| 摘要 |
736,234. Speed indicators. POWER JETS (RESEARCH & DEVELOPMENT), Ltd. Dec. 23, 1953 [Dec. 31, 1952], No. 33095/52. Class 106 (3). Means for indicating any deviation of the speed of a rotor from a prescribed value which can be varied in accordance with an independent variable comprises, in combination, a rotary member driven at a speed proportional to that of the rotor, a source of accurately determined basic reference speed or frequency, a second source of speed or frequency variable at will in accordance with the independent variable, means for correcting the basic reference quantity by combining therewith the speed or frequency of the second source and means responsive to any deviation of the speed of the rotary member from a speed or frequency corresponding to the corrected basic quantity. The invention as described is applied to a gas turbine plant in which it is desired to maintain the speed of turbine 7 in a particular relationship with the temperature at the inlet 59 of the compressor 1. A speedometer 9 and stroboscopic disc 10 are driven at the speed of the turbine. The frequency of the flashes of the device 13 is controlled, as described later, to correspond to the temperature so that the disc 10 appears to be stationary if the desired relationhip between the speed and temperature pertains. The output from a basic frequency reference source 27 is fed through a push-pull amplifier and a phase changer comprising two identical balanced circuits to the insulated quadrants 44, 45, 46, 47 of a frequency changer the conducting disc 48 of which is carried by a shaft 49 driven by a motor 50 the speed of which is controlled by a potentiometer 53 graduated for adjustment in accordance with the reading on a temperature-measuring ammeter 56. The output from the frequency changer is taken from the disc 48 to the grid 61 of a triode of a cathode following circuit across the output of which is connected the flashing device 13. In operation the potentiometer 53 is adjusted in accordance with the temperature indicated on ammeter 56 to determine the frequency of the flashes of the device 13 and the speed of the turbine is adjusted, if necessary, by the fuel regulator 5 until at the appropriate speed the disc 10 appears to be stationary. |
