Measuring transducer e.g. position regulator, for use in system and automation technology of petrochemical industry, has voltage limiting unit, whose feeding voltage is adjustable independent of measured loop current

摘要

The transducer has a connector (6) for attachment at a two-wire current loop (20), and an input for a measured value (MW) that is to be transferred over the loop. A series connection of a regulatable current limiting unit, a voltage limiting unit and a measuring resistor (RM) is provided for measuring a current (i) in the loop. An electrical output of a feeding voltage at another voltage limiting unit is lifted for electrical supply of the transducer. The feeding voltage is adjustable by the latter voltage limiting unit, independent of the measured loop current.