AT209424B - Loop resistance meter - Google Patents

Loop resistance meter

Info

Publication number
AT209424B
AT209424B AT446057A AT446057A AT209424B AT 209424 B AT209424 B AT 209424B AT 446057 A AT446057 A AT 446057A AT 446057 A AT446057 A AT 446057A AT 209424 B AT209424 B AT 209424B
Authority
AT
Austria
Prior art keywords
loop resistance
resistance meter
voltage
bridge
measuring device
Prior art date
Application number
AT446057A
Other languages
German (de)
Inventor
Odo Dipl Ing Erb
Original Assignee
Siemens Ag
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Siemens Ag filed Critical Siemens Ag
Priority to AT446057A priority Critical patent/AT209424B/en
Application granted granted Critical
Publication of AT209424B publication Critical patent/AT209424B/en

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  • Measurement Of Resistance Or Impedance (AREA)

Description

  

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  Schleifenwiderstandsmessgerät 
 EMI1.1 
 

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 beiDie Brücke wird zunächst bei offenem Schalter 7 mit Hilfe der Widerstände 11 und 12 so abgestimmt, dass das Instrument 13 stromlos ist. An den Klemmen 3 und 4 herrscht die Spannung   U. Nun   wird der Schalter 7 geschlossen, wodurch über die gerade eingeschaltete Stufe des Belastungswiderstandes Rb Strom fliesst und die Spannung an den Klemmen 3, 4 auf den Wert Db absinkt. Damit ändert sich auch die Speisespannung der Brückenspannung 1. Für diese neue Spannung ist die Brücke jedoch infolge der Nichtlinearität wenigstens eines ihrer Widerstände nicht mehr abgestimmt, so dass an der Brückendiagonale eine Differenzspannung auftritt, die einen Ausschlag des Anzeigeinstrumentes 13 veranlasst.

   Aus diesem kann im Zusammenhang mit der bekannten Grösse des vorgeschalteten Belastungswiderstandes Rb auf den Schleifenwiderstand geschlossen werden. Das erfindungsgemässe Messgerät zeichnet sich vor allem dadurch aus, dass bereits kleine Spannungsänderungen zu grossen Ausschlägen am Instrument führen, so dass mit kleinen Stromstärken bei der Messung das Auslangen gefunden werden kann.



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  Loop resistance meter
 EMI1.1
 

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 The bridge is first adjusted with the switch 7 open with the help of resistors 11 and 12 so that the instrument 13 is de-energized. The voltage U prevails at terminals 3 and 4. Switch 7 is now closed, causing current to flow through the stage of the load resistor Rb that has just been switched on and the voltage at terminals 3, 4 drops to the value Db. This also changes the supply voltage of the bridge voltage 1. For this new voltage, however, the bridge is no longer tuned due to the non-linearity of at least one of its resistors, so that a differential voltage occurs at the bridge diagonal, which causes the display instrument 13 to deflect.

   From this, in connection with the known size of the upstream load resistance Rb, conclusions can be drawn about the loop resistance. The measuring device according to the invention is particularly distinguished by the fact that even small voltage changes lead to large deflections on the instrument, so that the measurement can be made with small currents.

Claims (1)

PATENTANSPRUCH : Schleifenwiderstandsmessgerät, bei dem der durch Zuschaltung eines Belastungswiderstandes verursachte Spannungsabfall die Messwertanzeige vermittelt, dadurch gekennzeichnet, dass als Messteil eine gegebenenfalls über einen Gleichrichter gespeiste an sich bekannte Brückenschaltung mit wenigstens einem nichtlinearen, einen Festkörper als Leiter enthaltenden Widerstand, vorgesehen ist, in deren einer EMI2.1 PATENT CLAIM: Loop resistance measuring device in which the voltage drop caused by the connection of a load resistor mediates the measured value display, characterized in that a known bridge circuit, possibly fed via a rectifier and with at least one non-linear resistor containing a solid as a conductor, is provided as the measuring part one EMI2.1
AT446057A 1957-07-08 1957-07-08 Loop resistance meter AT209424B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AT446057A AT209424B (en) 1957-07-08 1957-07-08 Loop resistance meter

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
AT446057A AT209424B (en) 1957-07-08 1957-07-08 Loop resistance meter

Publications (1)

Publication Number Publication Date
AT209424B true AT209424B (en) 1960-06-10

Family

ID=3564305

Family Applications (1)

Application Number Title Priority Date Filing Date
AT446057A AT209424B (en) 1957-07-08 1957-07-08 Loop resistance meter

Country Status (1)

Country Link
AT (1) AT209424B (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1287211B (en) * 1967-02-13 1969-01-16 Friedrich Dipl Ing Circuit for measuring the internal resistance of an alternating current network

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1287211B (en) * 1967-02-13 1969-01-16 Friedrich Dipl Ing Circuit for measuring the internal resistance of an alternating current network

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