CN204065214U - There is the voltage measuring apparatus of five step discs - Google Patents

Abstract

A kind of voltage measuring apparatus having five step discs for DC voltage measurement, wherein its four step discs below are all coiled by measurement and the replacement dish identical with measurement dish structure forms, four step disc measurement dishes next and the corresponding contact on replacement dish are connected to each other on rear three step discs does not all have resistance, and it makes voltage measuring apparatus inner lead resistance, switch contact resistance and variation, thermoelectrical potential can both be ignored voltage measuring apparatus impact.

Description

There is the voltage measuring apparatus of five step discs

Technical field

The present invention relates to the instrument that DC voltage is measured.

Background technology

The current voltage measuring apparatus for there being five step discs, in the connection between five step discs, telophragma generally adopts switching over, so just produces the variation of contact resistance, brings restriction to resolution.In order to overcome this problem, the large brush of general employing with enlarge active surface, and adopts silver-carbon/carbon-copper composite material; The new method that the voltage measuring apparatus solution switch contact resistance that application number 200810121911.4 discloses five step discs is deteriorated, its five step discs are all coiled by measurement and replacement dish forms, not containing bracket panel, each measurement dish and replacement dish there is resistance, measurement dish on its five step discs and replacement dish constitute bridge circuit in circuit, its maximum defect is that error is not independent, once measurement coil certain some indicating value overproof, just cannot to determine which resistance is overproof to cause, this makes troubles to qualification and maintenance.

Summary of the invention

The object of the invention is to design a kind of voltage measuring apparatus having five step discs, it does not adopt bridge circuit, and such error can be independent, and does not have resistance between rear three step disc contacts, and this can reduce costs, and reduces instrument volume.

Technical scheme of the present invention is taked like this: voltage measuring apparatus is from the external working power E positive pole terminal adjustable resistance R through 22 4 Ω resistant series be made up of of range of adjustment between 2.1 ~ 3V _p1, the adjustable resistance R to be made up of 21 0.2 Ω resistant series _p2, and the adjustable resistance R of range of adjustment between 0 ~ 0.22 Ω _p3, through five step discs, set up resistance R to 1018 Ω _n, then get back to the external working power E negative pole terminal composition voltage measuring apparatus performance loop of range of adjustment between 2.1 ~ 3V through 18 × 0.05 Ω temperature compensation dish W, from external saturated standard cell E _npositive pole terminal is connected to the double-point double-throw switch K of galvanometer G between two normally closed contacts ₂resistance R is set up to 1018 Ω _nagain through having the temperature compensation dish W of 18 × 0.05 Ω resistance in seriess to get back to external saturated standard cell E above _nnegative pole terminal composition voltage measuring apparatus standard loop, for connecting measured " U _x" two terminals, positive pole terminal after five measurement dishes, then is connected to the double-point double-throw switch K of galvanometer G between two normally closed contacts ₂to negative pole terminal composition voltage measuring apparatus equalizing network, it is characterized in that the first step disc has 0, 1, 2, the measurement dish I of 20 totally 21 gears, measurement dish I welds 0.1 Ω resistance one between every two adjacent contacts, and the second step disc is by having 0, 1, 2, 10 totally 11 gears measurement dish II with have 0, 1, 2, the replacement dish II ' composition of 10 totally 11 gears, the resistance one that resistance is 0.1 Ω is welded between measurement dish II with upper every two adjacent contacts of replacement dish II ', " 0 " contact of measurement dish II is circuit node A, " 10 " contact of replacement dish II ' is circuit node B, and the 3rd step disc is by having 0, 1, 2, 10 totally 11 gears measurement dish III with have 0, 1, 2, the replacement dish III ' composition of 10 totally 11 gears, the 4th step disc is by having 0, 1, 2, 10 totally 11 gears measurement dish IV with have 0, 1, 2, the replacement dish IV ' composition of 10 totally 11 gears, the 5th step disc is by having 0, 1, 2, 10 totally 11 gears measurement dish V with have 0, 1, 2, the replacement dish V ' composition of 10 totally 11 gears, each contact in 3rd step disc on measurement dish III and replacement dish III ', each contact in 4th step disc on measurement dish IV and replacement dish IV ', each contact in 5th step disc on measurement dish V and replacement dish V ', be connected with the corresponding contact of replacement dish II ' with measurement dish II in the second step disc, the Metal Contact ring of the second step disc measurement dish II and the Metal Contact interannular of the replacement dish IV ' resistance R of 999 Ω ₁connect, the Metal Contact ring of the 3rd step disc measurement dish III and the Metal Contact interannular of the replacement dish III ' resistance R of 9999 Ω ₂connect, the Metal Contact ring of the 4th step disc measurement dish IV and the Metal Contact interannular of the replacement dish IV ' resistance R of 100K Ω ₃connect, the Metal Contact ring of the 5th step disc measurement dish V and the Metal Contact interannular of the replacement dish V ' resistance R of 1000K Ω ₄connect, synchronous when the brush on each step disc measurement dish rotates with the brush on replacement dish, " 0 " contact of measurement dish II and node A connect measurement dish I " 0 " contact, and measurement dish I " 20 " contact connects adjustable resistance R through node C _p3cold end, another road of node C is through 102 Ω resistance R ₆connect single-pole double-throw switch (SPDT) K ₁in × 0.1 range contact, " 10 " contact of replacement dish I ' and circuit node B connect single-pole double-throw switch (SPDT) K ₁in × 1 range contact, then through 918 Ω resistance R ₇connect single-pole double-throw switch (SPDT) K ₁in × 0.1 range contact, by 112.4986 Ω resistance R between node A and Node B ₅connect, single-pole double-throw switch (SPDT) K ₁in normally closed contact connect 1018 Ω and set up resistance R _nhot end, 1018 Ω set up resistance R _nbe connected with " 0 " contact of the temperature compensation dish W of 18 × 0.05 Ω resistance in seriess, 1018 Ω set up resistance R _nhot end 101.89 Ω resistance Rs in parallel with " 18 " two ends, contact of temperature compensation dish W ₈external working power E negative pole terminal between rear connection 2.1 ~ 3V, for connecting measured " U _x" two measure terminals, positive pole terminal is connected with the Metal Contact ring of measurement dish I, and negative pole terminal is connected to the double-point double-throw switch K of galvanometer G between two normally closed contacts ₂be connected with " 10 " contact of measurement dish II afterwards.

