DE920746C - Procedure for measuring the difference between two frequencies - Google Patents

Procedure for measuring the difference between two frequencies

Info

Publication number
DE920746C
DE920746C DEA18236D DEA0018236D DE920746C DE 920746 C DE920746 C DE 920746C DE A18236 D DEA18236 D DE A18236D DE A0018236 D DEA0018236 D DE A0018236D DE 920746 C DE920746 C DE 920746C
Authority
DE
Germany
Prior art keywords
frequency
difference
frequencies
measuring
difference frequency
Prior art date
Legal status (The legal status 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 status listed.)
Expired
Application number
DEA18236D
Other languages
German (de)
Inventor
Volker Dr-Ing Aschoff
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
AEG AG
Original Assignee
AEG 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 AEG AG filed Critical AEG AG
Priority to DEA18236D priority Critical patent/DE920746C/en
Application granted granted Critical
Publication of DE920746C publication Critical patent/DE920746C/en
Expired legal-status Critical Current

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Classifications

    • GPHYSICS
    • G01MEASURING; TESTING
    • G01RMEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R23/00Arrangements for measuring frequencies; Arrangements for analysing frequency spectra

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  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Measuring Frequencies, Analyzing Spectra (AREA)

Description

Es besteht häufig die Aufgabe, die Frequenz zweier elektrischer Schwingungen miteinander zu vergleichen. Dies geschieht üblicherweise durch Modulation der beiden Frequenzen miteinander und Messung der hierbei entstehenden Differenzfrequenz. Die zur Messung einer solchen Differenz frequenz bisher bekannten Verfahren eignen sich nun ihrer Natur nach nur für einen beschränkten Frequenzbereich. Mißt man beispielsweise mit Hilfe eines Galvanometers, so lassen sich extrem tiefe Frequenzen bis zur Frequenz Null herunter ohne Schwierigkeiten messen; Frequenzen, die über der der mechanischen Eigenresonanz des Galvanometeranzeigesystems entsprechenden Frequenz liegen, können jedoch nicht erfaßt werden. Umgekehrt lassen sich die bekannten Frequenzmeßbrücken sowohl wie die ebenfalls bekannten direkt anzeigenden Frequenzmeßgeräte ohne allzu großen Aufwand nur für die Messung von Frequenzen ausbilden, die oberhalb eines Mindestwertes von einigen Hertz liegen. There is often the task of determining the frequency of two electrical oscillations to compare with each other. This is usually done by modulating the two Frequencies with each other and measurement of the resulting difference frequency. the previously known methods are suitable for measuring such a difference frequency now by their nature only for a limited frequency range. If you measure, for example With the help of a galvanometer, extremely low frequencies down to the frequency Measure zero down without difficulty; Frequencies above that of the mechanical Natural resonance of the galvanometer display system corresponding frequency can however, cannot be detected. The known frequency measuring bridges can be reversed as well as the also known direct display frequency meters without too much train great effort only for the measurement of frequencies that are above a Minimum value of a few Hertz.

Tritt nun beispielsweise die Aufgabe auf, einen elektrischen Generator veränderlicher Frequenz innerhalb eines größeren Frequenzbereiches mit einem Normalfrequenzgenerator zu vergleichen, so müßte man im Anschluß an die Modulation der zu vergleichenden Frequenzen je nach der Größe der Abweichung beider Frequenzen das eine oder das andere Meßverfahren benutzen, was sehr umständlich und zeitraubend wäre. Dieser Nachteil wird durch die vorliegende Erfindung vermieden. For example, if the task now occurs, an electrical generator variable frequency within a larger frequency range with a normal frequency generator to compare, one would have to follow the modulation of the one to be compared Frequencies depending on the size of the deviation of the two frequencies one or that use other measuring methods, which would be very cumbersome and time-consuming. This The present invention avoids the disadvantage.

Gegenstand der Erfindung ist ein Verfahren zur Messung der Differenz zweier Frequenzen. Erfindungsgemäß wird in dem Pentodensystem einer an sich bekannten Abstimmanzeigeröhre (magisches Auge), deren Steuergitter die eine Frequenz J1 und deren Schirmgitter die andere Frequenz, zugeführt wird, durch Modulation in bekannter Weise die Summen- und die Differenzfrequenz fi + 2 bzw. f, -f2 der beiden Frequenzen gebildet und die Differenzfrequenz Ji - ft2 bei sehr kleinen Werten durch Auszählen der mit dem Auftreten der Differenzfrequenz zwangsweise verbundenen periodischen Schwankungen des Leuchtwinkels ermittelt, bei größeren Werten jedoch über einen Tiefpaß TP geführt und mittels eines bekannten Frequenzmeßverfahrens gemessen. The invention relates to a method for measuring the difference two frequencies. According to the invention, one known per se is used in the pentode system Tuning display tube (magic eye), the control grid of which has a frequency J1 and whose screen grids the other frequency, supplied by modulation in a known manner Way the sum and the difference frequency fi + 2 or f, -f2 of the two frequencies and the difference frequency Ji - ft2 for very small values by counting the periodic inevitably associated with the occurrence of the difference frequency Fluctuations in the light angle determined, but for larger values over one Low-pass filter TP and measured by means of a known frequency measurement method.

