improvements to devices for controlling and stabilizing the systems in equilibrium, including the type of compensation balance in electromagnetic

摘要

912,617. Valve amplifying circuits. COMMISSARIAT A L'ENERGIE ATOMIQUE. March 10, 1959 [March 10, 1958], No. 8233/59. Class 40 (6). [Also in Groups XXXVI and XL (b)] In a photo-electric servo-system (see Group XL (b)) a frequency selective amplifier comprises two long-tailed pair stages, of which only one input is used, followed by two parallel pentodes as an output stage, the anodes of which supply a frequency dependent negative feed-back to the grid of the first long-tailed pair. The input from the photo-cell pre-amplifier 33 is applied to one grid 36 of double triode 37, the other grid being kept at constant potential, to minimise negative feedback due to the resistor 40. The output from the second, similar, stage is applied to the grids of pentode drivers 42, 43, in the cathode circuit of which is a solenoid 11 acting to keep the light falling on the photo-cell 13 constant. The anode of pentode 42 is connected through a variable low-pass T-section filter 45 to grid 36 to provide negative feed-back. Specification 727,171 is referred to.