By above technical scheme, between the 3rd, the 4th, the 5th step disc contact, all there is no resistance, and five step disc errors are independent, the error of the identical stepping of rear four dish is consistent, and this brings convenience to debugging and maintenance, also makes voltage measuring apparatus structure simple, volume-diminished, thus reduce production cost; When voltage measuring apparatus five measurement dish resets, the internal wiring combined potential of voltage measuring apparatus is A point current potential, some current potentials are " 0 ", so the zero potential of this voltage measuring apparatus is very little, the thermoelectrical potential of rear five several μ V of each branch road of step disc is all connected in the voltage drop in units of lying prostrate, and therefore thermoelectrical potential is to " U _x" two measure terminals impact can ignore.

Accompanying drawing explanation

Fig. 1 is a kind of schematic circuit of the present invention.

In FIG, the adjustable resistance R of 22 × 4 Ω _p1, represent adjustable resistance R _p1on have 22 resistances to be resistant series of 4 Ω, in like manner, the adjustable resistance R of 21 × 0.2 Ω _p2, represent adjustable resistance R _p2on have 21 resistances to be resistant series of 0.2 Ω, 20 × 0.1 Ω on first step disc measurement dish I represent that measurement dish I has 20 resistances to be resistant series of 0.1 Ω, 10 × 0.1 Ω on second step disc measurement dish II and replacement dish II ', represent and measurement dish II and replacement dish II ' has 10 resistances to be resistant series of 0.1 Ω, in FIG, on step disc, thick black line represents Metal Contact ring, and hollow small circle represents hard contact, and four-headed arrow represents metallic brush.

Embodiment

Embodiment 1, in FIG, when in rear four step discs between node A, Node B, any one step disc rotates, the resistance that electric current flows through measurement dish to be increased equals the resistance that electric current flows through the minimizing of replacement dish, vice versa, so, what indicating value no matter rear four step discs put, and this step disc resistance value between node A and Node B is constant, and this can ensure what indicating value no matter rear four step discs put, each step disc resistance ratio is substantially constant, also ensures that the electric current flowing through each step disc is substantially constant.

Voltage measuring apparatus standard operation current design becomes 11mA, when × 1 range, is 102 Ω, from node C through resistance R from node C through five step discs to Node B resistance ₆, resistance R ₇be 1020 Ω to Node B resistance, so 10mA working current flows through five step discs, 1mA working current flows through resistance R ₆, resistance R ₇; When × 0.1 range, be 102 Ωs through five step discs to Node B resistance from node C, connect 918 Ω resistance R ₇after resistance be 1020 Ω, so 1mA working current flows through five step discs, 10mA working current flows through resistance R ₆.

