Device for detecting the activation of a braking system and its use

The detector for a motor vehicle brake actuation has a sensor (5) outside the bore (110) of the brake master cylinder (1). The sensor detects the movement of a pin (3) of the master cylinder piston assembly (10), when the piston passes from the rest position to an active position or vice versa. The pin can be ferro magnetic and can be pivoted to tilt when the piston assembly moves. The sensor can detect a change in the magnetic field.