Matrix circuit for SECAM coder - has three emitter coupled transistors with frequency dependent negative feedback on two input circuits for video pre=emphasis

摘要

The SECAM coder converts three chrominance signals into a luminance and two colour difference signals. It consists of three emitter coupled transistor stages, to whose bases the chrominance signals are applied, with the colour difference signals collected from their collectors. The luminance signal is collected from the common node of the three emitter resistors. A video preemphasis circuit is provided for each colour difference signal. The input circuits of the transistor stages for the R and B chrominance signals have a frequency dependent negative feedback circuit.