Die Erfindung sei im folgenden an Hand eines in der Zeichnung dargestellten Ausführungsbeispieles näher erläutert. The invention is shown below with reference to one in the drawing Embodiment explained in more detail.

A bedeutet eine bekannte Abstimmanzeigeröhre, deren Anzeigesystem mit einer Pentode vereinigt ist, z. B. EFM II. Über die Klemmen I und Erde wird dem Steuergitter G1 der Röhre die Frequenz fl zugeführt, über die Klemmen 2 und Erde dem Schirmgitter G2 die Frequenzf2. Infolge der bekannten Modulationseigenschaft einer Pentode werden in deren Anodenstrom neben den Frequenzen tl und f2 auch die Frequenzen ft+2 und fif2 neu gebildet. Der Leuchtwinkel des Anzeigesystems wird nun durch diese neu entstehenden Frequenzen ebenfalls gesteuert. A means a known tuning indicator tube, its display system is associated with a pentode, e.g. B. EFM II. Via terminals I and earth the frequency fl supplied to the control grid G1 of the tube, via the terminals 2 and Earth the screen grid G2 the frequency f2. As a result of the well-known modulation property of a pentode are in its anode current not only the frequencies tl and f2 but also the Frequencies ft + 2 and fif2 formed anew. The light angle of the display system is now also controlled by these newly emerging frequencies.

Nimmt die Differenzfrequenz fi - ft2 sehr kleine Werte an (einige Hertz und darunter), so ist das Auge des Messenden in der Lage, die im Rhythmus dieser Frequenz erfolgenden Schwankungen des Leuchtwinkels wahrzunehmen, so daß durch Auszählen der Schwankungen pro Zeiteinheit die Differenzfrequenz ermittelt werden kann. Die gleichzeitig auftretenden Schwankungen des Leuchtwinkels, die durch die höher liegenden Frequenzen fl, 2 und fi + 2 bedingt sind, werden vom Messenden infolge der bekannten Trägheit des menschlichen Auges nicht wahrgenommen. If the difference frequency fi - ft2 takes on very small values (some Hertz and below), the eye of the person measuring is able to work in rhythm this frequency to perceive fluctuations in the light angle, so that the difference frequency is determined by counting the fluctuations per unit of time can be. The simultaneously occurring fluctuations in the light angle caused by the higher frequencies fl, 2 and fi + 2 are conditional, are determined by the person measuring not perceived due to the known sluggishness of the human eye.

Nimmt die Differenzfrequenz fi -fi größere Werte an, so daß das Auge des Beobachters den Schwankungen nicht mehr exakt folgen kann, so wird die Differenzfrequenz über einen entsprechend ausgebildeten Tiefpaß TP von den übrigen Frequenzen getrennt und den Klemmen 3 und 4 irgendeines der bekannten Frequenzmeßgeräte zugeführt, das die Differenzfrequenz mißt. Assumes the difference frequency fi -fi larger values, so that the eye of the observer can no longer follow the fluctuations exactly, the difference frequency becomes separated from the other frequencies by a correspondingly designed low-pass filter TP and applied to terminals 3 and 4 of any of the known frequency meters which measures the difference frequency.

Claims (1)

PATENTANSPRUCH: Verfahren zur Messung der Differenz zweier Frequenzen, dadurch gekennzeichnet, daß in dem Pentodensystem einer an sich bekannten Abstimmanzeigeröhre (magisches Auge), deren Steuergitter die eine Frequenz (fl) und deren Schirmgitter die andere Frequenz (f2) zugeführt wird, durch Modulation in bekannter Weise die Summe und die Differenz der beiden Frequenzen (tl + 2 bzw. fl - fB) gebildet wird und die Differenzfrequenz (fi -fi) bei sehr kleinen Werten durch Auszählen der mit dem Auftreten der Differenzfrequenz zwangsweise verbundenen periodischen Schwankungen des Leuchtwinkels ermittelt wird, während größere Werte der Differenzfrequenz über einen Tiefpaß geführt und mittels an sich bekannter Frequenzmeßverfahren gemessen werden. PATENT CLAIM: Method for measuring the difference between two frequencies, characterized in that in the pentode system a tuning indicator tube known per se (magic eye), whose control grid is one frequency (fl) and whose screen grid the other frequency (f2) is supplied by modulating in a known manner the The sum and the difference between the two frequencies (tl + 2 or fl - fB) is formed and the difference frequency (fi -fi) for very small values by counting the with the occurrence of the difference frequency inevitably associated periodic fluctuations the light angle is determined, while larger values of the difference frequency over a low-pass filter and measured by means of frequency measurement methods known per se will.
DEA18236D 1940-09-21 1940-09-21 Procedure for measuring the difference between two frequencies Expired DE920746C (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
DEA18236D DE920746C (en) 1940-09-21 1940-09-21 Procedure for measuring the difference between two frequencies

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DEA18236D DE920746C (en) 1940-09-21 1940-09-21 Procedure for measuring the difference between two frequencies

Publications (1)

Publication Number Publication Date
DE920746C true DE920746C (en) 1954-11-29

Family

ID=6924105

Family Applications (1)

Application Number Title Priority Date Filing Date
DEA18236D Expired DE920746C (en) 1940-09-21 1940-09-21 Procedure for measuring the difference between two frequencies

Country Status (1)

Country Link
DE (1) DE920746C (en)

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