Browse Prior Art Database

Field Detector using Machine Frame as Antenna Element

IP.com Disclosure Number: IPCOM000082312D
Original Publication Date: 1974-Nov-01
Included in the Prior Art Database: 2005-Feb-28
Document File: 2 page(s) / 30K

Publishing Venue

IBM

Related People

Calcavecchio, R: AUTHOR [+3]

Abstract

Computing systems may be sensitive to external transient electromagnetic events of sufficient magnitude, to cause the machine to produce an error or to otherwise malfunction. A record of the nature and magnitude of such transient electromagnetic fields, which illuminate the system in its operating environment, is useful in prescribing machine specification requirements and identification of individual operating environment excesses.

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Field Detector using Machine Frame as Antenna Element

Computing systems may be sensitive to external transient electromagnetic events of sufficient magnitude, to cause the machine to produce an error or to otherwise malfunction. A record of the nature and magnitude of such transient electromagnetic fields, which illuminate the system in its operating environment, is useful in prescribing machine specification requirements and identification of individual operating environment excesses.

This system detects and records the magnitude of transient electromagnetic fields, using the machine itself as the antenna element.

An electromagnetic field illuminating the machine produces a current on the surface of the machine frame 1. Part of this current flows on the shield or other surface structure of any external cable 2, which is connected to the machine frame. This current or voltage is thus a measure of the electromagnetic field. A radio frequency (RF) probe 3, coupled to cable 2, provides an output which is connected to low-pass filter 5 via coaxial transmission line 4. Filter 5 rejects signals above about 100 megahertz, which are not useful in the analysis. The waveform at the output of filter 5 is fed to a peak detector 6 and thence to a multichannel analyzer 7. Analyzer 7 records the number of transient events occurring within discreet amplitude intervals.

In the illustrated system, elements 5, 6 and 7 are outside the machine frame. This may be convenient for applic...