Due to the significant helical magnetic anisotropy, the twisted Fe77.5Si7.5B15 amorphous glass-covered wires present a large Marteucci effect, having a magnitude that can reach up to several hundreds of mV. The idea of our rotary-encoder was to use instead of the magnetizing coil used in the classical Matteucci experiments, the ac field produced by the in-rotation magnetic dipoles of a rotary-encoder rotor. Since the frequency of the Matteucci signal integral (M) is equal with the frequency of the excitation field, we will have that integral (M) = omega xn/2, where omega is angular speed of the rotor and n is the number of magnetic dipoles. As magnetic dipoles we used Nd8Fe86B6 hard magnetic ribbons. The radial ribbons' placement was carefully controlled in order to obtain an alternated distribution of magnetic dipoles. The main advantage of this rotary-encoder consists in the fact that it does not require any power supply or supplimentary electronics, the output signal that comes directly from the ends of the sensitive micro-wire being significant, enough to can be measured by a frequencemeter.