CN201035080Y

CN201035080Y - Novel voltage measurement device

Info

Publication number: CN201035080Y
Application number: CNU2007201098002U
Authority: CN
Inventors: 张春雷; 方李
Original assignee: Individual
Current assignee: Individual
Priority date: 2007-05-29
Filing date: 2007-05-29
Publication date: 2008-03-12
Anticipated expiration: 2017-05-29

Abstract

The utility model provides a new type voltage measuring device for DC voltage. A first stepping disk of the voltage measuring device consists of a measuring disk of 21*10 Omega, a non-resistance auxiliary disk Iota' and a non-resistance auxiliary disk Iota''; a second stepping disk consists of a measuring disk composed of an annular resistance of 9*9 Omega and two resistance networks of 1 Omega, and an auxiliary disk composed of a resistance of 10*0.5 Omega; a third disk is a double slide-wire disk. The two measuring disks are connected with the measuring slide wires through wires, switching is not needed when measuring, which can prevent variation and thermoelectric force influence when the voltage measuring device measures. Further, two ranges are converted by two resistances of 200 Omega and 180 Omega, and substitution disks of the first and the second stepping disks are omitted.

Description

The novel voltage measurement mechanism

Technical field

The utility model relates to the instrument that DC voltage is measured.

Background technology

Current for the potential difference meter that three measuring disk are arranged, in the connection between three measuring disk, telophragma generally adopts switch to switch, and so just produces the variation of contact resistance, brings restriction to resolution.In order to overcome this problem, generally adopt big brush with the increase contact area, and adopt silver-carbon/carbon-copper composite material; Patent No. ZL200520101772.0 has announced that the potential difference meter that three measuring disk are arranged solves the variation new method of switch contact resistance, its first, second step disc respectively has measuring disk, replacement dish and bracket panel are formed, measuring disk is identical with resistance on the replacement dish, resistance of the every increase of measuring disk, the replacement dish just reduces same resistance, because first step disc was declined at 0 o'clock, the total resistance of circuit changed when second step disc was put different indicating value, first step disc was put at 0 o'clock, the total resistance of circuit was constant when second step disc was put different indicating value, first step disc removes for this reason measuring disk, outside the replacement dish, increased bracket panel distinguish step disc put 0 and the circuit of declining 0 two kinds of situations connect, second step disc has also increased bracket panel, has 10 resistance to insert or cut out several resistance respectively above and makes the total resistance of circuit constant.Two measuring disk connect the back and are connected two with slide wire disc and measure between terminals, brush on the step disc switch is got rid of measured outside the loop, do not exist switch to switch between the resistance on three measuring disk, also just do not produce variation; Because first, second step disc all has the replacement dish, has increased the number of plies of first, second step disc switch, thereby has increased the volume of instrument, also make switch and apparatus structure become complicated.

The utility model content

The purpose of this utility model is a kind of novel voltage measurement mechanism of design, telophragma does not switch by switch in the connection of three measuring disk, and first, second step disc cancellation replacement dish, and adopt diverter branch to carry out two ranges switchings, make resolution reach 1 μ V.

