The line output transformer is a component of a television set / monitor picture tube. It is used to supply the line deflection coil of the Deflection system and at the same time mostly also to generate the for the operation of the picture tube required High voltage from 20 to 30 kV and other voltages required to operate the device. Line transformers work with the Line frequency, for European TV sets with 15.629 kHz. Line transformers in 100 Hz televisions operate at twice the frequency, i.e. at 31.25 kHz. In monitors, the line transformer is operated at different frequencies, which depend on the resolution of the image sent by the computer. Thus, for example, the line frequency of a monitor with a resolution of 1024x768 pixels and a vertical frequency of 85 Hz is around 68.7 kHz.