Fluorescent Lamp Heater Filament Current

Does anyone know the typical current and/or applied voltage through a
fluorescent tube's heater filaments, during startup and continuously through
'rapid-start' types, or know of a good source of this info?
(I'm mainly interested in compact fluoros and small, (F4-T5, F8-T5, G4-T5 ,
G8-T5), standard fluoros.)

Thanks in advance,
.... Steve


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