DE3909946A1 - Circuit arrangement for evaluating an AF signal - Google Patents

Circuit arrangement for evaluating an AF signal

Info

Publication number
DE3909946A1
DE3909946A1 DE19893909946 DE3909946A DE3909946A1 DE 3909946 A1 DE3909946 A1 DE 3909946A1 DE 19893909946 DE19893909946 DE 19893909946 DE 3909946 A DE3909946 A DE 3909946A DE 3909946 A1 DE3909946 A1 DE 3909946A1
Authority
DE
Germany
Prior art keywords
signal
comparator
inverting input
circuit arrangement
evaluating
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.)
Withdrawn
Application number
DE19893909946
Other languages
German (de)
Inventor
Martin Englmeier
Hans-Werner Weber
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.)
Telefunken Electronic GmbH
Original Assignee
Telefunken Electronic GmbH
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 Telefunken Electronic GmbH filed Critical Telefunken Electronic GmbH
Priority to DE19893909946 priority Critical patent/DE3909946A1/en
Publication of DE3909946A1 publication Critical patent/DE3909946A1/en
Withdrawn legal-status Critical Current

Links

Classifications

    • GPHYSICS
    • G01MEASURING; TESTING
    • G01RMEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R19/00Arrangements for measuring currents or voltages or for indicating presence or sign thereof
    • G01R19/0084Arrangements for measuring currents or voltages or for indicating presence or sign thereof measuring voltage only

Abstract

The invention relates to a circuit arrangement for evaluating an AF signal having a comparator and an evaluation unit, the AF signal being supplied to the non-inverting input and the comparator being operated with an asymmetric supply voltage. According to the invention, a resistor connects the non-inverting input to the inverting input, and the inverting input is connected to the reference potential of the circuit via a capacitor. The DC component of the AF signal is thereby applied to the inverting input as a biasing voltage, so that the working point of the comparator is shifted correspondingly to the DC component of the AF signal.

Description

Die Erfindung betrifft eine Schaltungsanordnung zur Auswertung eines NF-Signales gemäß dem Oberbegriff des Anspruches 1.The invention relates to a circuit arrangement for Evaluation of an LF signal according to the generic term of Claim 1.

Eine herkömmliche Schaltungsanordnung mit einem Kompa­ rator 1 und einer Auswerteeinheit 2 zeigt die Fig. 1, die eine Eingangssignalquelle 3 enthält. Ein NF-Signal wird von der Eingangssignalquelle 3 dem nichtinvertie­ renden Eingang des Komparators 1 zugeführt, während der invertierende Eingang dieses Komparators 1 direkt mit dem Bezugspotential der Schaltung verbunden ist. Der Komparator 1 wird nur aus einzigen Spannungsquelle U EE gespeist. Der Ausgang des Komparators 1 ist mit der Auswerteeinheit 2 verbunden.A conventional circuit arrangement with a comparator 1 and an evaluation unit 2 is shown in FIG. 1, which contains an input signal source 3 . An LF signal is supplied from the input signal source 3 to the non-inverting input of the comparator 1 , while the inverting input of this comparator 1 is connected directly to the reference potential of the circuit. The comparator 1 is only fed from a single voltage source U EE . The output of the comparator 1 is connected to the evaluation unit 2 .

Diese Schaltungsanordnung weist jedoch folgenden Nach­ teil auf. Liegt das Potential des invertierenden Ein­ ganges auf dem Bezugspotential der Schaltung und weist der Komparator eine negative Offset-Spannung auf, so befindet sich der Komparator immer an der positiven Grenze des Aussteuerbereiches, falls am nichtinvertie­ renden Eingang ein positives NF-Signal anliegt. Dadurch ist eine Auswertung des NF-Signales nicht möglich.However, this circuit arrangement shows the following part on. Is the potential of the inverting on ganges at the reference potential of the circuit and points the comparator has a negative offset voltage, so the comparator is always on the positive Limit of the control range, if on non-inverted A positive NF signal is present at the input. Thereby an evaluation of the LF signal is not possible.

Die Aufgabe der Erfindung besteht daher darin, eine Schaltungsanordnung der eingangs genannten Art derart auszubilden, daß der Arbeitspunkt des Komparators in Abhängigkeit von der Größe des anliegenden NF-Signals gleitend verschoben wird.The object of the invention is therefore a Circuit arrangement of the type mentioned above train that the operating point of the comparator in Depends on the size of the LF signal present is slid.

Diese Aufgabe wird gemäß den kennzeichnenden Merkmalen des Anspruches 1 gelöst.This task is carried out according to the characteristic features of claim 1 solved.

Bei der erfindungsgemäßen Schaltungsanordnung wird der Gleichspannungsanteil des NF-Signales dem invertieren­ den Eingang des Komparators zugeführt, so daß sich die Schaltschwelle des Komparators in Abhängigkeit vom Gleichspannungsanteil des NF-Signales verschiebt.In the circuit arrangement according to the invention Invert the DC voltage component of the LF signal fed the input of the comparator, so that the Switching threshold of the comparator depending on DC voltage component of the LF signal shifts.

Im folgenden soll ein Ausführungsbeispiel der erfin­ dungsgemäßen Schaltungsanordnung gemäß Fig. 2 die Er­ findung näher erläutern.In the following an embodiment of the inventive circuit arrangement according to FIG. 2, he will explain the invention in more detail.

