GB1304496A - - Google Patents

Abstract

1304496 Measuring angular velocity electrically MOSKOVSKY ZAVOD ELEKTROVAKUUMNYKH PRIBOROV 11 Nov 1971 52382/71 Heading G1N [Also in Divisions H1 and H3] A transducer for measuring angular velocity comprises a tuning fork with its axis on the axis of rotation, made to vibrate at its resonant frequency, so that it acts as an inertia body, and an electro-mechanical pick-up for sensing torsional vibrations of the fork when the assembly is rotated about its axis. The tuning fork 1 Fig. 1, comprises a central stem 8 fixed to the cap 23 of an evacuated glass cylindrical housing 24, having symmetrical magnetic prongs between which is located an exciting coil 3 on a core 4, and an indirectly heated cathode 2. The combination is energized by a battery 31, Fig. 4 with the tuning fork 1 as anode, to cause the prongs to vibrate at their resonant frequency. The stem 8 carries a plate 5, Fig.2 at its upper end, which is oscillated by the stem when the complete assembly is subjected to an angular rotation. Plate 5 and member 9 form a diode with varying conductance, and is energized by battery 34, Fig.4, the A. C. output voltage 11, across load resistor 33 being proportional to the angular velocity. In modifications (a) the plate 5 and cathode 9 are duplicated for mechanical balancing, (b) a fixed grid is located between each anode and cathode, (c) a displaceable grid is used with each electronic unit, attached to the prongs and the stem of the tuning fork, and fixed anode plates are added.