Abstract: Aiming device to position at least one fixing component of the centromedullar type, through an implant.The invention relates to the technical sector of medical sciences.The device according to the invention comprises a viewing type component (1) mounted in a support (5) capable of movement and adjustment in length, rotation, bending and translation, while being likely to recognize the obliquity of the x-ray by viewing it in order to position the viewfinder (1) very precisely level and in line with the part of the nail which should take the fixing component, the said viewfinder (1) being likely to be replaced by a guiding component likely to position the said fixing component.

Abstract: An analog-digital converter supplying a digital output signal in natural or reflected binary code, having an input stage, n consecutive conversion stages comprising two parallel channels of identical structure, in each of which there are two current paths in accordance with the result of a comparison of currents effected in the preceding stage and an output stage to which the switched currents proceed. In the complete converter there are 2.sup.n current paths corresponding to 2.sup.n quantization levels. Conversion is effected by means of a number of stages as small as the number n of bits of the desired digital signal. This converter is simple, fast, asynchronous, has a lower power consumption and its symmetry provides excellent automatic temperature compensation.