The technical solution of the utility model is taked like this: from the positive pole of voltage measuring apparatus 1.5V working power through the resistance measurement network formed by two step discs, two slide wire disc, range transfer resistance and a range selector setting resistance R to 463 Ω _NAnd the lockable adjustable resistance R of 0～1 Ω _P2, again through 0～105 Ω adjustable resistance R _P1Form voltage measuring apparatus work loop to the negative pole of working power; Standard cell E _NAnodal through being connected to the double-point double-throw switch K of galvanometer G between two normally closed contacts ₂To setting up resistance R _NAnd lockable adjustable resistance R _P2, process 100K Ω current-limiting resistance R is to standard cell E again _NNegative pole is formed the voltage measuring apparatus standard loop; Connect measured " U _X" two terminals, anodal terminal through two measuring disk and two slide wire disc after, again through being connected to the double-point double-throw switch K of galvanometer G between two normally closed contacts ₂Form the voltage measuring apparatus equalizing network to the negative pole terminal; First step disc has measuring disk I, it has 0,1,2 ... 22 totally 23 gears, except that between 0,1 contact, directly connecting, connect one of 10 Ω resistance between all the other each grade contacts, other has bracket panel I ' and bracket panel I "; the brush of bracket panel I ' and bracket panel I " the tie point that is connected with lead of brush be circuit node B, bracket panel I ' and bracket panel I " 0 contact isolated, all the other contacts connect with lead; The 3rd dish is two slide wire discs, two slip thickness materials are identical, resistance all is 0.5 Ω, wherein one is measurement slip III, another root is auxiliary slip III ', and the index dial of two slide wire discs divides 10 big lattice, and the resistance of every big lattice correspondence is 0.05 Ω, every big lattice divide 10 little lattice, and the brush on two slide wire resistances is with a slice metallic brush sheet; Second step disc is made up of measuring disk II and bracket panel II ', measuring disk II has 0,1,2 ... 10 totally 11 gears have the resistance of 99 Ω to connect into ring-type: the 1st resistance R above 0～8 gear ₁One end welds the 2nd resistance R ₂One end, resistance R ₂The other end welds the 3rd resistance R ₃One end ... welding successively, the 8th resistance R ₈The other end and the 9th resistance R ₉An end tie point be circuit node H, the 9th resistance R ₉The other end and the 1st resistance R ₁The other end and the 3rd dish measure 0 of slip III being connected, 0 that measures slip III is circuit node D, resistance R ₁With resistance R ₂Tie point be connected resistance R through 12 Ω resistance with the 1st contact ₂With resistance R ₃Tie point be connected resistance R through 6 Ω resistance with the 2nd contact ₃With resistance R ₄Tie point be connected resistance R through 2 Ω resistance with the 3rd contact ₄With resistance R ₅Tie point be connected resistance R with the 4th contact ₅With resistance R ₆Tie point be connected resistance R with the 5th contact ₆With resistance R ₇Tie point be connected resistance R through 2 Ω resistance with the 6th contact ₇With resistance R ₈Tie point be connected resistance R through 6 Ω resistance with the 7th contact ₈With resistance R ₈Tie point be that node H one tunnel is connected with the 8th contact through 12 Ω resistance, another road is connected with the 9th contact through 11 Ω resistance to node F after through 1 Ω resistance again, node F through 1 Ω resistance to node C, node C is connected with the 10th contact through 10 Ω resistance, " 0 " contact of measuring disk II is connected with node D through 20 Ω resistance, is the resistance of 10 * 0.5 Ω on the bracket panel II ' of second step disc; Bracket panel II ' the 10th contact and 200 Ω resistance R ₁₄An end be connected in node A, node A connects the positive pole of voltage measuring apparatus working power, 0 contact of bracket panel II ' connects bracket panel I " 0 contact, the brush of bracket panel II ' connects bracket panel I " other contact except that 0 contact, the brush of measuring disk II is through 200 Ω resistance R ₁₂Back connected node B, bracket panel I ' other contact except that 0 contact connects measuring disk I the 22nd contact, measuring disk I the 0th, 1 contact is connected with node C, and 0 contact of bracket panel I ' is connected with node D after through 220 Ω resistance, measures slip III the 10th o'clock through 84.5 Ω resistance R ₁₃With 1800 Ω resistance R ₁₅An end be connected in range switch K ₁* 1 range contact, resistance R ₁₅The other end and 200 Ω resistance R ₁₄The other end and range switch K ₁* 0.1 range contact connects range switch K ₁Normally closed contact connect to set up resistance R _NNoble potential one end; Two of voltage measuring apparatus are measured terminal, and positive pole is connected with measuring disk I brush, and negative pole is through double-point double-throw switch K ₂The back is connected with auxiliary slip III '.

