Loop Calibrator ( 0 to 20 MA / 4 to 20 MA) Using Mosfet IRF840. Constant Current Source

by rupjit81 in Circuits > Sensors

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Loop Calibrator ( 0 to 20 MA / 4 to 20 MA) Using Mosfet IRF840. Constant Current Source

circuit.jpg

In this instructable I am going to demonstrate loop calibrator. A loop calibrator is a device that generates constant current of 0 to 20 mA used to simulate instrumentation loops in indistry.

Supplies

circuit.jpg
  1. Mosfet IRF840
  2. Suitable heatsink.
  3. 330 ohms 1 watt -- 2 pc
  4. 100 ohms 1 watt -- 1 pc
  5. 10K wirewound potentiometer.
  6. 10K trim Potentiometer.
  7. 1K 1/4 watt resistor
  8. 10K 1/4 watt resistor

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readings2.jpg
breadboard layout.jpg
Constant current source ( 0 to 20 mA) using mosfet IRF840. Operation of mosfet in linear region.

Wire the circuit as shown in circuit. refer attached video for further details.

Connect to required loop and test as current source or simulator.