Depth control system for underwater vehicle

Claim 1

A depth control system for an underwater vehicle comprising: a pressure transducer providing a frequency output proportional to water depth, a first gate, means for periodically opening said first gate, a first binary counter for registering a fixed number of counts, said binary counter being connected through said first gate to the output of said pressure transducer, a second gate receiving opening and closing commands from said first binary counter, first and second storage registers, a crystal oscillator providing a frequency output, Means for connecting said frequency output to said first and second storage registers through said second gate, a reference storage register for storing a digital count representing a preselected water depth, comparator means for comparing the count in said first storage register with the count in said reference storage register and providing an output signal when said counts are unequal, converter means connected to the output of said second storage means for providing an analog output signal proportional to the count stored in said second storage means, and means connected to the outputs of both said comparator means and said converter means for providing an analog depth control signal for controlling said vehicle.