| 摘要 |
1,271,094. Electric motor control systems; electric motors. MINISTERUL INDUSTRIEI CONSTRUCTIILOR DE MASINI. 11 April, 1969 [13 April, 1968], No. 18616/69. Headings H2A and H2J. [Also in Division G3] A ferro-resonant servomotor comprises a rotor 1 (Fig. 1), pole coils 2, 3, 4 and 5 connected to capacitors 6, 7 forming two ferro-resonant circuits, in parallel and connected in series with a circuit formed by saturation (main control) coils 8, 9, 10 and 11 in series with diodes 12 to 15. The series circuit thus formed from the pole coils circuit and saturation coils circuit is connected across a single phase A.C. source U. The servomotor further comprises auxiliary control coils 16, 17, 18, 19 connected in series and to a D.C. control current source U C , the direction of rotation of the rotor depending upon the control current sense. In an alternative embodiment, Fig. 2 (not shown), there are additional main control coils (21 to 23) connected as load in the alternating current supply circuit to the pole coils. In an automatic temperature control system, Fig. 4, the temperature of a boiler 54 is sensed by a thermocouple 55 connected to an indicator which co-operates with photo-diodes 48, 49 in a bridge circuit and bridge unbalance establishes a control current through the auxiliary coils of the servomotor. The bridge is energized from tappings on the pole coils connected via a biphase rectifier 52, 53. The servomotor is coupled to a valve 56 controlling the boiler burner. In a room temperature control system, Fig. 5 (not shown), the motor adjusts a valve (61) connected to a source of steam or hot water in dependence upon the output of a comparator (59) in response to the temperature of the room sensed by a spiral bi-metal transducer (60), whereby to maintain the room temperature constant. |
