Hello, I have a miniature resistance thermostat with a M12, 4 poles, male connection that outputs current. Attached to this thermostat will be an extension wire with one side having the 4 wires sticking out and the other with the M12, 4 poles, female connection. Would it be possible to connect this extension cable to an Arduino Uno R3 in order to obtain the data from the thermostat. If so, what other items would I need to purchase to make this project possible and how would I connect them together? Any help or advice is appreciated.
Note: The extension cable transfers 300 Volts and 4 Amps so I'm thinking a voltage converter is needed. I may be wrong since I'm new to Arduino but I believe the model Arduino that I have already contains an analog to digital converter.
First up it's a thermostat probably based on thermistors.
300v @ 4 amp is the rating of the cable, nothing to do with the sensor itself.
Spec sheet has detail on 4-20mA operation but....
Why do you need to go to this type of unit?
One can get a DS18B20 for hobby use, runs on I2C...much simpler and accurate as well.
Your application might shed some light on what you know that we do not.
Are you absolutely certain that you have the 4-20 mA version of the sensor?
If so, you will need to power the sensor using a 10 to 30 V power supply. An Arduino can read the sensor output by measuring the voltage drop across a 250 Ohm resistor connected to ground. When the sensor outputs 4 mA, the voltage across the resistor will be 1.0V and for 20 mA, 5.0V.
For a 5V Arduino, the connections similar to these:
MAKE SURE that you understand the connections to the sensor!
Correct me if I'm wrong but the power supply output I imagine would need to be closely regulated.
Also analog readings in many instances require seval readings and averaging to get anywhere near accurate.
No. The current is accurately controlled by the circuitry of a 4-20 mA sensor, independent of the sensor power supply voltage, as long as it is within the stated range.
The link you posted describes sensors with PT100, PT1000, and 4 to 20mA outputs. Which connection type are you using? What is your power supply voltage?
The reason behind this specific thermostat are due to the extreme conditions of the environment that it will be enclosed. Conditions include high pressure and high temperature that this specific model can withstand.
The specific model I have is the TR33-Z-P2 which falls under the PT100 category. I am still unsure which power supply I should use but have both a 12V and a 24V power supply.
