CN101393235B

CN101393235B - DC potentiometer

Info

Publication number: CN101393235B
Application number: CN200810121910XA
Authority: CN
Inventors: 骆洪亮
Original assignee: Individual
Current assignee: Individual
Priority date: 2008-10-22
Filing date: 2008-10-22
Publication date: 2011-03-16
Anticipated expiration: 2028-10-22
Also published as: CN101393235A

Abstract

The present invention discloses a potential difference meter for the measurement of direct current voltage, which is provided with four step disks and one double wire sliding disk. The five disks respectively consist of a measuring disk and a replacing disk which has the same resistance value. The working current is divided into two branches with the proportion of 10 to 1 between two electric brushes of the first step disk. Two disks of each branch are connected in parallel with the current ratio of 10 to 1. Besides the first step disk, the electric brush of the measuring disk of each step disk and the electric brush of the replacing disk of each stepper disk are connected through a resistor or conducting wires. Each step disk or double wire sliding disk has no auxiliary disk, thus the volume of the device is reduced, and the manufacturing cost of the device is reduced; meanwhile, the five measuring disks are connected through conducting wires, and the influence of the variation and the thermoelectric potential is eliminated.

Description

DC potentiometer

Technical field

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

Background technology

Application number 2005100623569,2005100622373,2005100622585 etc. discloses the DC potentiometer that five step discs is arranged or two slide wire discs are arranged, each is made up of its second, third step disc measuring disk, replacement dish and bracket panel, 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, when second step disc puts at the 0th, second step disc equates with the 3rd step disc part resistance in parallel, when the 3rd step disc was put different indicating value, the circuit resistance was constant.When second step disc is declined when " 0 ", the 3rd step disc is put different indicating values, the circuit resistance is not having III " resistance changes during bracket panel; stepping of the every increase of the 3rd step disc, circuit resistance can increase half resistance of each stepping resistance, for the total resistance of holding circuit constant; at III " each stepping of bracket panel reduces same resistance, at this moment resistance minimum when second step disc puts at the 0th allows III " bracket panel resistance all seals in circuit, makes the circuit resistance constant.Because first step disc and two slide wire disc are formed by resistance identical measuring disk and replacement dish, so what indicating value no matter four dishes put, circuit always hinders constant.Second step disc is except that having measuring disk, replacement dish for this reason, having increased bracket panel distinguishes step disc and puts the 0th and the circuit of declining the 0 0th. two kind of situation and connect, the 3rd 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.Four, the 5th dish has also in like manner had bracket panel.

Because second, third, the 4th, the 5th step disc all has bracket panel, increased the number of plies of switch, thereby increased the volume of instrument, also make switch and apparatus structure become complicated, if particularly find second, third in the instrument verification process, the 4th, the 5th step disc measurement data is overproof, revise second, third, the internal layer resistance of the 4th, the 5th step disc switch bothers very much.

Summary of the invention

The objective of the invention is to design a kind of DC potentiometer that four step discs, two slide wire discs are arranged, in the connection of a measuring disk slip of four measurement disks, do not switch by switch, four step discs, two slide wire discs are all cancelled bracket panel, the volume that this can reduce instrument reduces production costs.

Technical scheme of the present invention is to take like this:

