Network stabilized for adjusting the automatic brightness in a system for processing of video signals comprising a current limiter of the beams of the image tube -

摘要

P the invention relates to a system for processing of video signals with a comparator for producing an automatic setting brightness, and a current limiter of the beams of the tube image. / p & & p & according to the invention, the limiter automatically 90 is connected to a point 47 of the amplifier 44 for adjust its gain and to limit excessive current application of the beams in a first embodiment, in a second embodiment, the limiter 90 co-operates with the network of adjusting brightness for adjust the level of direct current at the output of the amplifier in the presence of an excessive demand, the response of the comparator 50 is slow with respect to the transient variations of the continuous level at the output of the amplifier, due to the action of the limiter in the first embodiment, but it is not sufficient to allow a compensation of the variations in the long term of the level of direct current, by coupling of the transient voltages of the limiter, 90, to the first embodiment, at a point 49 of the amplifier 44. / p & & p & the invention applies in particular to the color tvs. / p