By above technical scheme, first step disc need not the replacement dish, does not all have resistance on the two-layer bracket panel, can be contained in the switch nexine, and measuring disk I is contained in the switch skin; Second step disc need not the replacement dish, 15 ° of angles are rotated in each stepping of switch, every layer of 24 contact that distributes, deduct two grades of location, each 11 contact of the bracket panel II ' of second step disc and measuring disk II just in time are distributed in same one deck of switch, respectively account for half cycle, and resistance is contained in the switch skin, unload when resistance is overproof and load onto easily, this brings convenience for debugging and maintenance; This just makes voltage measuring apparatus simple in structure, and volume-diminished has also reduced production cost; On the total circuit partly in voltage measuring apparatus internal measurement loop and work loop, there is not switch, so there is not variation influence, when three measuring disk resets of voltage measuring apparatus, the voltage measuring apparatus working current converges at the D point, the zero potential of voltage measuring apparatus is exactly a D point zero potential, in measuring the loop, do not exist working current to flow through lead resistance, so this voltage measuring apparatus zero potential is very little; Two slide wire resistance thickness materials are identical, and the thermoelectrical potential equal and opposite in direction of generation, direction are opposite, so this voltage measuring apparatus thermoelectrical potential is also very little, therefore, also can obtain fine repeatability when * 0.1 this voltage measuring apparatus of range is measured.

Description of drawings

Accompanying drawing is the utility model schematic circuit.

Embodiment

Among the figure, measuring disk II has 9 the 9 end to end resistance rings of Ω between 1～8 contact, when measuring disk II puts " 4 ", " 5 ", the brush of measuring disk II is to being that 59 Ω resistance are in parallel with 49 Ω resistance between the node D, back in parallel resistance is 20 Ω to the maximum, other contact of measuring disk II all will be connected to 20 Ω to the resistance between the node D, and corresponding point directly are connected on " 4 ", " 5 " contact and the resistance ring; When measuring disk II put " 3 " or puts " 6 ", the brush of measuring disk II was to being that 39 Ω resistance are in parallel with 69 Ω resistance between the node D, and back in parallel resistance is 18 Ω, so 3,6 contacts are connected with corresponding point on the resistance ring through 2 Ω resistance; When measuring disk II put " 2 " or puts " 7 ", the brush of measuring disk II was to being that 29 Ω resistance are in parallel with 79 Ω resistance between the node D, and back in parallel resistance is 14 Ω, so 2,7 contacts are connected with corresponding point on the resistance ring through 6 Ω resistance; When measuring disk II set or when putting " 8 ", the brush of measuring disk II is to being that 19 Ω resistance is in parallel with 89 Ω resistance between the node D, and back in parallel resistance is 8 Ω, so 1,8 contacts are connected with corresponding point on the resistance ring through 12 Ω resistance; When measuring disk II puts " 9 ", the brush of measuring disk II is to being that 11 Ω resistance add 1 Ω resistance and add that 8 Ω connect into 20 Ω resistance when measuring disk II puts " 10 " on the resistance ring again between the node D, and the brush of measuring disk II is to being that 10 Ω resistance add 2 Ω resistance and add that 8 Ω connect into 20 Ω resistance on the resistance ring again between the node D.When measuring disk II reset, the brush of measuring disk II is to being that 20 Ω resistance connect between the node D,

The first step disc reset, second step disc are put " n " (n=0,1,2,3 ... 9,10) time, the brush of bracket panel I ' is that two resistance that are both 220 Ω are in parallel with resistance value between the node D, is 110 Ω therefore.

First step disc is put " n " (n=0,1,2,3 ... 22), during the second step disc reset, the brush of bracket panel I ' is that two resistance that are both 220 Ω are in parallel with resistance value between the node D, is 110 Ω therefore.

When first, second step disc during not reset, the calculating of the resistance value between the brush of bracket panel I ' and the node D removes second step disc and puts outside " 8,9,10 ", all needs to carry out triangle-star conversion.

During the second step disc set, the calculating of resistance value between the brush of bracket panel I ' and the node D: establish resistance (R ₂+ R ₃+ ... + R ₈) and resistance R ₉The both sides resistance is equivalent to resistance r ₁, resistance R ₉With resistance R ₁The both sides resistance is equivalent to resistance r ₁' resistance (R ₂+ R ₃+ ... + R ₈) and resistance R ₁The both sides resistance is equivalent to resistance r ₁", be equivalent to resistance r ₁, r ₁', r ₁" intersection point is Q ₁:

R then ₁=(R ₂+ R ₃+ ... + R ₈) * R ₉/ (R ₁+ R ₂+ ... + R ₉)=7 * 9 * 9/9 * 9 Ω=7 Ω

r ₁’＝R ₁×R ₉/(R ₁+R ₂+…+R ₉)＝9×9/9×9Ω＝1Ω

r ₁”＝(R ₂+R ₃+…+R ₉)×R ₁/(R ₁+R ₂+…+R ₉)＝7×9×9/9×9Ω＝7Ω

Resistance value equals (212 Ω+r between the brush of bracket panel I ' and the node D ₁) * (212 Ω+r ₁")/(2 * 219) Ω+r ₁'=219 Ω/2+1 Ω=109.5 Ω+1 Ω=110.5 Ω

