Transducer Applications

• Electromagnetic:
  • Antenna – converts propagating electromagnetic waves to and from conducted electrical signals
  • Magnetic cartridge – converts relative physical motion to and from electrical signals
  • Tape head, Disk read-and-write head - converts magnetic fields on a magnetic medium to and from electrical signals
  • Hall effect sensor – converts a magnetic field level into an electrical signal

• Electrochemical:
  • pH probes
  • Electro-galvanic fuel cell
  • Hydrogen sensor
• Electromechanical (electromechanical output devices are generically called actuators):
  • Electroactive polymers
  • Galvanometer
  • Microelectromechanical systems
  • Rotary motor, linear motor
  • Vibration powered generator
  • Potentiometer when used for measuring position
  • Linear variable differential transformer or Rotary variable differential transformer
  • Load cell – converts force to mV/V electrical signal using strain gauge
  • Accelerometer
  • Strain gauge
  • String potentiometer
  • Air flow sensor
  • Tactile sensor

• Electroacoustic:
  • Loudspeaker, earphone – converts electrical signals into sound (amplified signal → magnetic field → motion → air pressure)
  • Microphone – converts sound into an electrical signal (air pressure → motion of conductor/coil → magnetic field → electrical signal)
  • Pickup (music technology) – converts motion of metal strings into an electrical signal (magnetism → electrical signal)
  • Tactile transducer – converts electrical signal into vibration ( electrical signal → vibration)
  • Piezoelectric crystal – converts deformations of solid-state crystals (vibrations) to and from electrical signals
  • Geophone – converts a ground movement (displacement) into voltage (vibrations → motion of conductor/coil → magnetic field → signal)
  • Gramophone pickup – (air pressure → motion → magnetic field → electrical signal)
  • Hydrophone – converts changes in water pressure into an electrical signal
  • Sonar transponder (water pressure → motion of conductor/coil → magnetic field → electrical signal)
  • Ultrasonic transceiver, transmitting ultrasound (transduced from electricity) as well as receiving it after sound reflection from target objects, availing for imaging of those objects.

• Electro-optical (Photoelectric):
  • Fluorescent lamp – converts electrical power into incoherent light
  • Incandescent lamp – converts electrical power into incoherent light
  • Light-Emitting Diode – converts electrical power into incoherent light
  • Laser Diode – converts electrical power into coherent light
  • Photodiode, photoresistor, phototransistor, photomultiplier – converts changing light levels into electrical signals
  • Photodetector or photoresistor or light dependent resistor (LDR) – converts changes in light levels into changes in electrical resistance
  • Cathode ray tube (CRT) – converts electrical signals into visual signals

• Electrostatic:
  • Electrometer

• Thermoelectric:
  • Resistance temperature detector (RTD) - converts temperature into an electrical resistance signal
  • Thermocouple - converts relative temperatures of metallic junctions to electrical voltage
  • Peltier cooler
  • Thermistor (includes PTC resistor and NTC resistor)

• Radioacoustic:
  • Geiger–Müller tube – converts incident ionizing radiation to an electrical impulse signal
  • Receiver (radio)
  • transmitter-propagates electromagnetic transmissions to sound