The TV flyback transformer is obsolete in modern television sets and is not used.
In the old cathode ray tube (CRT) television sets the flyback transformer had two functions:
- generate a large and powerful current pulse to drive the horizontal deflection coil in the yoke around the neck of the tube to create a quick horizontal retrace between sweep lines
- using a large secondary autotransformer winding produce a very high voltage (i.e. 15KV to 100KV) rectified by a high voltage diode needed by the anode of the CRT to accelerate the electron beam