When second step disc is put " 2 ", the calculating of resistance value between the brush of bracket panel I ' and the node D: establish resistance (R ₃+ R ₄+ ... + R ₈) and resistance R ₉The both sides resistance is equivalent to resistance r ₂, resistance R ₉With resistance (R ₁+ R ₂) the both sides resistance is equivalent to resistance r ₂' resistance (R ₃+ R ₄+ ... + R ₈) and resistance (R ₁+ R ₂) the both sides resistance is equivalent to resistance r ₂", be equivalent to resistance r ₂, r ₂', r ₂" intersection point is Q ₂:

R then ₂=6 Ω r ₂'=2 Ω r ₂Resistance value equals (212 Ω+r between the brush of "=12 Ω bracket panel II ' and the node D ₂) * (200 Ω+6 Ω+r ₂")/(2 * 218) Ω+r ₂'=218 Ω/2+2 Ω=109 Ω+2 Ω=111 Ω.

In like manner, when second step disc was put " 3 ", resistance value was 111.5 Ω between the brush of bracket panel I ' and the node D,

When second step disc was put " 4 ", resistance value was 112 Ω between the brush of bracket panel I ' and the node D,

When second step disc is put " 5 ", resistance value is 112.5 Ω between the brush of bracket panel I ' and the node D, when second step disc is put " 9 ", resistance value is (211/2+9) Ω=114.5 Ω between the brush of bracket panel I ' and the node D, when second step disc was put " 10 ", resistance value was (210/2+10) Ω=115 Ω between the brush of bracket panel I ' and the node D.Because the every stepping of measuring disk II increases by 0.5 Ω, so the every stepping of bracket panel II ' reduces by 0.5 Ω, makes the total resistance of circuit constant.

When the first or second step disc reset, the resistance value between the brush of bracket panel I ' and the node D is 110 Ω, and 10 * 0.5 Ω resistance of bracket panel II ' all enter circuit, and making the resistance value between node A and the node D is that 115 Ω remain unchanged.

Electric current during the standardization of voltage measuring apparatus working current is 2.2mA, when * 1 range, through node D, adds the resistance R of slide wire resistance and 84.5 Ω from node A ₁₃To K switch ₁* 200 Ω resistance values between 1 range contact and the resistance R of 2000 Ω ₁₄, resistance R ₁₅The sum parallel connection, the electric current that therefore flows through bracket panel II ' is 2mA, flows through resistance R ₁₇, resistance R ₁₈Electric current be 0.2mA.

When * 1 range, the 2mA electric current flows through the 10th the process node D of bracket panel II ' to measuring slip III the 10th point, and measuring disk II puts " n " [n=1,2,3 ... 8 (r ₈=0) in the time of], I is to being equivalent to resistance r for Node B process measuring disk _n, r _n', r _n" intersection point Q _n(n=1,2,3 ... 8) with through 200 Ω resistance R ₁₂To intersection point Q _nResistance value equates that when measuring disk II put " 9 ", I was to the resistance value of node F and through 200 Ω resistance R for Node B process measuring disk ₁₂Resistance value to node F all equals 211 Ω, so flow through measuring disk I and 200 Ω resistance R ₁₂Electric current respectively be 1mA, when measuring disk II puts " 10 ", Node B through measuring disk I to the resistance value of node C and through 200 Ω resistance R ₁₂Resistance value to node C all equals 210 Ω, so flow through measuring disk I and 200 Ω resistance R ₁₂Electric current also respectively be 1mA.

