Abstract: This invention concerns television scanning circuits.It involves a scanning startup circuit comprising a capacitor, and means of gradual charging or discharging, to produce a priority voltage transmitted at startup to replace a control voltage, regulating a chopped power supply circuit which is to be started up progressively. At the end of a certain period of time, the regulation control voltage takes over from the original voltage which, at startup, is at a level such that it prevents over-consumption of current in power components. The circuit is also protected against voltage surges, being halted and restarted automatically and gradually in the event of such a surge.

Abstract: This invention concerns an integrated interface circuit between a television receiver and its peritelevision connector, to allow the connection of an external source such as a magnetoscope. Said circuit comprises a video interface stage (E.sub.V), an audio interface stage (E.sub.A), and a switching stage (E.sub.C), which uses logic signals at its inputs (13, 12, 11) to switch, or not switch, on the one hand a selector switch (I1) in the video stage, and on the other hand two selector switches (I2, I3) in the audio stage.

Abstract: Devices for displaying a label on a visualization screen. The information display inserted into a background image is provided by a character-generating circuit. The stability of the label requires synchronization of the vertical scanning of the image and of the label. This synchronization is obtained by measuring the current which flows through the deflector of the cathoscope tube: the information acquired, amplified, is applied to a threshold detector which controls the display circuit. The beginning and the end of synchronization are regulated by two reference voltages. The invention applies to the display of information on television receiver or visualization console screens.

Abstract: The invention relates to a circuit for decoding chrominance signals from the composite videofrequency signal in the Secam color television system. In order to direct each chrominance signal to the corresponding channel, it is proposed in accordance with the invention to extract the demodulated signals at the beginning of each line and to treat them in the first place by a controlled circuit which equalizes their d.c. voltages, in the second place by a color identification circuit which synchronizes the commutator with the television transmitter and in the third place by a "keeper" circuit for identifying the Secam process which inhibits the chrominance circuit if the transmission is by another process or parasitized. Application to television receivers using the Secam system.

Abstract: An elastic surface wave filter including on the surface of a plate, an emitting transducer, a surface wave coupler, and means for receiving the waves radiated by the coupler. The means for receiving includes two transducers each having two terminals with one terminal of each being in common with one terminal of the other. The common terminal serves as a phase reference and the voltages induced at the remaining terminals are in phase opposition to one another in the transmission band of the filter.