A battery

{
  "id": "MLC-T-IND-000027",
  "term": "A battery",
  "field": "Industrial and trades",
  "definition": "The low-voltage battery that heats the filaments of vacuum tubes in battery-powered radios and similar equipment, typically at 1.5, 2 or 6 volts and a relatively high current. It forms a set with the B battery, which supplies the higher plate voltage, and the C battery, which supplies the grid bias. The letter names the role of the battery in the circuit, not its physical size, so it is unrelated to the AA cell.",
  "synonyms": [
    "filament battery"
  ],
  "subject": "Industrial electronics",
  "see_also": [
    "B battery"
  ],
  "references": [
    "A battery Definition & Meaning (Merriam-Webster)"
  ],
  "translations": {
    "de": "Heizakkumulator",
    "es": "batería A",
    "fr": "batterie A"
  },
  "url": "https://mlchart.com/terminology/industrial/a-battery/"
}