| 摘要 |
<p>946,218. Automatic position control systems. BAILEY METER CO. Jan. 14, 1960 [Jan. 14, 1959], No. 1440/60. Heading G3R. [Also in Division G1] The position of a valve 34 in a conduit 35 is adjusted in accordance with the difference in pressure across an element 12 in a conduit 14 and the conduit 35 may or may not form part of the conduit 14. A pressure difference across the element 12 is representative of the flow rate in the conduit 14 and is operative to move the core 16 of a transformer 18 whereby an electric signal is supplied to a demodulator 22 which produces a D.C. signal at its output terminals which is recorded on a meter 23 and is also compared with a reference voltage from an element 24, the difference being fed to a controller 26. This error signal is supplied to a magnetic amplifier system 36 by means of which a moving coil element 140 is controlled to move a beam 142 whereby a piston 46 is positioned in accordance with the actuation of a pilot valve 40 by the beam movement. The movement of the piston 46 controls the valve 34 and, by means of a linkage 50 and a cam 52, also moves a core 56 in a transformer 58 whereby a resetting signal is generated which signal is representative of the position of the valve 34 and which is fed to the magnetic amplifier device 36 via an adjustable resistor 94 in opposition to the command signal from the demodulator 26. A resistor 92 is provided for adjustment of the null position of the magnetic amplifier device 36 together with the feedback circuit 120, 122. In another embodiment the valve 34 is operated by an electric servomotor and the control is effected by two magnetic amplifier devices acting in opposition. Specification 425, 507 is referred to.</p> |
