Need help for my simple Container Overheat Indicator

Discussion in 'The Projects Forum' started by Lei Reyes, Jan 7, 2015.

  1. Lei Reyes

    Thread Starter New Member

    Jan 7, 2015
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    0
    I have the following setup below for my project Container Overheat Indicator .

    Materials:
    1pc TC4-M1A temperature controller
    1pc 12v 3PDT Relay
    1pc 12v LED Warning Light

    Algorithm:
    1. The Temperature Controller will read and display the temp. of the environment
    2. If the temp reading reaches 70 deg C, the temp controller will turn on the 3PDT relay through its own Relay Output
    3. The 3PDT relay will turn on the 12v LED Warning Light as long as the temp reading is 70 deg C or above
    4. The 3PDT (and the Light), will be turned off by the Temp Controller if the temp reading is already below 70 deg C.

    Questions:
    1. The datasheet does not indicate that the Relay Output of the Temp Controller may be used for DC loads ...
    It only says:
    "Relay Output: 3A/250V AC Capacity"

    However:

    I still tried connecting the 12v 3PDT Relay to the Temp Controller's Relay Output.
    And everything works fine, and the algorithm was followed seamlessly .

    Is it ok to continue doing that ? Is there going to be any problem if I continued doing that?

    2. Do I need to use a flyback diode for the 3PDT relay?

    I uploaded below my setup diagram and the Temp Controller's images and sheets .

    Thanks !
     
  2. MikeML

    AAC Fanatic!

    Oct 2, 2009
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    First, why do think you even need the 3pdt relay?
    Second, why do you think you need two 12Vdc adapters?
     
  3. Lei Reyes

    Thread Starter New Member

    Jan 7, 2015
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    0
    I need a 3PDT relay because I am planning to add two more features but still thinking about it...
    the two 12VDC adapters are used for the power supply of the 3PDT relay and the Light....
     
  4. MikeML

    AAC Fanatic!

    Oct 2, 2009
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    Will they also run on 12Vdc> If so, you could eliminate it.
    A single 12Vdc power supply can run the 3pdt relay and the LED at the same time.
     
  5. Lei Reyes

    Thread Starter New Member

    Jan 7, 2015
    3
    0
    okay, will consider that. thanks !
    so do you think my setup is just ok?
     
  6. MikeML

    AAC Fanatic!

    Oct 2, 2009
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    It'll work...
     
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