what does flyback tranformer do?

THE typical flyback or line output (LOPT) consist of two parts:

1. a special transformer which in conjunction with horizontal output transistor/deflection circuits boosts the b+ (120 volt typical for a tv) of low voltage power supplies to 20 to 30 kv(kilovolt) for the crt analog tv.as well as provide various secondary lower voltages for other circuits.


A rectifier turns the high voltages pulses into dc and the crt capacitance smooths it. the hv may be developed from a single winding with many many turns of wire or a lower voltage winding and a diode-capacitor voltage multiplier.

The various secondary voltages power the logic,tuner,video,signal,vertical deflection circuits, and crt filaments.in fact, with many tv designs,the only power not derived from flyback is for the keep-alive circuitry needed to maintain channel memory and provide startup drive to horizontal deflection/high voltage system


2. a voltage divider that provides the focus and schreen supplies. the pots are in this divider network - and these things fail resulting poor focus,uncontrolled brightness,or fluctuating focus and / brightness. a total short could result in failure of other componets like the horizontal output transistor.the focus and schreen are generally the top and bottom knobs,respectively.in some tvs, the focus and schreen divider and/or controls are external to the flyback and susceptible to dust and problems particularly on damp days.

Post edited by: hobbist, at: 2008/05/13 19:04

Post edited by: hobbist, at: 2008/05/13 19:08

Post edited by: hobbist, at: 2008/05/13 19:16

Post edited by: hobbist, at: 2008/05/13 19:17

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excellent information. I hope many members will take advantage from all this experience you are sharing here!

By the way anybody know the P# for flyback for Sony KV2184P

look at recommended resources mat electronic has flybacks on web if not call them.prices seems ok.sony is hard to find.