Glossary of Terms
Dielectric withstanding voltage
Ability to withstand under prescribed conditions, a
speci?ed potential of a given characteristic
between the terminals of each cup and the exposed
conducting surfaces of the potentiometer, or
between the terminals of each cup and the
terminals of every other cup in the potentiometer
without exceeding a speci?ed leakage current.
Effective electrical angle (EEA)
The total amount of angular input rotation over
which the output ratio actually varies.
Encoder
A device that produces a digital output signal;
typically an incremental quadrature, binary, or
absolute output signal. This device eliminates the
need for analog-to-digital (A/D) signal
conversion.
End resistance
The resistance measured between the wiper
terminal and end terminal with the shaft
positioned at the corresponding end of mechanical
travel.
End voltage (non-wirewound)
The voltage between the wiper terminal and an
end terminal when the shaft is positioned at the
corresponding theoretical end point. End voltage is
Gang
An assembly of two or more cups on a common
operating shaft.
Gray code
Binary code where only 1-bit changes logic state
from one angular position to the next (a.k.a.
Absolute code).
Hybritron?
A hybrid element consisting of a wirewound
element with a conductive plastic coating; this
element will exhibit the stability characteristics of
a wirewound element with the long operational
life of a conductive plastic element.
Incremental
The repetitive pattern of logic states (High, 1,
true/Low, 0 false) in the output signal of an
encoder occurring with each successive electrical
cycle of resolution.
Index
The output signal of an index channel is normally
a single pulse per revolution. This output can be
used to indicate a “zero” or “home” position in the
shaft rotation. Adding an index channel to an
incremental encoder allows the encoder to provide
absolute position. (Also referred to as “Index
channel” and “Z-channel”)
expressed as a percent of the total applied voltage.
Independent linearity
End voltage (wirewound)
The voltage between the wiper terminal and an
end terminal when the shaft is positioned at the
corresponding end point. End voltage is expressed
The maximum deviation of the actual wiper
output function from a straight reference line with
its slope and position chosen to minimize
deviations.
as a percent of the total applied voltage.
Interpolation
Equivalent noise resistance (ENR)
The variation in resistance between the wiper and
a wirewound resistive element that occurs when
the wiper is energized with a speci?ed current and
moved over the electrical travel in either direction
at a speci?ed speed (does not include the effects of
roll-on or roll-off).
A multiplication technique used to increase
encoder resolution.
Insulation resistance
The resistance to a speci?ed impressed DC voltage
between the terminals of each cup and the exposed
conducting surfaces of the potentiometer, or
between the terminals of each cup and the
terminals of every other cup in the potentiometer,
under prescribed conditions.
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