low, has improved measuring accuracy, and have " routine measurement " and " temperature compensation " two kinds of working methods, can not measured ambient temperature effect.Instrument has interference free performance, can disturb on-the-spot operate as normal at strong-electromagnetic field.

The direct current resistance detector takes following scheme to realize: direct current resistance detector structure has the detector cabinet, cabinet is made of casing, loam cake, the panel of direct current resistance detector is housed on the casing, the charger socket is housed on panel, charging indicator light, the I/U selector switch, the calibration adjustments hole, current terminal binding post I+, voltage end binding post U+, voltage end binding post V-, current terminal binding post I-, resistance display screen, I/U display screen, measurement pilot lamp, measurement button, power check button, power switch, metering system converter.Box house is equipped with direct current resistance detector circuit board, battery and electronic line component.Direct current resistance detector electronic circuit is by power supply E ₁, E ₂, E ₃, measure the current feedback circuit circuit, measure display circuit, control circuit 1, control circuit 2 is formed.Power supply E ₁, E ₂, E ₃All adopt battery.

Measure the current feedback circuit circuit by operational amplifier IC ₁, resistance R ₁, electric current amplifier transistor group, four terminal anchor clamps I+, I-, measured resistance RX, metering system converter K ₁, K ₂, K ₃, calibration resistance R S, power supply E ₁, E ₂, charging socket Z, isolating diode D ₁₀Potentiometer W ₂Constitute.Operational amplifier IC ₁1 pin be the output terminal of homophase termination controller circuitry 1, IC ₁2 pin be that the backward end of amplifier is through K ₂S links to each other IC with the calibration resistance R ₁Output terminal 5 through resistance R ₁Link to each other with electric current amplifier transistor group first order transistor base, first order emitter links to each other with second level transistor base, and second level emitter is connected to the transistorized base stage of the third level, and the collector of triode transistor connects together and is connected to accumulator E ₁Positive pole, the triode transistor emitter adopts four terminal connections to link to each other with measured resistance, through K ₁Adopt four terminal connections to receive calibration resistance R S again, the accumulator negative terminal is through K ₃Link to each other with calibration resistance R S lower end.IC ₁3 termination battery E ₂Anode, IC ₁4 termination battery E ₂Negative terminal,

IC

₁6,7 indirect potentiometer W ₂, W ₂Adjusting termination E ₂Negative pole.

Measure display circuit by double integral modulus converter IC ₂, four terminal chucking voltage end V+, V-resistance R ₂, R ₃, R ₄, R ₅, R ₆, R ₇, potentiometer W ₁, capacitor C ₁, C ₂, C ₃, C ₄, C ₅, diode D ₁, D ₂, voltage stabilizing diode DW ₁, DW ₂, direct supply E ₃Constitute, wherein R ₂, R ₃, D ₁, D ₂, R ₄, C ₁, DW ₁, DW ₂Constitute anti-strong-electromagnetic field interference protection circuit.Four terminal anchor clamps binding post voltage end V+ are connected to resistance R ₃, R ₃Be connected to diode D again ₂Positive pole, D ₂Positive pole and diode D ₁Negative pole link to each other, be connected to IC again ₂ Input end 30, IC ₂Input end 30 be connected to capacitor C ₁, C ₁The other end be connected to IC ₂Another input end 31, four another voltage end of terminal connections post V-be connected to resistance R ₂, R ₂The other end is connected to D ₂Negative pole and D ₁Positive pole, be connected to R again ₄, R ₄The other end and IC ₂Input end 31 link to each other IC ₂30 ends and IC ₂Simulation common port 32 ends link to each other power supply E ₃Positive pole and IC ₂Power positive end 35 link to each other power supply E ₃Negative terminal and IC ₂Power supply negative terminal 26 join IC ₂35 termination voltage stabilizing diode DW ₁Negative pole, and IC ₂26 termination voltage stabilizing diode DW ₁Positive pole, 35 are connected to resistance R ₅, R ₅Be connected to potentiometer W ₁, W ₁The other end be connected to IC ₂

Reference voltage anode

36,36 ends are connected to R again ₆, R ₆The other end is connected to IC ₂32 ends, IC ₂32 be connected to voltage stabilizing diode DW ₂Positive pole, and DW ₂Negative pole be connected to IC ₂35 ends.IC ₂33,34 ends between connect capacitor C ₂, IC ₂39 terminating resistor R ₉, R ₉Another termination IC ₂40 ends, IC ₂40 termination capacitor C ₅, C ₅Another termination IC ₂38 ends, C ₃, R ₈, C ₄The end C that links to each other ₃Another termination IC ₂27 ends, R ₈The other end be connected to IC ₂28 ends, C ₄The other end be connected to IC ₂29 ends, control circuit 2 output terminals and IC ₂1 end join.

