A device for controlling the positioning of two elements, one of which is stationary while the other is mobile and driven by a geared motor member, the position of the mobile element being controlled by that of a trigger, includes: a circuit; a first stationary Hall effect sensor connected and, together with a magnet borne by the mobile element, providing a negative or zero clearance positioning of the two elements; and a second Hall effect sensor connected to the control circuit and, together with a magnet borne by the mobile element, providing the maximum clearance positioning of the two elements. The magnet is positioned such that its north-south axis is perpendicular to the trajectory of same and the first sensor is disposed in an area where the field vector of the magnet has a component perpendicular to the north-south axis, the sensitive face of the first sensor being parallel thereto.