The resolver is a highly accurate and highly dependable device for absolute position shaft encoding. Resolvers have a reliable track record of applications in aerospace, military and industry, where they have been used for decades for position sensing. Some of the common applications are radar antenna position sensing, missile guidance systems, NC machine position feedback, automotive stamping presses, 2 piece can manufacturing presses and packaging machines.
The resolver is designed to operate reliably under extremely hostile environments such as continuous mechanical shock, vibration, extreme temperature and humidity changes, oil mist, coolants, and solvents. The resolver is a passive transducer. It is a brushless rotary transformer with one rotor and two stator windings. The stator windings are electrically 90 degrees out of phase with each other.
As the shaft rotates, the relative position of the rotor and the stator windings change. Either the rotor or the two stator windings together can be used as the primary of the rotary transformer and the secondary will then produce an analog voltage corresponding to the shaft position.
LT-140 Absolute Linear Position Transducer
Absolute Linear Position Ultrasonic Position sensing No Moving Parts Accurate to 0.001" An ultrasonic linear transducer consists of an interface control module, a non-magnetic 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 non-magnetic 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 angles 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 do coder or a linear PLS. Magnetic fields normally generated by 60 Hz or 400Hz equipment will not affect the operation because these frequencies will be rejected by the narrow band-width detector utilized.
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