Abstract: A brake control system has a controller (52, 53, 54) including hysteresis. To prevent over-shoot of control operation if a comparison between actual braking pressure (P.sub.act) and commanded pressure (P.sub.com) is applied to control valves which, for example, operate pneumatically, so that the brakes will not instantaneously respond, a difference pressure threshold (.DELTA.P.sub.G) is determined and, when the difference pressure level is passed by the difference pressure signal, the valves are controlled to operate in pulse operation, in which each pressure pulse (T.sub.E) is followed by a quieting or pressure-OFF time (T.sub.BER). The pulse sequence and the timing of pulses and pulse gaps is controllable in accordance with pressure levels, operating parameters, pressure difference levels and the like.

Abstract: A short-circuit protected mains supply unit, especially for the screen-text component of a television receiver. A conventionally controlled unit is expanded in accordance with the invention with only a few components (T1 and T2) in such a way that it can be turned on electronically and its output is protected against short circuits.