Isolated 4-20 mA Current-Loop System in the Experiment of Coal Pyrolysis in H-plasma Producing Acety

The purpose of this paper is to demonstrate a systematic approach to design high performance signal conditioning circuits, and to show how to implement the 4-20 mA analog current-loop transmitter and receiver circuits by using isolation amplifier.The basic principle and typical applicable circuits of the 4-20 mA current loop isolation chip Tll00N, the current-limiting circuit and filter circuit are presented.And the experimental testing data of the circuits are analyzed.