For 9 the 9 Ω end to end resistance rings of measuring disk II between 1～8 contact, resistance R during measuring disk II set ₁To be all 9 Ω resistance in parallel with 8 resistances, flows through resistance R ₉Electric current be 1/9mA, the voltage U between node H and the node D _HD=1/9 * 9mV=1mV; Resistance (R when measuring disk II puts " 2 " ₁+ R ₂) to be all 9 Ω resistance in parallel with 7 resistances, flows through resistance R ₉Electric current be 2/9mA, the voltage U between node H and the node D _HD=2/9 * 9mV=2mV; (n=1,2,3 when in like manner, measuring disk II puts " n " ... 8) voltage U between resistance nodes H and the node D _HD=nmV; When measuring disk II puts " 9 ", the voltage U between node F and the node D on the 8 Ω resistance rings _HD=8mV adds 1 Ω resistance R ₁₀Last 1mV, 9mV altogether; When measuring disk II puts " 10 ", the voltage U between node C and the node D on the 8 Ω resistance rings _HD=8mV adds 1 Ω resistance R ₁₀Last 1mV and 1 Ω resistance R ₁₁Last 1mV, 10mV altogether; When measuring disk I and measuring disk II reset, electric current is without resistance R ₉, U _CD=0mV; The electric current that flows through measuring disk I when not reset of measuring disk I is superimposed upon on the measuring disk II at the 10mV voltage between node C, the D, resistance between 0,1 contact of replacement measuring disk I, during the working current standardization, the every stepping of first step disc is 10mV, the every stepping of second step disc is 1mV, and the electric current on the 3rd dish is 2mA, and every big lattice resistance is 0.05 Ω, voltage on every big lattice is 2 * 0.05 Ω=0.1mV, and therefore every little lattice are 10 μ V; Measure terminals and connect measured when two of voltage measuring apparatus, when rotation voltage measuring apparatus measuring disk makes the galvanometer nulling, voltage measuring apparatus equates with measured voltage that at two voltages of measuring between terminal at this moment the indicating value on the voltage measuring apparatus measuring disk is measured magnitude of voltage.This voltage measuring apparatus highest measurement voltage is 230mV, and minimum resolution is 10 μ V.

When * 0.1 range, pass through node D to K switch from node A ₁* 200 Ω resistance and 1800 Ω resistance R between 1 range contact ₁₅Be connected into 2000 Ω heels, 200 Ω resistance R ₁₄Parallel connection, the electric current that therefore flows through bracket panel II ' is 0.2mA, flows through resistance R ₁₈Electric current be 2mA

When first step disc is put n ₁, second step disc puts n ₂, the 3rd dish puts n ₃(n ₃Represent big lattice indicating value) " U at this moment _x" two measure that voltage is between terminal:

U _x=1n ₁+ 0.1n ₂+ 0.01n ₃(mV) at this moment every little lattice are 1 μ V.

The electromotive force of every series-produced standard cell disperses, and between 1.0188V～1.0196V, standardized working current is 2.2mA, therefore sets up resistance R _NGet 463 Ω, add the lockable adjustable resistance R of 0～1 Ω _P2, variation range that can the coverage criteria cell emf.

Electromotive force was about 1.65V when dry cell was new, and to 1.35V when following, the electric current shakiness can both make the working current of voltage measuring apparatus be adjusted to standardization in order to make dry cell under new, former affection condition, gets adjustable resistance R with old _P1Be 0～105 Ω; Dry cell electromotive force usable range is between 1.42～1.65V.

Normalized current is to determine like this: 200mV standard signal voltage is pressed polarity and voltage measuring apparatus " U _x" two measure terminal and connect, voltage measuring apparatus step disc indicating value is identical with the standard signal magnitude of voltage, double-point double-throw switch K ₂Throw to the left side, regulate adjustable resistance R _P1, make galvanometer G nulling; Again with double-point double-throw switch K ₂Throw to the right, regulate adjustable resistance R _P2, make galvanometer G nulling, at this moment adjustable resistance R _P2Locking; When using from now on, voltage measuring apparatus is standard according to this.

