Electronics Fundamentals Finals - Servomechanisms

Electronics Fundamentals Finals - Servomechanisms

• Servomechanism is an electric control system for automatic mechanisms.
• It generates motion or force using low-energy input signals.
• Objectives include defining and describing the servomechanism principle and enumerating its aircraft applications.

Open and Closed Systems

• Open loop systems: controls are set to the desired setting.
• Closed loop/Servomechanism systems: include feedback or follow-up from the controlled unit.

Differential Transducer

• An electric device which converts the differing position of flight control surfaces into a variable electric output signal.
• This signal can be processed by the controller.

Linear Variable Differential Transducer (LVDT)

• Converts linear motion into an electrical signal.

Rotary Variable Differential Transducer

• Measures angular motion.
• Function by the rotor's motion within an electromagnetic stator field.

Synchro Systems

• Electric systems for transmitting information between points.
• Used in remote position indicators (landing gear, autopilot systems, radar).
• Types of synchro systems:
  • Autosyn
  • Selsyn
  • Magnesyn

DC Selsyn Systems

• Consists of a transmitter, indicator, and connecting wires.
• Uses components like a resistance winding, brushes, a rotor shaft, contact arm, and a permanent magnet.

AC Synchro Systems

• AC Magnesyn uses permanent magnet motors.
• AC Autosyn uses electromagnets, differing from permanent magnets.

Modern AC Synchro Systems

• Torque Synchro Systems: for transmitting position information.
• Control Synchro Systems: for precise systems requiring feedback and control.
• Differential Synchro Systems: for applications needing relative position between objects.
• Resolver: for sensing and tracking angular positions of devices.

Inductance Transmitters

• Used in older instruments, acceleration sensors, and air data computers.
• Uses inductance windings similar to synchros, but the shape and spatial location are like the letter "E".

Capacitance Transmitters

• Used on aircraft to transmit fuel condition.
• Often used in transport aircraft fuel quantity systems.
• Depends on area of plates, distance between them, and dielectric constant of separating material.