The device is intended to control the elevation of the light beam of a head light of a passenger car. The driver can control the elevation of the light beam by rotating a potentiometer on the dashboard (the setting potentiometer). The device adapts the elevation of the light beam by activating the control motor. The elevation of the head light is fed back to the device by a second potentiometer (the feedback potentiometer). This feedback potentiometer is mechanically coupled to the motor.