A mechanical scanning device is composed of an oscillating beam onto which a transducer is mounted, part of which is flexible such that the beam will oscillate at a frequency between 8 and 15 Hz when mechanically energized. To sustain oscillation, energy is supplied by means of two electromagnetic coils acting on two permanent magnets mounted on either side of the beam. In order to improve the linear performance of the probe, feedback control was employed. A position sensor along with supporting electronics was designed to provide control signal for the feedback system.
