resolver decoder specifications - Steven Engineering

LT140 LINEAR ULTRASONIC POSITION
TRANSDUCER
ABSOLUTE POSITION TRANSDUCER
◆ Absolute linear position
◆ Ultrasonic position sensing; no moving parts
◆ Easy to install
SECTION
A
◆ Accurate to 0.001" (0.025 mm)
LT140
Principle of Operation
An ultrasonic linear transducer consists of an interface control
module, a nonmagnetic stainless steel rod with sensing head
and a "doughnut" magnet. An electrical interrogating pulse,
generated in the interface control module, creates a magnetic
field around the conducting element housed inside a waveguide
which in turn is enclosed in the nonmagnetic stainless
steel transducer rod. The "doughnut-shaped" permanent magnet,
mechanically representative of machine position, reacts
with this generated field producing a mechanical force at right
angle to the conducting element. This force causes a twist (torsional
strain) which travels back the length of the rod. These
strain pulses arrive at a fixed reference a certain time interval
later and this time delay from the interrogating pulse indicates
the linear position of the "doughnut" magnet. These precise
time-based pulses are then converted to digital output inside a
linear decoder or a linear PLS.
Magnetic fields normally generated by 60 or 400 Hz equipment
will not affect the operation because these frequencies
will be rejected by the narrow bandwidth detector used.
Normally the transducer rod is fixed and the "doughnut" magnet
moves with the moving part of the machine. However, this
can be reversed if desired. The relative displacement between
the two parts provides the output signal.
Position Transducers/Sensors
800-TEC-ENGR
www.avg.net
A-17