An analog data telemetry system for remote monitoring applications: Version I
K. A. McGee, Motoaki Sato · Antarctica A Keystone in a Changing World · 1979
The system described was designed to be used in volcanic gas monitoring experiments and was developed as a result of frustration with the large power consumption of some existing digital data telemetry systems. The heart of the system is a monolithic voltage-to-frequency converter containing an input amplifier used as an op amp, an accurate internal reference generator, a precision oscillator system, and a high current output stage capable of sinking up to 20 mA. The clocking, counting, and driving portion of the system consists of a 4049 hex inverting buffer, a 4081 quad 2-input AND gate, and a 4020 14-stage binary ripple counter. Included are a schematic, parts list, timing diagram, and photograph of the circuit board. (LEW)