Electric current is set up resistance R N and range of adjustment adjustable resistance RP at 0～2 Ω through the resistor network on four step discs, the two slide wire disc to 926 Ω from the positive pole of DC potentiometer 4.5V working power ₃, again to 960 Ω fixed resistance R ₀, through the adjustable resistance R of 0～33 Ω _P2And the adjustable resistance R of 22 * 30 Ω _P1The negative pole of getting back to working power is formed the work loop of DC potentiometer; , arrive and set up resistance R N and lockable adjustable resistance R through being connected to galvanometer G double-point double-throw switch K between two normally closed contacts from standard cell EN positive pole _P3, arrive the standard loop that the standard cell negative pole is formed DC potentiometer again; Be used to connect " the U of measuring junction _X" two terminals, behind the resistor network of anodal terminal, again through the double-point double-throw switch K that is connected to galvanometer G between two normally closed contacts equalizing network to negative pole terminal composition DC potentiometer through four measurement disks, a measuring disk slip; It is characterized in that first step disc is made up of I measuring disk that 20 * 1000/11 Ω are respectively arranged and the I ' replacement dish, second step disc is made up of II measuring disk that 10 * 11 Ω are respectively arranged and the II ' replacement dish, and the brush of the brush of measuring disk and replacement dish is through 22 Ω resistance R on second step disc ₂Connect, the 3rd step disc is made up of III measuring disk that 10 * 11 Ω are respectively arranged and the III ' replacement dish, the brush of measuring disk is connected through lead with the brush of replacement dish on the 3rd step disc, the 4th step disc is made up of IV measuring disk that 10 * 1.1 Ω are respectively arranged and the IV ' replacement dish, and the brush of the brush of measuring disk and replacement dish is through 2.2 Ω resistance R on the 4th step disc ₄Connect, the 5th dish is two slide wire discs, two slide wire resistance Standard resistance ranges all are 0～11 Ω, be that top is 0 Ω, end is 11 Ω, wherein one is V measuring disk slip, another root is a V ' replacement dish slip, the index dial of two slide wire discs indicates 0,1,2 ... 10 big lattice of 100 one indicating value points, every big lattice are not marked numeral equally distributed 10 little lattice, the corresponding resistance of every big lattice is 1.1 Ω, " 0 " indicating value of two slide wire disc index dials, dish slip of the V ' replacement just and V measuring disk slip the 0th point, top on the i.e. brush of the two slide wire discs contact slide wire resistance, the index dial of two slide wire discs " 10 " indicating value, dish slip of the V ' replacement just and V measuring disk slip the 10th point, i.e. end on the brush of the two slide wire discs contact slide wire resistance; Brush on two slide wire resistances is with a slice sheet metal; The I ' replacement is coiled at the 20th and is connected the II ' replacement and coil the 10th point, and the II ' replacement is coiled at the 0th and connected the III ' replacement and coil the 10th point, and the 0th of III measuring disk connects II measuring disk the 10th point, and II measuring disk the 0th o'clock is through one 1903.2/11 Ω resistance R ₁The back is connected with the 0th of I measuring disk, and the I ' replacement coils at the 0th o'clock through one 213189/11 Ω resistance R ₃The back is coiled at the 0th with the IV ' replacement and is connected, and the IV ' replacement is coiled at the 10th and connected the V ' replacement dish slip the 0th point, the 10th connection of V measuring disk slip IV measuring disk the 0th point, and the 10th of IV measuring disk is connected with the 20th of I measuring disk; The I ' replacement dish brush connects DC potentiometer working power positive pole, and I measuring disk brush connects sets up resistance R N hot end; " the U that DC potentiometer is used to measure _X" two terminals, anodal terminal connects III measuring disk the 10th point, and the negative pole terminal is connected with the 0th of V measuring disk slip after through the double-point double-throw switch K that is connected to galvanometer G between two normally closed contacts.

By above technical scheme, four step discs and two slide wire discs are all without bracket panel, and this makes DC potentiometer simple in structure, and volume-diminished, whole instrument overall dimensions reduce many, have also reduced production cost; The measuring disk that instrument is used for measure portion connects with lead, contact resistance and variation be not in equalizing network, the just DC potentiometer work loop of influence always hinders, because total resistance resistance is very big, so variation can be ignored, the thermoelectric potential influence of several μ V be supply voltage, therefore influence can be ignored, zero potential can increase between slide wire disc and the I measuring disk lead resistance and revise.

Description of drawings

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

Embodiment

In Fig. 1, when two slide wire discs of four step discs and all during reset, left side resistance value equals 2121.2 Ω between two brushes of first step disc, the right resistance value equals 21212 Ω, therefore, between two brushes of first step disc flow in 10/11 left side of total current, flows in 1/11 the right.When each step disc was put other contact, the resistance that measuring disk increases in each step disc equaled the resistance that the replacement dish reduces, so what indicating value no matter four step discs, two slide wire discs put, left and right limit resistance value is constant between two brushes of first step disc.

