Dynamic Behavior of AGC-AFC Compound System for TV Receivers

This report discusses basic design theory for horizontal deflection AFC circuits. This theory was developed from the author´s past study, and constitutes the third report of the engineering trilogy [1] [2] on this complex circuit. In the second report of the trilogy [2], the pull-in effect was analyzed by transforming the horizontal AFC circuit into a piece-wise-linear second-order system and making a phase plane analysis of the latter system. However, since subsequent study revealed that Richman´s approach [3] in his analysis of color synchronization APC circuits is equally applicable to the analysis of horizontal AFC circuits, the author used Richman´s methods to develop simple but practical design formulas for the latter circuits. In addition, it was found that the new theory could be expanded to clarify certain problems concerning pull-in time and interaction with the AGC loop, which were resistant to the former theory. Although there are still many points concerning the mutual effects of AGC and AFC loops that are yet to be clarified, a promising approach to the problem will be described herein.