Abstract: The invention relates to color television receivers.Bursts which are transmitted during the line and field retrace-periods and whose frequencies change from one line to the other between 4.25 MHz (blue, luminance) and 4.40625 MHz (red-luminance) are used to obtain a color identification for each line.To that end a frequency-shift discriminator in which the chrominance subcarrier is switched between two paths, one path being direct and the other comprising a phase shifting circuit, the two parts (9, 10) being thereafter switched to the two inputs of a multiplier (4) whose output signal thus comprises a frequency-dependent DC component. According to the invention, the phase shifting circuit included in one of the paths is constituted by the so-called "cloche" filter (2) which is usually used in all SECAM television sets and which thus fulfills in the circuit according to the invention a special function in addition to its customary functions (FIG. 1).

Abstract: A burst transmission remote control system in which the information about the functions of N transmission channels are indicated by (N + 1) intervals between (N + 2) narrow pulses which are transmitted in repeated bursts, the duration of the intervals having two values defined by the presence or absence of information. The system includes a transmitter having cascaded trigger circuits, and a receiver having a binary/decimal decoder circuit.