Bei dem Ausführungsbeispiel gemäß Fig. 2 ist mit den Bezugszeichen 1 und 2 ein Komparator und eine Auswerte­ einheit bezeichnet, wobei der Komparator nur mit einer Versorgungsspannung +U EE betrieben wird und dessen Aus­ gang mit der Auswerteeinheit 2 verbunden ist. Dem nicht­ invertierenden Eingang des Komparators 1 wird über eine Eingangssignalquelle 3 das einen positiven Gleichspan­ nungsanteil aufweisende NF-Signal zugeführt. Ein aus der Reihenschaltung aus einem Kondensator C 1 und einem Widerstand R 1 bestehendes Siebglied verbindet den nicht­ invertierenden Eingang des Komparators 1 mit dem Bezugs­ potential der Schaltung. Der Gleichspannungsanteil des NF-Signales wird mit Hilfe dieses Siebgliedes ausgesiebt und dem Komparator 1 zugeführt, in dem der Verbindungs­ punkt des Kondensators C 1 mit dem Widerstand R 1 an den invertierenden Eingang des Komparators 1 angeschlossen ist.In the exemplary embodiment according to FIG. 2, the reference numerals 1 and 2 denote a comparator and an evaluation unit, the comparator being operated only with a supply voltage + U EE and the output of which is connected to the evaluation unit 2 . The non-inverting input of the comparator 1 is supplied via an input source 3, a positive DC clamping voltage component having LF signal. A filter element consisting of a series circuit consisting of a capacitor C 1 and a resistor R 1 connects the non-inverting input of the comparator 1 to the reference potential of the circuit. The DC voltage component of the LF signal is sieved with the help of this filter element and fed to the comparator 1 , in which the connection point of the capacitor C 1 with the resistor R 1 is connected to the inverting input of the comparator 1 .

Durch diese Vorspannung des invertierenden Einganges des Komparators 1 verschiebt sich die Schaltschwelle des Komparators in Abhängigkeit vom Gleichspannungsan­ teil des NF-Signales. Hierdurch wird die Empfindlich­ keit der nachfolgenden Auswerteeinheit gesteigert, da der Einfluß fertigungsbedingter Komparator-Offset-Span­ nungen bei der Auswertung kleiner NF-Signalpegel ver­ mindert wird.This bias of the inverting input of the comparator 1 shifts the switching threshold of the comparator as a function of the DC voltage part of the LF signal. This increases the sensitivity of the subsequent evaluation unit, since the influence of manufacturing-related comparator offset voltages is reduced during the evaluation of low LF signal levels.

Claims (1)

Schaltungsanordnung zur Auswertung eines NF-Signales mit einem Komparator (1) und einer Auswerteeinheit (2), wobei dem nichtinvertierenden Eingang (+) das NF-Signal zugeführt ist, und der Komparator (1) mit einer Versor­ gungsspannung (U EE) betrieben wird, dadurch gekennzeich­ net, daß ein Widerstand (R) den nichtinvertierenden Eingang (+) mit dem invertierenden Eingang (-) verbin­ det, und daß der invertierende Eingang (-) über einen Kondensator (C) an das Bezugspotential der Schaltung angeschlossen ist.Circuit arrangement for evaluating an LF signal with a comparator ( 1 ) and an evaluation unit ( 2 ), the non-inverting input (+) being supplied with the LF signal, and the comparator ( 1 ) being operated with a supply voltage (U EE ) , characterized in that a resistor ( R ) connects the non-inverting input (+) to the inverting input (-), and that the inverting input (-) is connected via a capacitor ( C ) to the reference potential of the circuit.
DE19893909946 1989-03-25 1989-03-25 Circuit arrangement for evaluating an AF signal Withdrawn DE3909946A1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
DE19893909946 DE3909946A1 (en) 1989-03-25 1989-03-25 Circuit arrangement for evaluating an AF signal

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DE19893909946 DE3909946A1 (en) 1989-03-25 1989-03-25 Circuit arrangement for evaluating an AF signal

Publications (1)

Publication Number Publication Date
DE3909946A1 true DE3909946A1 (en) 1990-09-27

Family

ID=6377265

Family Applications (1)

Application Number Title Priority Date Filing Date
DE19893909946 Withdrawn DE3909946A1 (en) 1989-03-25 1989-03-25 Circuit arrangement for evaluating an AF signal

Country Status (1)

Country Link
DE (1) DE3909946A1 (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE19602243A1 (en) * 1996-01-23 1997-07-24 Teves Gmbh Alfred Circuit arrangement for adapting an active sensor to an evaluation circuit
CN104198801A (en) * 2014-07-14 2014-12-10 珠海格力电器股份有限公司 AC voltage sampling circuit and AC voltage sampling method

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2346933A1 (en) * 1973-09-18 1975-04-03 Siemens Ag Comparator set-up for voltages with threshold value behaviour - has two sum-and-difference amplifiers for each comparator input
FR2246876A1 (en) * 1973-10-04 1975-05-02 Lignes Telegraph Telephon

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2346933A1 (en) * 1973-09-18 1975-04-03 Siemens Ag Comparator set-up for voltages with threshold value behaviour - has two sum-and-difference amplifiers for each comparator input
FR2246876A1 (en) * 1973-10-04 1975-05-02 Lignes Telegraph Telephon

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
- US-Z: MARKUS, J.: Electronic Circuits Manual, McGraw-Hill, 1971, S. 121,127 *
GULITZ, H.: Schwimmender Fensterkomaparator. In: Elektor, Juli/August 1987, S. 79 *

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE19602243A1 (en) * 1996-01-23 1997-07-24 Teves Gmbh Alfred Circuit arrangement for adapting an active sensor to an evaluation circuit
CN104198801A (en) * 2014-07-14 2014-12-10 珠海格力电器股份有限公司 AC voltage sampling circuit and AC voltage sampling method
CN104198801B (en) * 2014-07-14 2017-05-31 珠海格力电器股份有限公司 Alternating voltage sampling circuit and method

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Legal Events

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8139 Disposal/non-payment of the annual fee