Abstract: An anti-block control system has four identically designed control channels. Safety circuits (8, 8') are also provided for monitoring the system, as are devices for testing the operability of the system. In this test, performed while the vehicle is stopped or when it is started, a test signal is fed into the channels and the effects of this signal are compared, in pairs, at locations of the controller corresponding to one another. A signal train is formed when the comparison is made. In accordance with the invention, two safety circuits (8, 8') are provided, each associated with a pair of channels, and the signals from all the channels are supplied, in pairs, to the safety circuits. The safety circuits include timing elements. During a test cycle, the signal trains in the two channel pairs generated by using the test signal are compared with one another by use of two comparator circuits (23, 23'), and in the case of non-agreement, a warning or switching signal (18, 18', 31) is generated.

Abstract: An anti-skid brake system for vehicles is proposed in which various transducers for detecting operating condition parameters of the vehicle are provided, which cooperate with an evaluation circuit in such a manner that control signals are formed on the basis of the transducer signals for influencing the brake pressure at predetermined operating conditions. Circuitry are additionally provided which store the operating condition parameters, such as vehicle speed and deceleration, braking path and the like, during the braking event under the predetermined operating conditions; and to control marking of the road surface during these braking events.

Abstract: An anti-skid system for motor vehicles in which the wheel speed is detected by individual transducers and in which two or more transducer signals are alternately periodically connected to a single processing channel for controlling the braking pressure. In order to improve the performance on an inhomogeneous road surface, the connection rhythm of transducers is changed upon the occurrence of a tendency of one of the wheels to lock. According to the invention, the two wheels associated with a single processing channel are the two wheels on the same side of the vehicle, especially the rear wheels of dual rear axle utility vehicles.