Arrangement of electronic parts for an anti-lock braking system for a vehicle

A circuit arrangement for an anti-lock braking system for a motor vehicle, comprising:

• electronic wheel sensors which monitor rotation behavior of wheels of the motor vehicle during braking;
• a control unit which evaluates signals from the wheel sensors and which acts on the wheels to prevent locking thereof;
• a first clearance sensor, which is fitted close to or on a vehicle floor of the motor vehicle and which is directed toward a road surface, and which has a radiation transmitter and a radiation receiver;
• a memory unit which briefly stores sensor signals received from the first clearance sensor;
• an evaluation unit, by means of which the stored sensor signals of the first clearance sensor are checked for changes which indicate a movement of the motor vehicle;
• a second clearance sensor fitted close to or on the vehicle floor, and directed toward the road surface, such that the second clearance sensor receives radiation signals reflected from the road surface at a point at which the first clearance sensor has previously received the reflected radiation signals for a straight-ahead movement of the motor vehicle;
• at least one adjustable delay unit connected to the evaluation unit;
• the sensor signal, which is received from the first clearance sensor and stored, being compared by the evaluation unit, after an adjusted delay time, with a sensor signal received from the second clearance sensor, and, if the compared sensor signals correspond, a control signal being transmitted to the control unit, which control signal indicates that the motor vehicle is skidding.