| 摘要 |
787,933. Measuring speed. COMITE ELECTROTECHNIQUE BELGE. Nov. 2,1955 [June 11, 1954], No. 31372/55. Class 40 (1). In order to measure the speed of a moving body 4, the latter is mechanically connected to the movable part of a capacitive transducer 2, the capacitance of which varies linearly with displacement of the moving body, in series with a resistor 5 across a D.C. source. The voltage across the resistor corresponds to the instantaneous value of the speed and is amplified at 7 and indicated on a cathode-ray tube 8 and voltmeter 9. Construction of transducers. In one arrangement, Figs. 2 and 3 (not shown) the transducer comprises two sets of diametrically opposed quadrant shaped fixed plates and a corresponding set of movable plates on a rotary shaft. In a modification, Figs. 7 and 8 (not shown), the same arrangement is provided with the further sets of fixed plates connected to ground and acting as a guard electrode. As shown in Fig. 4, the plates may be of cylindrical shape where the movement being investigated is rectilinear. In another form, Figs. 9 and 10, for rotary motion in which the stator consists of a pair of oppositely disposed quadrant-shaped capacitor plates 6 separated by a similar pair of guard plates 18 and the rotor comprises a pair of quadrant-shaped plates, all the plates are furnished with flangelike projections 19, 21, 22. |