Claims

1. novel voltage measurement mechanism, from the positive pole of voltage measuring apparatus 1.5V working power through the resistance measurement network formed by two step discs, two slide wire disc, range transfer resistance and a range selector setting resistance R to 463 Ω _NAnd the lockable adjustable resistance R of 0～1 Ω _P2, again through 0～105 Ω adjustable resistance R _P1Form voltage measuring apparatus work loop to the negative pole of working power; Standard cell E _NAnodal through being connected to the double-point double-throw switch K of galvanometer G between two normally closed contacts ₂To setting up resistance R _NAnd lockable adjustable resistance R _P2, process 100K Ω current-limiting resistance R is to standard cell E again _NNegative pole is formed the voltage measuring apparatus standard loop; Connect measured " U _X" two terminals, anodal terminal through two measuring disk and two slide wire disc after, again through being connected to the double-point double-throw switch K of galvanometer G between two normally closed contacts ₂Form the voltage measuring apparatus equalizing network to the negative pole terminal; It is characterized in that first step disc has measuring disk I, it has 0,1,2 ... 22 totally 23 gears, except that between 0,1 contact, directly connecting, connect one of 10 Ω resistance between all the other each grade contacts, other has bracket panel I ' and bracket panel I "; the brush of bracket panel I ' and bracket panel I " the tie point that is connected with lead of brush be circuit node B, bracket panel I ' and bracket panel I " 0 contact isolated, all the other contacts connect with lead; The 3rd dish is two slide wire discs, two slip thickness materials are identical, resistance all is 0.5 Ω, wherein one is measurement slip III, another root is auxiliary slip III ', and the index dial of two slide wire discs divides 10 big lattice, and the resistance of every big lattice correspondence is 0.05 Ω, every big lattice divide 10 little lattice, and the brush on two slide wire resistances is with a slice metallic brush sheet; Second step disc is made up of measuring disk II and bracket panel II ', measuring disk II has 0,1,2 ... 10 totally 11 gears have the resistance of 99 Ω to connect into ring-type: the 1st resistance R above 0～8 gear ₁One end welds the 2nd resistance R ₂One end, resistance R ₂The other end welds the 3rd resistance R ₃One end ... welding successively, the 8th resistance R ₈The other end and the 9th resistance R ₉An end tie point be circuit node H, the 9th resistance R ₉The other end and the 1st resistance R ₁The other end and the 3rd dish measure 0 of slip III being connected, 0 that measures slip III is circuit node D, resistance R ₁With resistance R ₂Tie point be connected resistance R through 12 Ω resistance with the 1st contact ₂With resistance R ₃Tie point be connected resistance R through 6 Ω resistance with the 2nd contact ₃With resistance R ₄Tie point be connected resistance R through 2 Ω resistance with the 3rd contact ₄With resistance R ₆Tie point be connected resistance R with the 4th contact ₅With resistance R ₆Tie point be connected resistance R with the 5th contact ₆With resistance R ₇Tie point be connected resistance R through 2 Ω resistance with the 6th contact ₇With resistance R ₈Tie point be connected resistance R through 6 Ω resistance with the 7th contact ₈With resistance R ₉Tie point be that node H one tunnel is connected with the 8th contact through 12 Ω resistance, another road is connected with the 9th contact through 11 Ω resistance to node F after through 1 Ω resistance again, node F through 1 Ω resistance to node C, node C is connected with the 10th contact through 10 Ω resistance, " 0 " contact of measuring disk II is connected with node D through 20 Ω resistance, is the resistance of 10 * 0.5 Ω on the bracket panel II ' of second step disc; Bracket panel II ' the 10th contact and 200 Ω resistance R ₁₄An end be connected in node A, node A connects the positive pole of voltage measuring apparatus working power, 0 contact of bracket panel II ' connects bracket panel I " 0 contact, the brush of bracket panel II ' connects bracket panel I " other contact except that 0 contact, the brush of measuring disk II is through 200 Ω resistance R ₁₂Back connected node B, bracket panel I ' other contact except that 0 contact connects measuring disk I the 22nd contact, measuring disk I the 0th, 1 contact is connected with node C, and 0 contact of bracket panel I ' is connected with node D after through 220 Ω resistance, measures slip III the 10th o'clock through 84.5 Ω resistance R ₁₃With 1800 Ω resistance R ₁₅An end be connected in range switch K ₁* 1 range contact, resistance R ₁₅The other end and 200 Ω resistance R ₁₄The other end and range switch K ₁* 0.1 range contact connects range switch K ₁Normally closed contact connect to set up resistance R _NNoble potential one end; Two of voltage measuring apparatus are measured terminal, and positive pole is connected with measuring disk I brush, and negative pole is through double-point double-throw switch K ₂The back is connected with auxiliary slip III '.