DC potentiometer standard operation electric current is 1.1mA, left side electric current 1mA between two brushes of first step disc, the right electric current 0.1mA, left side electric current is divided into two branch roads that electric current equates after flowing to the contact that contacts with the II ' replacement dish brush, and one the tunnel through the II ' replacement dish brush, resistance 22 Ω resistance R ₂, to the contact that contact with II measuring disk brush, this roadlock value is 22 Ω, the contact that contacts with II measuring disk brush is arrived after through the 3rd step disc in another road, this roadlock value is 220 Ω, therefore, 22 Ω resistance R ₂On electric current be 10/11mA, the electric current on the 3rd step disc is 1/11mA.

The right electric current also is divided into two branch roads that electric current equates after flowing to the contact that contacts with the IV ' replacement dish brush, and one the tunnel through the IV ' replacement dish brush, resistance 2.2 Ω resistance R ₄, to the contact that contact with IV measuring disk brush, this roadlock value is 2.2 Ω, the contact that contacts with IV measuring disk brush is arrived after through two slide wire discs in the contact of another Lu Congdi IV ' replacement dish brush contact, this roadlock value is 22 Ω, therefore, 2.2 Ω resistance R ₄On electric current be 1/11mA, the electric current on two slide wire discs is 0.1/11mA.

After the working current standardization, the I measuring disk is thrown n ₁, the II measuring disk is thrown n ₂, the III measuring disk is thrown n ₃, the IV measuring disk is thrown n ₄, two slide wire discs are thrown n ₅(n is certain big lattice indicating value), K switch is thrown to the left side, is positioned at this moment that voltage is between two terminals of measurement:

U _X＝1/11×11n ₃+1/11×110+10/11×11n ₂+1×R ₁+1×1000n ₁/11-0.1×(20-n ₁)×1000/11-0.1×(10

-n ₄)×1.1-0.1/11×1.1n ₄-0.1/11×(10-n ₅)×1.1(mv)

＝n ₃+110/11+10n ₂+1×R ₁+1100n ₁/11-2000/11-1.1+0.11n ₄-0.01n ₄-0.1+0.01n ₅(mv)

＝n ₃+10n ₂+100n ₁+0.1n ₄+0.01n ₅+10+1903.2/11-2000/11-1.1-0.1(mv)

＝100n ₁+10n ₂+n ₃+0.1n ₄+0.01n ₅(mv)

Internal attachment standard is calibration like this: at " U _x" two of two ends measure terminals and connect 2V normal voltage signal by polarity, K switch is thrown to the left side, the measuring disk indicating value is identical with standard voltage value, by regulating working current adjusting resistance R _P1And R _P2, make the galvanometer nulling, again K switch to be thrown to the right, sampling is 926 Ω with the resistance of setting up resistance R N, 0～2 Ω adjustable resistance R has connected _P3, regulate adjustable resistance R _P3, make galvanometer nulling once more, again K switch is thrown to the left side, regulate adjustable resistance R _P2, make the galvanometer nulling, again K switch is thrown to the right, regulate adjustable resistance R _P3Make the galvanometer nulling, throw to the left side and throw when the equal nulling of galvanometer is not regulated on the right when K switch, the working current that DC potentiometer is described is with regard to standardization, promptly set up ohmically pressure drop and equate, at this moment with adjustable resistance R with the electromotive force of unsaturated standard cell EN _P3Locking, this DC potentiometer is from now on just as standard.

The DC potentiometer operating voltage is 1.5V, because the every joint stable electrical of dry cell kinetic potential is between 1.4V～1.65V, adopt three groups of dry cell series connection, all can adjust to standard state to the DC potentiometer working current at 4.2V～4.95V, get fixed resistance R for realizing supply voltage ₀=960 Ω, adjustable resistance R _P1=22 * 30 Ω, adjustable resistance R _P2Range of adjustment is between 0～33 Ω.

