| 摘要 |
866,175. Control of A.C. motors. SOC. TECHNIQUE POUR L'INDUSTRIE NOUVELLE S.A. STIN. Sept. 4, 1959 [Sept. 5, 1958], No. 30207/59. Class 38 (3). [Also in Group XXX] Relates to a remote control system for a reversible two-phase motor M regulating the position of railway switch points, wherein the motor is connected to the controller through four leads L1-L4. When the motor is at rest in the position shown, half-wave supervisory current passes from supply terminal S to neutral N through motor windings Ml, M2, relay coil H, and rectifier V. The rectifier is shunted by choke B4, one winding section of relay B3, and indicating relay NR, so that alternate halfwaves pass through these elements. Energization of relay NR indicates the continuity of all the components through which the supervisory current passes, including the motor windings and the four leads L1-L4. When the points are to be changed-over, relays E, F and G are energized, the supervisory current is cut-off, and relay H is de-energized to isolate indicating relays RR, NR from lead L2. Current passes from terminal P1 through motor winding M2 and winding Y of auto-transformer B5 to neutral, phase-displaced current passing from terminal P2 through motor winding M1 and transformer winding X, whereby the motor is energized to move the driven element T away from its end-position. Relay B3 is connected across leads L2, L3, in series with choke B4 and in shunt with rectifier V, but, since the relay is polarized, it does not respond at this stage. When contact N engages contact N2, the leads L2-L3 are connected directly until contact R engages contact R2. The relay B3 is now energized in the reverse direction and becomes effective to stop the motor. Since contacts N, R carry only the supervisory current, they may be of light construction and totally enclosed in a vacuum or protective gas. |
