Amplifier and Driver Circuits for Thin Film Memories with 15 Nanoseconds Read Cycle Time
Amplifier and driver circuit design principles for an experimental 4608-bit nondestructive thin film memory with 13.5-nsec read and 60-nsec write cycle times are given. The bit noise problems inherent in the common bit sense line concept are solved by using tunnel diodes in a nonlinear balancing circuit. A further improvement of the signal-to-noise ratio is achieved by employing a noise resistant sense amplifier with nonlinear negative feedback. The word driver described is capable of delivering 700 ma pulse amplitude at 50 mc repetition rate at a pulse width of 7 nsec.
Symbolic Design Techniques Applied to a Generalized Computer
1. Introduction. The purpose of this article is to present a revised version of an early paper by the author on a register transfer, logic design language and its application to the design of early microprogrammable computer. This paper [1] as an invited paper at an IRE was presented originally at an IEEE meeting held at the Moore School of the University of Pennsylvania, early in 1957. It is being published here in the open literature for the first time in order to present to a wider audience this approach to computer design in its original form.
Turbine blade temperature calculation and life estimation - a sensitivity analysis
Abstract The overall operating cost of the modern gas turbines is greatly influenced by the durability of hot section components operating at high temperatures. In turbine operating conditions, some defects may occur which can decrease hot section life. In the present paper, methods used for calculating blade temperature and life are demonstrated and validated. Using these methods, a set of sensitivity analyses on the parameters affecting temperature and life of a high pressure, high temperature turbine first stage blade is carried out. Investigated uncertainties are: (1) blade coating thickness, (2) coolant inlet pressure and temperature (as a result of secondary air system), and (3) gas turbine load variation. Results show that increasing thermal barrier coating thickness by 3 times, leads to rise in the blade life by 9 times. In addition, considering inlet cooling temperature and pressure, deviation in temperature has greater effect on blade life. One of the interesting points that can be realized from the results is that 300 hours operation at 70% load can be equal to one hour operation at base load.