GB950955A - Electrical arrangements for automatically controlling the speeds of rotating members - Google Patents

Abstract

950, 955. Automatic speed control. LICENTIA PATENT-VERWALTUNGS-G. m. b. H. June 15, 1960 [ June 15, 1959; Sept. 18, 1959], No.21011/60. Heading G3R A train of pulses whose frequency represents the speed of a shaft to be controlled is compared at point 11 with a train representing the speed of a pilot shaft, the differential pulses being applied to a counter 12 which affords a measure of the angular displacement between the shafts. A digitalanalogue converter 14 provides a voltage representing the angular displacement, and this voltage is added at point 2 to another voltage which is proportional to the pilot speed, the resultant voltage being supplied to a speed regulator 3 for correcting the velocity of the controlled shaft. The speed regulator may comprise an internal feed-back loop circuit. In the event of large angular deviations,the output of the converter 14 is restricted, the excess pulses being stored in the counter 12 so that correction may be made at a lower rate. In another arrangement, the output voltage of the converter 14 is integrated to provide an additional corrective voltage, Fig. 2 (not shown). The pulse train representing the pilot speed may be derived from a pulse generator associated with the pilot shaft and connected to a counter and a frequency multiplier. The output of the multiplier is supplied to a frequency divider which is adjustable in fine stages to provide a pulse train corresponding to a desired speed ratio, and is also applied to a fixed frequency divider for feed-back to the input of the counter, Fig. 3 (not shown). In a modification, the train of reference pulses has a constant frequency and is derived from a quartz crystal.