When × 1 range, voltage measuring apparatus 10mA working current is divided into five tunnels after node A: a road is through measurement dish II, and a road is through measurement dish III, and a road is through measurement dish IV, and a road is through measurement dish V, then a road is through 112.4986 Ω resistance R ₅, five road electric currents meet at Node B.Remove through resistance R ₅outside branch road, each branch resistance ratio between node A, Node B: the 5th step disc: the 4th stepping: the 3rd step disc: the second step disc=1000: 100: 10: 1, so, except flowing through resistance R ₅outside branch road, flowing through each branch current ratio between node A, Node B is: the 5th step disc: the 4th stepping: the 3rd step disc: the second step disc=1: 10: 100: 1000, except resistance R ₅outside branch road, between node A, Node B, resistance is 1000K Ω/1111, allow flow through measurement dish V, the total current of measurement dish IV, measurement dish III and measurement dish II is 1.111mA, flows through resistance R ₅electric current be 8.889mA, then 8.889mA × R ₅=1000K Ω/1111 × 1.111mA, resistance R ₅≈ 112.4986 Ω.Voltage measuring apparatus 10mA working current is through resistance R ₅shunting, making to flow through measurement dish V electric current is 0.001mA, and measurement dish IV electric current is 0.01mA, and measurement dish III is 0.1mA, and measurement dish II electric current is 1mA; At this moment each stepping of the first step disc is 1mV, and each stepping of the second step disc is 0.1mV, and each stepping of the 3rd step disc is 0.01mV, and each stepping of the 4th step disc is 0.001mV, and each stepping of the 5th step disc is 0.0001mV.

When after working current standardization, n thrown by I measurement dish ₁, n thrown by II measurement dish ₂, n thrown by III measurement dish ₃, n thrown by IV measurement dish ₄, n thrown by V measurement dish ₅, K switch is thrown to the left side, and between two terminals being at this moment positioned at measurement, voltage is:

U _X＝10×0.1n ₁+1×0.1n ₂+0.1×0.1n ₃+0.01×0.1n ₄+0.001×0.1n ₅(mV)

U _X＝1n ₁+0.1n ₂+0.01n ₃+0.001n ₄+0.0001n ₅(mV)

U _X＝1000n ₁+100n ₂+10n ₃+1n ₄+0.1n ₅(μV)

When × 0.1 range, the electric current flowing through five measurement dishes is reduced to when × 1 range 1/10, so when after working current standardization, n thrown by I measurement dish ₁, n thrown by II measurement dish ₂, n thrown by III measurement dish ₃, n thrown by IV measurement dish ₄, n thrown by V measurement dish ₅, K switch is thrown to the left side, and between two terminals being at this moment positioned at measurement, voltage is:

U _X＝1×0.1n ₁+0.1×0.1n ₂+0.01×0.1n ₃+0.001×0.1n ₄+0.0001×0.1n ₅(mV)

U _X＝100n ₁+10n ₂+1n ₃+0.1n ₄+0.01n ₅(μV)

Voltage measuring apparatus working power will adopt YJ49 type high stability adjustable stabilized voltage supply, adjustable resistance R _p1, adjustable resistance R _p2, adjustable resistance R _p3for regulating working current, adjustable resistance R _p3the resistance value of whole range of adjustment is greater than adjustable resistance R _p2a step value, adjustable resistance R _p2the resistance value of whole range of adjustment is greater than adjustable resistance R _p1a step value, as long as YJ49 type high stability adjustable stabilized voltage supply output voltage is adjusted between 2.1 ~ 3V, just can conveniently by regulating adjustable resistance R _p1, adjustable resistance R _p2, adjustable resistance R _p3voltage measuring apparatus working current is adjusted to standard state.

In standard loop, the electromotive force of saturated standard cell is 1.0186V when room temperature 20 DEG C, environment temperature often raises 1 DEG C, and the electromotive force of saturated standard cell reduces about 40 μ V, determines by the thermometer of 0.1 DEG C of resolution on saturated standard cell the electromotive force that saturated standard cell is instant.This voltage measuring apparatus temperature compensation dish of every stepping 50 μ V compensates temperature.

