Browse Prior Art Database

Surface Current Probe

IP.com Disclosure Number: IPCOM000103291D
Original Publication Date: 1990-Sep-01
Included in the Prior Art Database: 2005-Mar-17
Document File: 1 page(s) / 45K

Publishing Venue

IBM

Related People

Smith, AA, Jr: AUTHOR

Abstract

A surface current probe for measuring radio-frequency (RF) currents on DC power distribution bus bars inlarge computer systems is shown in the Fig. The probe is constructed form a block of ferreite material 1 having a number of tuens N of insulated wire 2 wuond arount it. The wire ends are connected to a coaxial RF connector 3 which is glued or potted to the ferrite block for mechanical stability. A dielectric base 4 is glued to the botttom surface of the probe to prevent the wires 2 from shorting to the bus bar 5.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 99% of the total text.

Surface Current Probe

      A surface current probe for measuring radio-frequency (RF)
currents on DC power distribution bus bars inlarge computer systems
is shown in the Fig.  The probe is constructed form a block of
ferreite material 1 having a number of tuens N of insulated wire 2
wuond arount it.  The wire ends are connected to a coaxial RF
connector 3 which is glued or potted to the ferrite block for
mechanical stability.  A dielectric base 4 is glued to the botttom
surface of the probe to prevent the wires 2 from shorting to the bus
bar 5.

      In use, the RF connector 3 is connected to t spectrum analyzer,
interference analyzer or oscilloscope via a coaxial cable.  The probe
is pressed against the bus bar 5 with the turns of wire 2 aligned
with the direction of current flow.  A voltage is induced in the
turns of wire by the magnetic field which is proportional to and
orthogonal to the RF current flowing on the bus bar.  The ferrite
material increases the fjox density and thereby the voltage induced
in the N turns of wire.  The transfer impedance of the probe is
claibrated by measuring the output voltage produced by a known
surface current.

      In addition to measuring currents on bus bars, the small size
and footprint of the surface current probe allows measurements of
currents on frame members, conductors and surfaces which are
inaccessible to conventional clamp-on current probes and half-roroid
surface current probes.

      Disclosed an...