Question

An operator in a petrochemical plant would like to have a set of indicator lights that point out when the furnace temperature reaches certain levels. The operator wants a GREEN light to indicate a temperature (T1) of 150 °C up to 249 °C, YELLOW light to indicate 250 oC to 499 °C, and RED light to indicate above 500 °C. The (2-20mA) temperature sensing instrument outputs 2mA when the temperature is 50 °C, and 20mA when the temperature is 500 °C. Using the network shown in Fig.1, design a circuit that will satisfy the operator's requirements 15V 2-201nA 5102 Green 15V Yellow 15V Red ได้ 15V Rs R, R- R. Fig.1: Proposed Design Circuit Schematics

Answer 1

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opame can be S SET or YOOFF 10. 13 votaboue ohichYELLO LED case 3 , :Curent sen*or value S00 Poi VO l RED LEOwen ohin tempexaus is geot than atie voltage n r10. 179volts SV Lj Vol- I- 0.3386

For ellow LED 10.179-Volta terminal ISV LED 3 R3+2y 0.6286 6236 0.3214 6386 -6386 -0-686 For Red LED to glo 15V R5 25+2c 15 RC R5 +R6 O 32