This circuit provide current loop transmitter for temperature sensor. Current loop interface has been widely used in industrial environment because it’s robustness. This is the figure of the circuit.
The temperature measurement is done by LM35 temperature sensor chip. You can use general silicone diode such as 1N4001. The current controller function is done by LM317 current/voltage regulator. This circuit will draw a consistent current proportional to the temperature being measured, regardless the supply voltage variation caused by noise or long wire’s temperature-dependent resistance variation.
The temperature measurement is done by LM35 temperature sensor chip. You can use general silicone diode such as 1N4001. The current controller function is done by LM317 current/voltage regulator. This circuit will draw a consistent current proportional to the temperature being measured, regardless the supply voltage variation caused by noise or long wire’s temperature-dependent resistance variation.