Galvanometer adopts the photoelectricity amplifying type, as AC12 type photoelectricity amplifying type galvanometer.

Claims

1. DC potentiometer, electric current is set up resistance R N and range of adjustment adjustable resistance RP at 0～2 Ω through the resistor network on four step discs, the two slide wire disc to 926 Ω from the positive pole of DC potentiometer 4.5V working power ₃, again to 960 Ω fixed resistance R ₀, through the adjustable resistance R of 0～33 Ω _P2And the adjustable resistance R of 22 * 30 Ω _P1The negative pole of getting back to working power is formed the work loop of DC potentiometer; , arrive and set up resistance R N and lockable adjustable resistance R through being connected to galvanometer G double-point double-throw switch K between two normally closed contacts from standard cell EN positive pole _P3, arrive the standard loop that the standard cell negative pole is formed DC potentiometer again; Be used to connect " the U of measuring junction _X" two terminals, behind the resistor network of anodal terminal, again through the double-point double-throw switch K that is connected to galvanometer G between two normally closed contacts equalizing network to negative pole terminal composition DC potentiometer through four measurement disks, a measuring disk slip; It is characterized in that first step disc is made up of I measuring disk that 20 * 1000/11 Ω are respectively arranged and the I ' replacement dish, second step disc is made up of II measuring disk that 10 * 11 Ω are respectively arranged and the II ' replacement dish, and the brush of the brush of measuring disk and replacement dish is through 22 Ω resistance R on second step disc ₂Connect, the 3rd step disc is made up of III measuring disk that 10 * 11 Ω are respectively arranged and the III ' replacement dish, the brush of measuring disk is connected through lead with the brush of replacement dish on the 3rd step disc, the 4th step disc is made up of IV measuring disk that 10 * 1.1 Ω are respectively arranged and the IV ' replacement dish, and the brush of the brush of measuring disk and replacement dish is through 2.2 Ω resistance R on the 4th step disc ₄Connect, the 5th dish is two slide wire discs, two slide wire resistance Standard resistance ranges all are 0～11 Ω, be that top is 0 Ω, end is 11 Ω, wherein one is V measuring disk slip, another root is a V ' replacement dish slip, the index dial of two slide wire discs indicates 0,1,2 ... 10 big lattice of 100 one indicating value points, every big lattice are not marked numeral equally distributed 10 little lattice, the corresponding resistance of every big lattice is 1.1 Ω, " 0 " indicating value of two slide wire disc index dials, dish slip of the V ' replacement just and V measuring disk slip the 0th point, top on the i.e. brush of the two slide wire discs contact slide wire resistance, the index dial of two slide wire discs " 10 " indicating value, dish slip of the V ' replacement just and V measuring disk slip the 10th point, i.e. end on the brush of the two slide wire discs contact slide wire resistance; Brush on two slide wire resistances is with a slice sheet metal; The I ' replacement is coiled at the 20th and is connected the II ' replacement and coil the 10th point, and the II ' replacement is coiled at the 0th and connected the III ' replacement and coil the 10th point, and the 0th of III measuring disk connects II measuring disk the 10th point, and II measuring disk the 0th o'clock is through one 1903.2/11 Ω resistance R ₁The back is connected with the 0th of I measuring disk, and the I ' replacement coils at the 0th o'clock through one 213189/11 Ω resistance R ₃The back is coiled at the 0th with the IV ' replacement and is connected, and the IV ' replacement is coiled at the 10th and connected the V ' replacement dish slip the 0th point, the 10th connection of V measuring disk slip IV measuring disk the 0th point, and the 10th of IV measuring disk is connected with the 20th of I measuring disk; The I ' replacement dish brush connects DC potentiometer working power positive pole, and I measuring disk brush connects sets up resistance R N hot end; Connect measured " U _X" two terminals, anodal terminal connects III measuring disk the 10th point, and the negative pole terminal is connected with the 0th of V measuring disk slip after through the double-point double-throw switch K that is connected to galvanometer G between two normally closed contacts.