The direct current resistance detector is owing to all adopt battery direct current supply to make designs simplification, instrument is light, save cost and improved reliability and antijamming capability,, be particularly suitable for portable extremely on-the-spot the use owing to do not need the ac power supply restriction, when measuring, adopt the impulse current measurement method, measured resistance is applied of short duration pulse direct current, make the measured resistance thermal value little, temperature rise is low, improve measuring accuracy, and reduced electrical source consumption.This instrument has " routine measurement " and " temperature compensation " two kinds of working methods, when the routine measurement mode is worked, the resistance that records is measured resistance resistance at room temperature, its result is the resistance under specified temp and is not subjected to the influence of measures ambient temperature when the temperature compensation working method, instrument has unique interference free performance to can be used on the occasion that strong-electromagnetic field disturbs, as on-the-spot detection of 500KV operation transformer station, accuracy of reading does not damage instrument.Contact resistance value, its measurement range that this detector is used to measure between various conductors and semi-conductive resistance value and conductor can be from 20 kilo-ohms to 0.1 micro-ohms, can be used for the electrical engineering and electric apparatus industry and measure the resistance value of conductor and mutual contact resistance value, carry out quality inspection control, also can be used in power department such as the transformer station the primary cut-out high voltage isolator, current transformer, its contact resistance of testing of equipments such as bus and loop resistance, also can be used on mechanical industry, come indirect detection machinery parameters by measurement, carry out quality inspection resistance.

The utility model is described in further detail below with reference to accompanying drawing.

Fig. 1 is a direct current resistance detector synoptic diagram.

Fig. 2 is that the direct current resistance detector is measured the current feedback circuit circuit theory diagrams.

Fig. 3 is that the direct current resistance detector is measured the display circuit schematic diagram.

Has the detector cabinet with reference to accompanying drawing 1 direct current resistance detector structure, cabinet is made of box cover, the panel of direct current resistance detector is housed on the casing, charger socket (1) is housed on panel, charging indicator light (2), I/U selector switch (3), calibration adjustments hole (4), current terminal binding post I+ (5), voltage end binding post U+ (6), voltage end binding post V-(7), current terminal binding post I-(8), resistance display screen (9), I/U display screen (10), measure pilot lamp (11), measure button (12), power check button (13), power switch (14), metering system converter (15).Box house is equipped with direct current resistance detector circuit board, battery and electronic line component.Direct current resistance detector electronic circuit is by power supply E ₁, E ₂, E ₃, measure the current feedback circuit circuit, measure display circuit, control circuit 1, control circuit 2 is formed.E ₁, E ₂, E ₃All adopt battery.E ₁Can adopt 12 volts maintenance-free lead accumulator or cadmium-nickel accumulator, nickel-hydrogen accumulator, control circuit 1, control circuit 2 are pulse-generator circuit.

Measure the current feedback circuit circuit by operational amplifier IC ₁, resistance R ₁, electric current amplifier transistor group, four terminal anchor clamps I+, I-, measured resistance RX, metering system converter K ₁, K ₂, K ₃, calibration resistance R S, power supply E ₁, E ₂, charging socket Z, isolating diode D ₁₀Potentiometer W ₂Constitute.Operational amplifier IC ₁1 pin be the output terminal of homophase termination controller circuitry 1, IC ₁2 pin be that the backward end of amplifier is through K ₂S links to each other IC with the calibration resistance R ₁Output terminal 5 through resistance R ₁Link to each other with electric current amplifier transistor group first order transistor base, first order emitter links to each other with second level transistor base, and second level emitter is connected to the transistorized base stage of the third level, and three grades of transistorized collectors connect together and are connected to accumulator E ₁Positive pole, third level emitter adopts four terminal connections to link to each other with measured resistance, through K ₁Adopt four terminal connections to receive calibration resistance R S again, the accumulator negative terminal is through K ₃Link to each other with calibration resistance R S lower end.IC ₁3 termination battery E ₂Anode, IC ₁4 termination battery E ₂Negative terminal,

IC

₁6,7 indirect potentiometer W ₂, W ₂Adjusting termination E ₂Negative pole.Operational amplifier IC ₁Can adopt CA3140,358 integrated packages.

Reference voltage anode

36,36 ends are connected to R again ₆, R ₆The other end is connected to IC ₂32 ends, IC ₂32 be connected to voltage stabilizing diode DW ₂Positive pole, and DW ₂Negative pole be connected to IC ₂35 ends.IC ₂33,34 ends between connect capacitor C ₂, IC ₂39 terminating resistor R ₉, R ₉Another termination IC ₂40 ends, IC ₂40 termination capacitor C ₅, C ₅Another termination IC ₂38 ends, C ₃, R ₈, C ₄The end C that links to each other ₃Another termination IC ₂27 ends, R ₈The other end be connected to IC ₂28 ends, C ₄The other end be connected to IC ₂29 ends, control circuit 2 output and IC ₂1 end join.

