AT36640B - Contact device for sensitive measuring instruments. - Google Patents

Contact device for sensitive measuring instruments.

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Publication number
AT36640B
AT36640B AT36640DA AT36640B AT 36640 B AT36640 B AT 36640B AT 36640D A AT36640D A AT 36640DA AT 36640 B AT36640 B AT 36640B
Authority
AT
Austria
Prior art keywords
contact device
measuring instruments
sensitive measuring
contact
galvanometer
Prior art date
Application number
Other languages
German (de)
Original Assignee
W C Heraeus Fa
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 W C Heraeus Fa filed Critical W C Heraeus Fa
Application granted granted Critical
Publication of AT36640B publication Critical patent/AT36640B/en

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Description

  

   <Desc/Clms Page number 1> 
 



  Kontaktvorrichtung für empfindliche Messinstrumente. 



   Bei empfindlichen Messinstrumenten, wie es die jetzt vielfach verwendeten Instrumente mit   Drehspule   nach dem Prinzip von   D'Arsonval   sind, bietet es grosse Schwierigkeiten, mit dem Zeiger einen elektrischen Kontakt zu bewirken, der beispielsweise den Stromkreis einer Alarmvorrichtung zu schliessen bestimmt ist. Eine dieser Schwierigkeiten liegt darin, dass selbst bei Verwendung von Edelmetallen wie    Platinoder Iridinm an der   Kontaktstelle ein Klebenbleiben des Zeigers auf der Kontaktvorrichtung leicht, stattfindet. 



   Die Erfindung bezweckt nun, diesen Übelstand zu beseitigen. Zur Erläuterung, dient die Zeichnung. Dem Galvanometer G wird die Sekundärspule eines Transformators J parallel geschaltet, welche dem zu messenden Gleichstrom S einen bestimmten hohen Widerstand entgegensetzt, der bei der Eichung des Instruments berücksichtigt werden kann. Die Kontaktleitung geht durch ein Relais R, welches eine Klingelleitung schliesst, und ausserdem durch die Primärspule des Transformators. Die Polarität des Kontaktstromes wird so gewählt, dass im Moment der Berührung des Zeigers mit dem Kontakt C in der Sekundärspule und also auch in dem Stromkreis des Galvanometers ein Induktionsstrom erzeugt wird, welcher dem Galvanometerstrom entgegengerichtet ist und also den Zeiger vom Kontakt wieder abstösst.

   Es'wird dadurch ein unsichere Kontakt und ein   Klobenbleiben   vollständig ver-   mieden.   

**WARNUNG** Ende DESC Feld kannt Anfang CLMS uberlappen**.



   <Desc / Clms Page number 1>
 



  Contact device for sensitive measuring instruments.



   In the case of sensitive measuring instruments, such as the instruments with rotating coils based on the D'Arsonval principle, which are now widely used, it is very difficult to make an electrical contact with the pointer, which is intended to close the circuit of an alarm device, for example. One of these difficulties is that even if noble metals such as platinum or iridine are used at the contact point, the pointer can easily stick to the contact device.



   The invention now aims to eliminate this drawback. The drawing serves as an explanation. The galvanometer G is connected in parallel to the secondary coil of a transformer J, which opposes the direct current S to be measured with a certain high resistance which can be taken into account when calibrating the instrument. The contact line goes through a relay R, which closes a bell line, and also through the primary coil of the transformer. The polarity of the contact current is chosen so that at the moment the pointer touches contact C in the secondary coil and thus also in the galvanometer circuit, an induction current is generated which is opposite to the galvanometer current and thus repels the pointer from the contact.

   Unsafe contact and sticking are thereby completely avoided.

** WARNING ** End of DESC field may overlap beginning of CLMS **.

 

Claims (1)

PATENT-ANSPRUCH : Kontaktvorrichtung für empfindliche Messinstrumente, dadurch gekennzeichnet, dass dem Galvanometer die Sekundärspule eines Transformators parallel geschaltet ist, dessen Primärspule in dem Stromkreis der Kontaktvorrichtung liegt. EMI1.1 **WARNUNG** Ende CLMS Feld Kannt Anfang DESC uberlappen**. PATENT CLAIM: Contact device for sensitive measuring instruments, characterized in that the galvanometer is connected in parallel with the secondary coil of a transformer whose primary coil is in the circuit of the contact device. EMI1.1 ** WARNING ** End of CLMS field may overlap beginning of DESC **.
AT36640D 1907-04-27 1907-12-11 Contact device for sensitive measuring instruments. AT36640B (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DE194676D 1907-04-27

Publications (1)

Publication Number Publication Date
AT36640B true AT36640B (en) 1909-03-26

Family

ID=5745595

Family Applications (1)

Application Number Title Priority Date Filing Date
AT36640D AT36640B (en) 1907-04-27 1907-12-11 Contact device for sensitive measuring instruments.

Country Status (1)

Country Link
AT (1) AT36640B (en)

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