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US 4,901,009 AGranted
Method and device for the automatic recording of signal curves
AssigneeAsea Brown Boveri AG
InventorsWolfgang Schultze, Werner Todter, Reinhold Kern
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AssigneeAsea Brown Boveri AG
InventorsWolfgang Schultze, Werner Todter, Reinhold Kern
Estimating the term…
In a digital oscilloscope, the recording of transients exceeding a predetermined tolerance range is to be provided by simple means. A method and a device for carrying out this method are provided in which two envelope curves are stored in an envelope curve memory and these are then compared with cyclically repetitive amplitude samples of a signal curve. A trigger signal ensures that the signal curve containing the disturbance is served if one of the signal curves exceeds the tolerance range delimited by the envelope curves, which is the case, in particular, when interference signals occur. This curve can then be displayed for analysis on the screen. The invention can be applied within the context of digital measuring technology wherever signal curves are recorded and instantaneous disturbances must be detected.
Method for recording signal curves which comprises:
Device for recording signal curves, comprising an A/D converter for converting analog signal curves into digital amplitude samples, a processor for determining an operational sequence, a signal reproduction circuit connected to said processor for displaying an image of the signal curve on a screen, a signal memory connected to said processor to be continuously overwritten with cyclically repetitive amplitude samples of a signal curve, an envelope curve memory connected to said processor for receiving two envelope curves calculated by said processor from amplitude samples of a selected signal curve, a comparison circuit connected to said A/D converter and to said memories for continuously synchronously comparing amplitude samples from said A/D converter with corresponding amplitude samples from said envelope curve memory, and a control circuit connected between said comparison circuit and said processor for causing the instantaneous signal curve to be saved after an amplitude sample of the signal curve has exceeded one of the envelope curves.
Device according to claim, 3 wherein said comparison circuit includes first and second registers forming an input of said comparison circuit, said registers having inputs and outputs, said input of said first register receiving the amplitude samples of the signal curve from said A/D converter and said input of said second register receiving the amplitude samples of the envelope curves from said envelope curve memory, a comparator having inputs connected to said outputs of said registers for receiving respective A and B amplitude samples, said comparator having a first output switching to "high" when the amplitude samples A are less than the amplitude samples B and a second output switching to "high" when the amplitude samples A are greater than the amplitude samples B, and a multiplexer connected to said outputs of said comparator for delivering a switching signal as soon as one of said comparator outputs switches to "high".
Dependencies are inferred from the claim text.