System design for automated airborne data acquisition

A system control unit, using discrete TTL (transistor-transistor logic) components, was designed and built in 1983 by the US Department of Defense. This control unit was needed to automate the process of acquiring and recording fuel tank temperature data during extended flight periods. The program's goal was to determine the coldest temperature jet fuel would experience during flight. The authors compare this digital circuit design with a proposed microprocessor-based design intended to replace the original digital system controller. The microprocessor design is shown to decrease the size and power consumption, while increasing the system's reliability. Further, this new design is configured to use existing input/output devices.<>