CN204044218U - Be the pressure measuring instrument of power supply with dry cell - Google Patents

Abstract

A kind of is the pressure measuring instrument of power supply for DC voltage measurement dry cell, 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 pressure measuring instrument inner lead resistance, switch contact resistance and variation, thermoelectrical potential can both be ignored pressure measuring instrument impact.

Description

Be the pressure measuring instrument of power supply with dry cell

Technical field

The utility model relates to the instrument measured DC voltage.

Background technology

The current pressure measuring instrument 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 pressure measuring instrument 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.

Utility model content

The purpose of this utility model is a kind of pressure measuring instrument having five step discs of design, and 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.

The technical solution of the utility model is taked like this: pressure measuring instrument from 3V working power positive pole through 700 Ω resistance R _mand the adjustable resistance R to be made up of 22 26 Ω resistant series _p1, the adjustable resistance R to be made up of 22 1.2 Ω resistant series _p2, and the adjustable resistance R of range of adjustment between 0 ~ 1.3 Ω _p3, through five step discs, set up resistance R to 1018 Ω _n, then get back to 3V working power E negative pole composition pressure measuring instrument performance loop 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 pressure measuring instrument 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 pressure measuring instrument 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 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 0.1111 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 998.89 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 9998.89 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 910 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 are through 7.91 Ω resistance R ₅rear connection single-pole double-throw switch (SPDT) K ₁in × 1 range contact, then through 8190 Ω resistance R ₇connect single-pole double-throw switch (SPDT) K ₁in × 0.1 range contact, 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 _nbe connected with " 0 " contact of the temperature compensation dish W of 18 × 0.05 Ω resistance in seriess, set up resistance R at 1018 Ω _nhot end 10189 Ω resistance Rs in parallel with " 18 " two ends, contact of temperature compensation dish W ₈the negative pole of rear connection 3V working power, 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 pressure measuring instrument structure simple, volume-diminished, thus reduce production cost; When pressure measuring instrument five measurement dish resets, the internal wiring combined potential of pressure measuring instrument is A point current potential, some current potentials are " 0 ", so the zero potential of this pressure measuring instrument is very little, the thermoelectrical potential of 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

Accompanying drawing is a kind of schematic circuit of the present utility model.

Embodiment

In the accompanying drawings, the adjustable resistance R of 22 × 26 Ω _p1, represent adjustable resistance R _p1on have 22 resistances to be resistant series of 26 Ω, in like manner, the adjustable resistance R of 22 × 1.2 Ω _p2, represent adjustable resistance R _p2on have 22 resistances to be resistant series of 1.2 Ω, 20 × 1 Ω on first step disc measurement dish I represent that measurement dish I has 20 resistances to be resistant series of 1 Ω, 10 × 0.1111 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 0.1111 Ω, in the accompanying drawings, 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 1, in the accompanying drawings, 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.

Pressure measuring instrument standard operation current design becomes 1.1mA, and when × 1 range, be 902.09 Ωs through five step discs to Node B resistance from node C, connect 7.91 Ω resistance R ₅to single-pole double-throw switch (SPDT) K ₁in × 1 range contact time totally 910 Ω resistance values, from node C through resistance R ₆, resistance R ₇be 9100 Ω to resistance value during × 1 range contact, so 1mA working current flows through five step discs, 0.1mA working current flows through resistance R ₆, resistance R ₇; When × 0.1 range, be 902.09 Ωs through five step discs to Node B resistance from node C, connect 7.91 Ω resistance R ₅, 8190 Ω resistance R ₇after resistance be 9100 Ω, so 0.1mA working current flows through five step discs, 1mA working current flows through resistance R ₆.

When × 1 range, pressure measuring instrument 1mA working current is divided into four 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, then a road is through measurement dish V, and four road electric currents meet at Node B.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 flow through each branch current ratio between node A, Node B be: the 5th step disc: the 4th stepping: the 3rd step disc: the second step disc=1: 10: 100: 1000, when pressure measuring instrument 1mA electric current all flows through some resistance on measurement dish II, namely the brush on measurement dish II, measurement dish III, measurement dish IV, measurement dish V is all put after this resistance, and this resistance is at the measured " U of connection _x" two magnitudes of voltage measured between terminals are 0.1111mV, at measured " U _x" two two ends measuring terminal, the voltage added value of the every stepping of the second step disc is 1 × 10 ^-1mV, the voltage added value of the every stepping of the 3rd step disc is 1 × 10 ^-2mV, the voltage added value of the every stepping of the 4th step disc is 1 × 10 ^-3mV, the voltage added value of the every stepping of the 5th step disc is 1 × 10 ^-4mV.The each stepping of first step disc is 1mV.When × 0.1 range, the electric current flowing through five step discs is little of 1/10 when × 1 range, so when after working current standardization, each stepping of the first step disc is 1 × 10 ^-1mV, the voltage added value of the every stepping of the second step disc is 1 × 10 ^-2mV, the voltage added value of the every stepping of the 3rd step disc is 1 × 10 ^-3mV, the voltage added value of the every stepping of the 4th step disc is 1 × 10 ^-4mV, the voltage added value of the every stepping of the 5th step disc is 1 × 10 ^-5mV.

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 pressure measuring instrument temperature compensation dish of every stepping 50 μ V compensates temperature.

Pressure measuring instrument standard operation working current is 1.1mA, adopt two groups of dry cell series-feds, because dry cell often saves stable electrical kinetic potential between 1.35V ~ 1.65V, all pressure measuring instrument working current can be adjusted to standard state for realizing supply voltage at 1.35V ~ 1.65V, getting fixed resistance R _m=700 Ω, adjustable resistance RP ₁=22 × 26 Ω, adjustable resistance RP ₂=22 × 1.2 Ω, adjustable resistance R _p3be 0 ~ 1.3 Ω, being together in series with two groups of dry cells so just as pressure measuring instrument working power, also can work by external 3V 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, such dry cell can be adjusted to standardization pressure measuring instrument working current within the scope of normal electrical kinetic potential.

Claims (1)

1. be a pressure measuring instrument for power supply with dry cell, pressure measuring instrument from 3V working power positive pole through 700 Ω resistance R _mand the adjustable resistance R to be made up of 22 26 Ω resistant series _p1, the adjustable resistance R to be made up of 22 1.2 Ω resistant series _p2, and the adjustable resistance R of range of adjustment between 0 ~ 1.3 Ω _p3, through five step discs, set up resistance R to 1018 Ω _n, then get back to 3V working power E negative pole composition pressure measuring instrument performance loop 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 pressure measuring instrument 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 pressure measuring instrument 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 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 0.1111 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 998.89 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 9998.89 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 910 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 are through 7.91 Ω resistance R ₅rear connection single-pole double-throw switch (SPDT) K ₁in × 1 range contact, then through 8190 Ω resistance R ₇connect single-pole double-throw switch (SPDT) K ₁in × 0.1 range contact, 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 _nbe connected with " 0 " contact of the temperature compensation dish W of 18 × 0.05 Ω resistance in seriess, set up resistance R at 1018 Ω _nhot end 10189 Ω resistance Rs in parallel with " 18 " two ends, contact of temperature compensation dish W ₈the negative pole of rear connection 3V working power, 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.