I am new to this, I have 3 120 volt 13 amp electric motors I need to turn on and off by temperature settings
Exp. When a tank cools down to a set temp I need the motor to come on and when it reached a set temp for the motor to turn off
Any help is appreciated
We will help you with your code.
Have you written any?
What hardware experience do you have?
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use op-to coupled relays to switch motors on/off
https://arduino-info.wikispaces.com/RelayIsolation
what temperture sensors are you planning to use?
Hi,
DISCLAIMER: Mentioned stuff from my own shop...
Large motors like that it's probably best to use opto-isolated Solid State Relays. (Example)
At 13 Amps you should mount these on a heat sink or attach them to some sheet metal box etc.
I have used THESE
I would mount these close to the motor or existing switch, in a metal box. Run twisted pair wire from the isolated input control connections back to an Arduino digital output. You may be able to run CAT5 cable to the motor area from the Arduino.
Best to keep the Arduino separated from the high-power stuff.
Suggest you see THIS Page
What has your research turned up?
If you have not researched it yet, consider reading up on it.
http://arduino-info.wikispaces.com/ArduinoPower
Temperature sensors, relays for the motors, and if-statements to turn on/off the motors if the temperature is above/below the threshold.
Analog temperature sensors such as the LM34/LM35 are easy to use. You'll just have to figure-out the scaling (ratio) between from the ADC reading to temperature. The LM34/35 datasheet shows volts/degree, and although the Arduino's ADC reads voltage, it doesn't read in "volts" That's OK because you don't want volts you want degrees.
Start with the Analog Read Serial Example, then Read Analog Voltage Example. Then you can modify it to read temperature.
You can get [u]Solid State Relays[/u] that can be directly driven by the 5V low-current Arduino output., and the screw-terminal type is easy to wire-up and mount. A regular-old electromechanical relay will require a driver circuit, but you can get a relay-board with a driver built-in.
You can test the relays with the Blink example. You'll probably want to decrease the "blink" speed with motors, and for further testing you can modify the program to "blink" the 3 motors in sequence, etc.
Then, it's just a matter of putting it all together with some if-statements.
DVDdoug:
Analog temperature sensors such as the LM34/LM35 are easy to use.
...newbies have big problems with them.
Not working, wrong temp and not stable because of the code, etc.
Better use a factory calibrated waterproof digital DS18B20 sensor.
Leo..
Hi,
factory calibrated waterproof digital DS18B20 sensor
Agree.. and they are good for multiple sensors with easier wiring and longer cables.
How-To HERE:
This is great info and I am looking at the ds18b20 for the temp.
Do you have experience with high voltage and current?
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Yes I have experience with the high voltage but not the arduino