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Old 12-10-2007, 01:32 AM
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radiotvnut radiotvnut is offline
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Location: Meridian, MS
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Most older TV's still used a big power transformer in the AC supply for most of it's operating voltages, including the CRT filament. Even the older solid state set's (early RCA XL-100 & Zenith Chromacolor II, for example) still used a power transformer in the AC supply. I think the sets with mostly flyback derived voltages came out in the '70's when foreign TV companies were trying to eliminate the heavy and costly power transformer.

There are some later model sets that do not have a bunch of flyback derived voltages. The RCA CTC203 chassis has a switching power supply that provides most voltages for the set. I think there's about 2 or 3 voltages besides the HV generated by the flyback. I think these voltages feed the video output stage and the vertical deflection circuit. In fact, you can pull the flyback out of a CTC203 and still get audio provided the rest of the chassis is OK.
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