Warner Electric B30 Single Range Tensioncells - Manual (Page 5)

5 Warner Electric • 800-825-9050 P-2012-4 • 819-0404
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.030” 0.0 .030”
3.5 V. Set Point
Tension Compression
LVDT Output vs Deflection
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V
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Deflection
Figure 4
With Warner Electric LVDTs, the input and
output circuits are electrically isolated from each
other and from the mechanical structure of the
tensioncell. Thus, they may be used in "floating
ground" or "ground return" systems. This
eliminates the need for extra circuit boards
which are required for most straingage loadcells.
Tensioncells are factory adjusted to provide an
offset voltage with no load applied (no
deflection). Using an input of 24 volts DC, the
LVDT is set to provide an output of 3.5 volts into
a resistive load of not less than 100,000 ohms.
The voltage resulting from the maximum rated
deflection then adds to or subtracts from the 3.5
volt offset. This results in an output voltage of
3.5 to 6.5 volts in the Compression Mode and
3.5 to 0.5 volts in the Tension Mode. (See
Figure 4)
While acceptable performance may be obtained
over an input voltage range of 6.0 to 30.0 volts
DC, the output voltage will vary in direct
proportion to the input voltage. Because of
this, the use of a well regulated constant voltage
power supply is essential for accurate and
repeatable tension measurement.
In standard applications, where two Tensioncells
are used, the inputs may be connected in
parallel allowing the Tensioncells to be excited
from the same power supply. The LVDT outputs
are then summed to obtain a signal representing
the strip tension and tare loads distributed
across the roll.
Description of Operation
The total resultant load per cell (RF) is calculated
by resolving all force vectors acting upon the
Tensioncell, with respect to the Loading Line
(OL). (RF) is the resultant of both TENSION and
TARE loads, PER CELL!! (See Figure 5)
The intrinsic design of Warner Electric Tension-
cells allows the location of the Resultant Load of
Strip Tension (H) on any angle with respect to
the Load Line (OL). Note, however, that the Total
Force vector (RF) must always be calculated on
the line (OL).
Nominal
L R
Figure 5