CN101788586B

CN101788586B - DC potentiometer

Info

Publication number: CN101788586B
Application number: CN2009102590799A
Authority: CN
Inventors: 骆晓英
Original assignee: Individual
Current assignee: Individual
Priority date: 2008-08-28
Filing date: 2008-08-28
Publication date: 2011-08-24
Anticipated expiration: 2028-08-28
Also published as: CN101788586A

Abstract

The invention discloses a DC potentiometer used for DC voltage measurement, comprising three stepping panels and a double-slide-wire panel, wherein for each panel, a measuring panel and replacing panes are formed by electric resistances with the same resistance value. The three measuring panels and a measuring-panel slide wire are directly connected by leads. Without the switchover of a switch, no affection of variation and of thermoelectric potential exists during the measurement of the DC potentiometer.

Description

A kind of DC potentiometer that adopts slide wire disc

Technical field

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

Background technology

Application number 200510062356.9 grades have been announced three step discs, the DC potentiometer of two slide wire discs, 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, and when second step disc put at the 0th, second step disc equated 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 measurement disks is connected two and measures between terminal, and the brush on the step disc switch is got rid of outside the measurement loop, does not exist switch to switch between the resistance on the four measurement disks, does not also just produce variation; The thermoelectrical potential that has also solved switch with contact variable thermoelectric potential influence.

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

Summary of the invention

The objective of the invention is to design a kind of DC potentiometer that three step discs and two slide wire discs are arranged, contact resistance and variation that its measuring switch stepping is switched, the switch thermoelectrical potential does not influence measurement result; And three step discs and two slide wire discs are all cancelled bracket panel.

The technical solution used in the present invention is: it comprises that electric current sets up resistance R N and range of adjustment adjustable resistance RP at 0～2 Ω through the resistor network on three step discs, the two slide wire disc to 926 Ω from the positive pole of DC potentiometer 4.5V working power ₃, again to 970 Ω fixed resistance R ₀, through the adjustable resistance R of 0～35 Ω _P2And the adjustable resistance R of 22 30 Ω resistance compositions _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, form the equalizing network of DC potentiometer again to the negative pole terminal through the double-point double-throw switch K that is connected to galvanometer G between two normally closed contacts through three measuring disk, a measuring disk slip; It is characterized in that first step disc is that I measuring disk and the I ' replacement dish that 1000/11sts Ω resistance are formed formed by 20 resistances are respectively arranged, second step disc is made up of each II measuring disk and the II ' replacement dish of being made up of 10 10 Ω resistance, the brush of measuring disk is connected through lead with the brush of replacement dish on second step disc, the 3rd step disc is made up of each III measuring disk and the III ' replacement dish of being made up of 10 11 Ω resistance, and the brush of the brush of measuring disk and replacement dish is through 22 Ω resistance R on the 3rd step disc ₂Connect, the 4th dish is two slide wire discs, two slide wire resistance Standard resistance ranges of this pair slide wire disc all are 0～110 Ω, be that top is 0 Ω, end is 110 Ω, wherein one is IV measuring disk slip, another root is an IV ' 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 11 Ω, " 0 " indicating value of two slide wire disc index dials, dish slip of the IV ' replacement just and IV measuring disk slip the 0th contact, 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 IV ' replacement just and IV measuring disk slip the 10th contact, 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 dish brush connects DC potentiometer working power positive pole, and the I ' replacement is coiled the 20th contact and connected the II ' replacement and coil the 10th contact, and II measuring disk the 0th contact is 2132/11sts Ω resistance R through a resistance ₁The back is connected with I measuring disk the 0th contact, and it is 210890/11sts Ω resistance R through a resistance that the 0th contact is coiled in the I ' replacement ₃The back is coiled the 0th contact with the III ' replacement and is connected, the III ' replacement is coiled the 10th contact and is connected the IV ' replacement dish slip the 0th contact, IV measuring disk slip the 10th contact connects III measuring disk the 0th contact, and III measuring disk the 10th contact is connected with I measuring disk the 20th contact; I measuring disk brush connects sets up resistance R N hot end; Connect measured " U _X" two terminals, anodal terminal connects II measuring disk the 10th contact, the negative pole terminal is connected with IV measuring disk slip the 0th contact after through the double-point double-throw switch K that is connected to galvanometer G between two normally closed contacts.

By above technical scheme, three 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 I measuring disk and the right measuring disk lead resistance greatly to be revised, and the zero potential I increases between I measuring disk and the left side measuring disk lead resistance and revises.

Description of drawings

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

In Fig. 1,22 * 30 Ω adjustable resistances resistance R _P1, expression adjustable resistance resistance R _P1Hindered by 22 30 Ω resistance, in like manner, it is that 1000/11sts Ω resistance are formed that 20 * 1000/11 Ω represent by 20 resistances, and 10 * 11 Ω represent to be made up of 10 11 Ω resistance.

