Potentiometers, or pots, are a mainstay when it comes to position measurement. Recent advancements are boosting their capabilities and expanding their uses. A pot refers to a three-terminal variable resistor in a circuit. It comes indifferent types. Two of the most used in aerospace and medical fields are the digital and rotary pots.
Many believe that pots are pushed aside in favor of digital devices, like encoder and resolvers. The technical advances have improved potentiometer regaining the top spot as a useful device in aerospace and medical applications.
A digital pot allows control of voltage splitter with digital signals. It comes from either a digital-to-analog converter or a resistor ladder integrated circuit. Every step on the resistor ladder has its own switch that can connect this step to its output terminal where bit value indicates the number of steps.
While it is quite similar to a normal pot, SpectraSymbol clarifies these are constrained by current limits in the range of tens of milliamperes. Most digital pots limit the input voltage range to the digital supply range. This makes use of additional circuitry required to replace a conventional pot. Instead of the seemingly continuous control from a multi-turn resistive potentiometer, digital pots have discrete steps in resistance.
Rotary pots feature contact technology in a rugged, yet small package weight and size. Other features include resistance to electromagnetic interference, temperature stability and the ability to work with very high and low operating temperatures.
These are available in wire wound, hybrid configurations and conductive plastic. It comes in single or multi-turn configurations depending on the number of turns of the knob. These reliable and rugged sensors can meet IP66/67 sealing necessities and provide operational life exceeding ten million cycles. A variety of terminations like flying leads and integral connectors are available in many electronic shops.
Pots are continuously improving. With many industries depending on it, it will continue to develop and add features to cater the emergent electronic engineering.