Claims

1, a kind of direct current resistance detector, have the detector cabinet, cabinet has casing, loam cake, the panel of direct current resistance detector is housed on the casing, box house is equipped with direct current resistance detector circuit board, power supply and electronic line component, electronic circuit has power supply, control circuit 1, control circuit 2, it is characterized in that electronic circuit also has the current feedback circuit of measurement circuit, measures display circuit; Measure the current feedback circuit circuit by operational amplifier IC ₁, resistance R ₁, electric current amplifier transistor group, four terminal anchor clamps I+, I-, measured resistance RX, metering system converter K ₁, K ₂, K ₃, calibration resistance R S, power supply E ₁, E ₂, charging socket E, isolating diode D ₁₀Potentiometer W ₂Constitute operational amplifier IC ₁1 pin be the output terminal of in-phase end connection control circuit 1, IC ₁2 pin be that the backward end of amplifier is through K ₂S links to each other IC with the calibration resistance R ₁Output terminal 5 through resistance R ₁Link to each other with electric current amplifier transistor group first order transistor base, first order emitter links to each other with second level transistor base, and second level emitter is connected to the transistorized base stage of the third level, and the collector of triode transistor connects together and is connected to accumulator E ₁Positive pole, the triode transistor emitter adopts four terminal connections to link to each other with measured resistance, through K ₁Adopt four terminal connections to receive calibration resistance R S again, the accumulator negative terminal is through K ₃Link to each other IC with calibration resistance R S lower end ₁3 termination battery E ₂Anode, IC ₁4 termination battery E ₂Negative terminal, IC ₁6,7 indirect potentiometer W ₂, W ₂Adjusting termination E ₂Negative pole; Measure display circuit by double integral modulus converter IC ₂, four terminal chucking voltage end V+, V-resistance R ₂, R ₃, R ₄, R ₅, R ₆, R ₇, potentiometer W ₁, capacitor C ₁, C ₂, C ₃, C ₄, C ₅, diode D ₁, D ₂, voltage stabilizing diode DW ₁, DW ₂, direct supply E ₃Constitute, wherein R ₂, R ₃, D ₁, D ₂, R ₄, C ₁, DW ₁, DW ₂Constitute anti-strong-electromagnetic field interference protection circuit.Four terminal anchor clamps binding post voltage end V+ are connected to resistance R ₃, R ₃Be connected to diode D again ₂Positive pole, D ₂Positive pole and diode D ₁Negative pole link to each other, be connected to IC again ₂Input end 30, IC ₂Input end 30 be connected to capacitor C ₁, C ₁The other end be connected to IC ₂Another input end 31, four another voltage end of terminal connections post V-be connected to resistance R ₂, R ₂The other end is connected to D ₂Negative pole and D ₁Positive pole, be connected to R again ₄, R ₄The other end and IC ₂Input end 31 link to each other IC ₂30 ends and IC ₂Simulation common port 32 ends link to each other power supply E ₃Positive pole and IC ₂Power positive end 35 link to each other power supply E ₃Negative terminal and IC ₂Power supply negative terminal 26 join IC ₂35 termination voltage stabilizing diode DW ₁Negative pole, and IC ₂26 termination voltage stabilizing diode DW ₁Positive pole, 35 are connected to resistance R ₅, R ₅Be connected to potentiometer W ₁, W ₁The other end be connected to IC ₂Reference voltage anode 36,36 ends are connected to R again ₆, R ₆The other end is connected to IC ₂32 ends, IC ₂32 be connected to voltage stabilizing diode DW ₂Positive pole, and DW ₂Negative pole be connected to IC ₂35 ends.IC ₂33,34 ends between connect capacitor C ₂, IC ₂39 terminating resistor R ₉, R ₉Another termination IC ₂40 ends, IC ₂40 termination capacitor C ₅, C ₅Another termination IC ₂38 ends, C ₃, R ₈, C ₄The end C that links to each other ₃Another termination IC ₂27 ends, R ₈The other end be connected to IC ₂28 ends, C ₄The other end be connected to IC ₂29 ends, control circuit 2 output terminals and IC ₂1 end join.

2, direct current resistance detector according to claim 1 is characterized in that power supply E ₁, E ₂, E ₃All adopt battery.

3, according to claim 1,2 described direct current resistance detectors, it is characterized in that power supply E ₁Adopt maintenance-free lead accumulator or cadmium-nickel accumulator, nickel-hydrogen accumulator.

4, direct current resistance detector according to claim 1, it is characterized in that on panel, being equipped with the charger socket, charging indicator light, I/U selector switch, calibration adjustments hole, current terminal binding post, voltage end binding post, resistance display screen, I/U display screen, measurement pilot lamp, measurement button, power check button, power switch, metering system converter.