Embodiment

Embodiment 1, in Fig. 1, when two slide wire discs of three step discs and all during reset, left side resistance equals 2112 Ω between two brushes of first step disc, the right resistance equals 21120 Ω, all-in resistance is 1920 Ω between two brushes of first step disc, and therefore 10/11 on the left side of total current flows between two brushes of first step disc, and 1/11 flows on the right.When the two slide wire discs of three step discs and were put other indicating value, the resistance that measuring disk increases equaled the resistance that the replacement dish reduces, so what indicating value no matter three step discs, two slide wire discs put, circuit always hinders constant.

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, the right electric current is divided into two branch roads after flowing to the contact that contacts with the III ' replacement dish brush, and one the tunnel through the III ' replacement dish brush, resistance 22 Ω resistance R ₂, to the contact that contact with III measuring disk brush, this roadlock value is 22 Ω, the contact that contacts with III measuring disk brush is arrived after through two slide wire discs in another road, this roadlock value is 220 Ω, therefore, 22 Ω resistance R ₂On 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, two slide wire discs are thrown n ₄(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＝1×10n ₂+1×R ₁+1×1000n ₁/11-0.1×(20-n ₁)×1000/11

-0.1×(10-n ₃)×11-0.1/11×11n ₃-0.1/11×(10-n ₄)×11

＝10n ₂+2132/11+1000n ₁/11-2000/11+100n ₁/11-11+1.1n ₃-0.1n ₃-1+0.1n ₄

＝100n ₁+10n ₂+n ₃+0.1n ₄+(2000+121+11)/11-2000/11-11-1

＝100n ₁+10n ₂+n ₃+0.1n ₄(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, the electromotive force of unsaturated standard cell disperses when dispatching from the factory in factory, and between 1.0188～1.0196V, sampling is 926 Ω with the resistance of setting up resistance R N, and 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 _P1, adjustable resistance R _P2, make the galvanometer nulling, again K switch is thrown to the right, regulate adjustable resistance R _P3, make the galvanometer nulling, when K switch is thrown to the left side and thrown to the right and do not regulate, during the equal nulling of galvanometer, the working current standardization of DC potentiometer is described, promptly sets 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 between 1.4V～1.65V, all can be adjusted to standard state to the DC potentiometer working current for realizing supply voltage at 4.2V～4.95V, gets fixed resistance R ₀=970 Ω, adjustable resistance R _P1=22 * 30 Ω, adjustable resistance R _P2Range of adjustment is between 0～35 Ω.

Claims

1. DC potentiometer that adopts slide wire disc, electric current is set up resistance R N and range of adjustment adjustable resistance RP at 0～2 Ω through the resistor network on three step discs, the two slide wire disc to 926 Ω from the positive pole of DC potentiometer 4.5V working power ₃, again to 970 Ω fixed resistance R ₀, through the adjustable resistance R of 0～35 Ω _P2And the adjustable resistance R of 22 30 Ω resistance compositions _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, form the equalizing network of DC potentiometer again to the negative pole terminal through the double-point double-throw switch K that is connected to galvanometer G between two normally closed contacts through three measuring disk, a measuring disk slip; It is characterized in that first step disc is that I measuring disk and the I ' replacement dish that 1000/11sts Ω resistance are formed formed by 20 resistances are respectively arranged, second step disc is made up of each II measuring disk and the II ' replacement dish of being made up of 10 10 Ω resistance, the brush of measuring disk is connected through lead with the brush of replacement dish on second step disc, the 3rd step disc is made up of each III measuring disk and the III ' replacement dish of being made up of 10 11 Ω resistance, and the brush of the brush of measuring disk and replacement dish is through 22 Ω resistance R on the 3rd step disc ₂Connect, the 4th dish is two slide wire discs, two slide wire resistance Standard resistance ranges all are 0～110 Ω, be that top is 0 Ω, end is 110 Ω, wherein one is IV measuring disk slip, another root is an IV ' 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 11 Ω, " 0 " indicating value of two slide wire disc index dials, dish slip of the IV ' replacement just and IV measuring disk slip the 0th contact, 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 IV ' replacement just and IV measuring disk slip the 10th contact, 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 dish brush connects DC potentiometer working power positive pole, and the I ' replacement is coiled the 20th contact and connected the II ' replacement and coil the 10th contact, and II measuring disk the 0th contact is 2132/11sts Ω resistance R through a resistance ₁The back is connected with I measuring disk the 0th contact, and it is 210890/11sts Ω resistance R through a resistance that the 0th contact is coiled in the I ' replacement ₃The back is coiled the 0th contact with the III ' replacement and is connected, the III ' replacement is coiled the 10th contact and is connected the IV ' replacement dish slip the 0th contact, IV measuring disk slip the 10th contact connects III measuring disk the 0th contact, and III measuring disk the 10th contact is connected with I measuring disk the 20th contact; I measuring disk brush connects sets up resistance R N hot end; Connect measured " U _X" two terminals, anodal terminal connects II measuring disk the 10th contact, the negative pole terminal is connected with IV measuring disk slip the 0th contact after through the double-point double-throw switch K that is connected to galvanometer G between two normally closed contacts.