A phototransistor is an electronic switching and current amplification component that relies on exposure to light to operate, much like how normal transistors rely on electricity to operate. When light falls on the junction of a phototransistor, reverse current flows in proportion to the luminance of the light. This makes phototransistors excellent at detecting light pulses and converting them into digital electrical signals. Unlike normal transistors, they are operated by light rather than electric current, and provides a large amount of utility for a low cost.
Field effect transistors (FETs) are used to amplify weak signals, mostly wireless signals. This is useful for aircraft, that often operate dozens if not hundreds of miles away from the signal’s source. A field effect transistor is a type of transistor that alters the electrical behavior of a device using an electric field effect to control the electrical conductivity of a channel. FETs are classified into JFET (Junction Field Effect Transistor) and MOSFET( Metal Oxide Semiconductor Field Effect Transistor). Both are mainly used in integrated circuits, and are similar in operating principles, but different in composition.
Multiple instruments inside an aircraft’s cockpit are dependent on AC transducers. Transducers include synchros, resolvers, and linear/rotary variable differential transformers (LVDTs/RVDTs) and are used in numerous applications including navigation reference units, automatic direction finders, distance measurement equipment, and landing gear position and control. Synchros have been used in both commercial and military purposes; they are the transducer of choice when reliability is important and environment conditions are unforgiving.
