|
Regarding the 1B3 filament winding, the number of turns required to get the 1.4V needed by the tube filament depends on the design of the other windings of the flyback transformer. A specification called the Turns Per Volt Ratio is determined by the ratio of the number of turns in the primary winding to the AC voltage applied across the primary winding. Voltages induced in each secondary will be determined as a function of the Turns Per Volt Ratio. A transformer with a TPV of less than 1 is not uncommon, so a 1/2 turn secondary winding producing 1.4V is not unusual. Many color sets had low-ratio flyback transformers and produced 3.3V for the HV rectifier tube filament (3A3, 3B2, 3AT2, etc.) with single or 1-1/2 turn secondaries while deriving focus rectifier filament voltage for a 1X2, 1V2 or 2AV2 from a 1/2 or 3/4 turn winding.
|