SERVODRIVE WITH CONTINUOUS CONTROL

The existing photoelectric telescope guidance systems developed in the SSSR and abroad cannot fully satisfy the demands for weak astronomical object tracking. An analysis of the sensitivity of various instruments in operation shows that the automation of medium sized telescopes with optical guides having 150-200 mm apertures demands a reduction in sensitivity threshold of photoguides by 2 to 3 stellar magnitudes. This may be achieved either by developing more sensitive photomultipliers or by applying the method of accumulation of weak electric signals in photosensors. An experimental study was made of the operation of an FEU-64 photomultiplier under conditions close to those found in automatic guide photosensors using half-disk modulators of light flux. The telescope controlled was an AZT-7 device with a 200 mm aperture and a focal length of 10 m. This article presents the theoretical basis for the photomultiplier operation, the design of the setup, and the results of tests showing that the sensitivity threshold can be lowered to the 2.5-3 level of stellar magnitude by the application of the accumulation method. (Author)
Vozmozhnost Ispolzovaniya Metoda Nakopleniya Slabykh Elektricheskikh Signalov v Fotoelektricheskikh Sledyashchikh Sistemakh Avtomaticheskogo Gidirovaniya Teleskopov. Edited machine trans. of mono. Avtomatizirovanni Elektroprivod. Sledyashchie Sistemy, Upravlenie i Preobrazovatelnye Ustroistva, Moscow, 1965 p80-7.