Isolation device for pressure transducers installed on telephone line pressure measurement network

摘要

The isolation of the pressure transducers is obtained by switching them out of circuit while they are not actively measuring pressure. The switching is controlled by a bistable relay (108) operated by a pilot circuit (117). The relay operates contacts (101,102; 103,104) which ensure galvanic isolation of the pressure transducer and its connection into circuit to provide data when needed.