산업용 표준 신호들을 4~20mA로 출력하는 새로운 변환기 설계

A novel digital controllable transducer for industry standard signal inputs to 4~20mA was designed. The transducer was composed with digital controll-able universal voltage-to-current converter (VIC) with a current amplifier. The VIC used seven analog switches and six wighted resistor for selecting universal signals. The simulation result shows that thetransducer has good output current characteristics of 4~20mA for the voltage 1~5V，0~5V, -10~+10V, -5~+5V, and 0~20mA. The nonlinearity error is less than 0.1% for the input signals. The transducer has also voltage output of 1~5V when the load resistor is 250Ω.