Claims (1)

1. have a voltage measuring apparatus for five step discs, voltage measuring apparatus is from the external working power E positive pole terminal adjustable resistance R through 22 4 Ω resistant series be made up of of range of adjustment between 2.1 ~ 3V _p1, the adjustable resistance R to be made up of 21 0.2 Ω resistant series _p2, and the adjustable resistance R of range of adjustment between 0 ~ 0.22 Ω _p3, through five step discs, set up resistance R to 1018 Ω _n, then get back to the external working power E negative pole terminal composition voltage measuring apparatus performance loop of range of adjustment between 2.1 ~ 3V through 18 × 0.05 Ω temperature compensation dish W, from external saturated standard cell E _npositive pole terminal is connected to the double-point double-throw switch K of galvanometer G between two normally closed contacts ₂resistance R is set up to 1018 Ω _nagain through having the temperature compensation dish W of 18 × 0.05 Ω resistance in seriess to get back to external saturated standard cell E above _nnegative pole terminal composition voltage measuring apparatus standard loop, for connecting measured " U _x" two terminals, positive pole terminal after five measurement dishes, then is connected to the double-point double-throw switch K of galvanometer G between two normally closed contacts ₂to negative pole terminal composition voltage measuring apparatus equalizing network, it is characterized in that the first step disc has 0, 1, 2, the measurement dish I of 20 totally 21 gears, measurement dish I welds 0.1 Ω resistance one between every two adjacent contacts, and the second step disc is by having 0, 1, 2, 10 totally 11 gears measurement dish II with have 0, 1, 2, the replacement dish II ' composition of 10 totally 11 gears, the resistance one that resistance is 0.1 Ω is welded between measurement dish II with upper every two adjacent contacts of replacement dish II ', " 0 " contact of measurement dish II is circuit node A, " 10 " contact of replacement dish II ' is circuit node B, and the 3rd step disc is by having 0, 1, 2, 10 totally 11 gears measurement dish III with have 0, 1, 2, the replacement dish III ' composition of 10 totally 11 gears, the 4th step disc is by having 0, 1, 2, 10 totally 11 gears measurement dish IV with have 0, 1, 2, the replacement dish IV ' composition of 10 totally 11 gears, the 5th step disc is by having 0, 1, 2, 10 totally 11 gears measurement dish V with have 0, 1, 2, the replacement dish V ' composition of 10 totally 11 gears, each contact in 3rd step disc on measurement dish III and replacement dish III ', each contact in 4th step disc on measurement dish IV and replacement dish IV ', each contact in 5th step disc on measurement dish V and replacement dish V ', be connected with the corresponding contact of replacement dish II ' with measurement dish II in the second step disc, the Metal Contact ring of the second step disc measurement dish II and the Metal Contact interannular of the replacement dish II ' resistance R of 999 Ω ₁connect, the Metal Contact ring of the 3rd step disc measurement dish III and the Metal Contact interannular of the replacement dish III ' resistance R of 9999 Ω ₂connect, the Metal Contact ring of the 4th step disc measurement dish IV and the Metal Contact interannular of the replacement dish IV ' resistance R of 100K Ω ₃connect, the Metal Contact ring of the 5th step disc measurement dish V and the Metal Contact interannular of the replacement dish V ' resistance R of 1000K Ω ₄connect, synchronous when the brush on each step disc measurement dish rotates with the brush on replacement dish, " 0 " contact of measurement dish II and node A connect measurement dish I " 0 " contact, and measurement dish I " 20 " contact connects adjustable resistance R through node C _p3cold end, another road of node C is through 102 Ω resistance R ₆connect single-pole double-throw switch (SPDT) K ₁in × 0.1 range contact, " 10 " contact of replacement dish I ' and circuit node B connect single-pole double-throw switch (SPDT) K ₁in × 1 range contact, then through 918 Ω resistance R ₇connect single-pole double-throw switch (SPDT) K ₁in × 0.1 range contact, by 112.4986 Ω resistance R between node A and Node B ₅connect, single-pole double-throw switch (SPDT) K ₁in normally closed contact connect 1018 Ω and set up resistance R _nhot end, sets up resistance R at 1018 Ω _nthe 101.89 Ω resistance R in parallel of the two ends after the temperature compensation dish W of 18 × 0.05 Ω resistance in seriess are had above connection ₈external working power E negative pole terminal between rear connection 2 ~ 3V, for connecting measured " U _x" two measure terminals, positive pole terminal is connected with the Metal Contact ring of measurement dish I, and negative pole terminal is connected to the double-point double-throw switch K of galvanometer G between two normally closed contacts ₂be connected with " 10 " contact of measurement dish II afterwards.