GB565108A - Synchroscope - Google Patents

Abstract

565,108. Electric speed - measuring systems. BENDIX AVIATION CORPORATION. April 22, 1943, No. 6516. Convention date, May 23, 1942. [Class 40 (i)] [Also in Group XXXVI] Means for indicating synchronism between two engines, such as aircraft engines, comprises for each engine a generator driving a motor which actuates indicating means, the motors being interconnected by impedance means so that the indicators are oscillated relatively to each other when the speed of one engine changes relatively to the other. The two engines 10, 11 drive shafts 12, 13 carrying permanent magnet rotors 16, 17 of three-phase generators 14, 15. The stator windings 18, 19 are connected with the three-phase stator windings 22, 23 of indicator motors 24, 25. Permanent magnets 28, 29 are driven by the rotors 26, 27 of the motors 24, 25 through connections 30, 31 and are associated with drag cups 32, 33 of non-magnetic metal carried by indicator shafts 34, 35 which are provided with concentric pointers 38, 39. The cups 32, 33 are rotated by eddy currents against the controlling torque of springs 36, 37. Like points of the stator windings 22, 23 are connected by an impedance 42. If the speeds of the engines 10, 11 are equal, the pointers 38, 39 substantially coincide and indicate the speed, since the system maintains its phase and voltage relationships and the rotors 26, 27 run at uniform speed. If one engine speeds up, the system no longer maintains constant phase and voltage relationships and the rotors speed up and slow down once per cycle difference, causing the pointers 38, 39 to oscillate relative to each other. A second impedance may be connected between the same point of the stator winding 22 as the impedance 42 and a second point on the stator winding 23. A third impedance may connect the third point of the winding 23 with a related point of the winding 22. Each impedance may be a resistor or any combination of resistances, capacities and inductances.