Watch receiver

{
  "id": "MLC-T-IND-006528",
  "term": "Watch receiver",
  "field": "Industrial and trades",
  "definition": "A type of early earphone or transducer used in telephony and radio communication systems, named for its resemblance to a pocket watch. It consists of a permanent magnet, an electromagnet coil, and a thin iron diaphragm that vibrates in response to audio-frequency electrical currents to produce sound. These devices were characterized by their high impedance, often in the range of 1000 to 2000 ohms, which made them sensitive to the weak signals available from early electronic equipment.",
  "subject": "Electrical engineering",
  "translations": {
    "de": "Taschentelefon",
    "es": "receptor de reloj",
    "fr": "récepteur de montre"
  },
  "url": "https://mlchart.com/terminology/industrial/watch-receiver/"
}