| 摘要 |
<p>402,208. Control of D.C. motors. BAILEY METER CO., 1050, Ivanhoe Road, Cleveland, Ohio, U.S.A.-(Assignees of Ryder, J. D.; 11448, Euclid Avenue, Cleveland, Ohio, U.S.A.) Sept. 2, 1932, No. 24508. Convention date, Sept. 3, 1931. [Class 38 (iii).] A separately excited motor has its armature supplied with direct-current for running, and is stopped by substituting alternating-current for the direct-current. The invention is described in connection with a fluid pressure main. taining system. Upon deviation of the pressure in a pipe 1, a Bourdon tube 3 is actuated to open one or other of switches 24, 25, to interrupt the discharge through a corresponding electron tube 10 or 11, so that pulsating direct-current is applied to the armature of a valve-operating motor 6. The motor is stopped when the switches 24, 25 are operated to allow both tubes 10 and 11 to conduct and supply alternating- current to the motor armature, "plugging" being effected during alternate half-waves. The switches 24, 25, may be hand controlled and arranged to close instead of open, for operation of the motor. In a further arrangement, the motor armature is energised with continuous, instead of pulsating current. The speed of the motor may be varied by arranging the switches 24, 25 to move a choke, the core of which may be shaped, or a graduated resistance, whereby a phase shift between the grids and anodes of the tubes 10, 11, is obtained. The Specification as open to inspection under Sect. 91 comprises arrangements in which the tubes 10, 11, are normally non-conducting. This subject-matter does not appear in the Specification as accepted.</p> |
