noun
the battery used to heat the filaments of a vacuum tube
• Hypernyms: ↑battery, ↑electric battery
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\\ˈāˌ-\ nounUsage: usually capitalized A
: a battery used to heat the filaments or cathode heaters of electron tubes — called also filament battery; compare b battery
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Electronics.
an electric battery for heating the filament or cathode heater of an electron tube. Cf. B battery, C battery.
[1920-25]
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A battery,
a low-voltage battery connected to both ends of the filament in an electron tube, for heating the filament.
Useful english dictionary. 2012.