Switched-Mode Field Deflection Using Discrete Circuits in Television

Abstract

An experimental switched-mode field time-base suitable for a 16.5 cm picture tube is described here and the circuit is capable of being easily adopted for other TV systems. The main objective of this work is to reduce the total power dissipation in the field-deflection circuitry, which handles currents of the order of a few amperes. As a result of low dissipation in the out put circuit, it would be possible to integrate the circuit including the output stage. The authors have realized, with suitable modifications in circuitry, the discrete version of the field deflection circuit, with power dissipation of 8 watts against the normal dissipation of 14 watts. The basic operation necessary for switched-mode operation is realizing the pulse-width-modulated train and passing it through the field deflection coils with necessary power drive using totem-pole configuration. The various blocks realized are also discussed and the results are summarized.

Indexing Terms:

• Switched-Mode Field Deflection
• Television

Additional information

Notes on contributors

C. Ravichandran

Ravichandran, C. was born in 1949 at Karur, Tamil Nadu. During 1966–71, he studied at Coimbatore Institute of Technology, Coimbatore for his Bachelor Degree in Electronics and Communication Engineering. During 1976–79, he took his postgraduate degree specializing in Communication Systems Engineering. Right from 1972, he is on the Faculty of Electronics and Communication Engineering, College of Engineering, Guindy. Currently, he is working towards his doctoral degree in the area of VHF propagation and digital image processing.

N. Nithiyanandam

Nithiyanandam, N. (Dr.) was born in 1943 at Aruppukottai, Tamil Nadu. During 1960–62, he studied at Coimbatore Institute of Technology, Coimbatore and then at the College of Engineering, Guindy. Madras, graduating in Electronics and Communication Engineering in 1965. From the same College, he took his postgraduate degree in 1972, specializing in Computers. In 1978, the Indian Institute of Technology, Madras awarded him the doctoral degree for his thesis on 3-D Television Systems. Right from 1965, he is on the Faculty of Electronics and Communication Engineering, College of Engineering, Guindy. At present, he is an Assistant Professor. His areas of interest, among other things, include Television Systems and Image Processing.