Improvements relating to servo systems
Реферат: 648,625. Follow-up systems. FERRANTI, Ltd., and TAYLOR, M. K. April 2, 1948, No. 9279. [Class 40 (i)] [Also in Group XL (c)] In a follow-up control-system the angular position of the input shaft controls the frequency of an oscillator 9, feeding a T-attenuator network 14, 15, 16, having its cut-off frequency controlled by the position of a servo-driven output shaft, which varies the mutual coupling in the series arm. Lack of positional correspondence (i.e. attenuator cut-off differs from oscillator frequency) allows an error signal to pass to amplifier 17 feeding one field 20 of the . servo-induction motor 21. 'The other field 22 is fed directly from the oscillator. Since there is substantially 90 degrees lagging leading phase shift between the attenuator input and output voltages just above and below the cutoff frequency, Fig. 3 (not shown), the motor runs in a direction to maintain correspondence. The phase-shift/frequency characteristic is improved by feeding the error signal through a valve amplifier to increase the circuit input impedance, Fig. 4 (not shown). The oscillator frequency may be determined by a similar attenuator network (see Group XL (c)), so that the input and output shafts have the same position/frequency characteristic. Alternatively this characteristic may be obtained by causing the oscillator 85 to be servo driven to follow the cut-off frequency of an attenuator 80 controlled by the input shaft 8. The error voltage is amplified at 81 to operate the twophase servo induction motor 82, and the required frequency taken off at 86, Fig. 7. The attenuator network may alternatively comprise series capacitors and a shunt inductor.
Improvements in or relating to servo-mechanisms
Номер патента: GB884367A. Автор: . Владелец: General Precision Inc. Дата публикации: 1961-12-13.