Demodulator circuit for SECAM colour TV signals - has comb filters for (R-Y) and (B-Y) signals, with delay line and adder for each signal

摘要

The circuit has a demodulator with an input for colour TV carrier signals, controlled by control pulses, the frequency of which is equal to half the line frequency in order to switch colour difference signals (R-Y, B-Y). A comb filter is provided for the (R-Y) signal, the input of which is connected to the demodulator (R-Y) output. A delay line delays signals by one line period and has an adder which applies to the (R-Y) output the sum of the delayed and non-delayed signal. A comb filter for the (B-Y) signal is similarly connected and has a similar delay line and adder.