Noob question, 10A relay input and outputs?

Discussion in 'General Electronics Chat' started by Tig5, Jun 2, 2018.

  1. Tig5

    Thread Starter New Member

    Mar 28, 2018
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    Hi guys,

    I've been following an online diagram to build an arduino powered beer brewing robot and I'm a bit confused about the terminals on my 10a relays and what should be connected where. The inputs are "IN" "VCC" and "GND", the ouputs are 3 terminals marked in Chinese....
    Should "IN" be the signal from the arduino, VCC be my 5v and GND my general ground, then can I just take my pick in terms of the 3 outputs?
    I'll attach some photos of the relay and the diagram. Any help appreciated!
    MOD: Deleted duplicated photo's

    20180602_231448.jpg 20180602_231416.jpg 20180603_134804.jpg
     
    Last edited by a moderator: Jun 3, 2018
  2. dl324

    AAC Fanatic!

    Mar 30, 2015
    6,958
    1,609
    No. You must use the center terminal. The other you use depends on whether you want the relay to be normally opened or normally closed.

    Can't make any sense from the wiring diagram you posted. Real schematics and wiring diagrams don't look like cartoons with a rats nest for wiring.
     
    -live wire- likes this.
  3. Tig5

    Thread Starter New Member

    Mar 28, 2018
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    Yes, unfortunately I'm having to work with what I have. When the arduino powers up it will require several inputs before the power is directed to the elements. Would this likely mean my relays should default open and switch to closed when the elements are told to begin heating? If so, which output socket should I choose, along with the middle one?
     
  4. Tig5

    Thread Starter New Member

    Mar 28, 2018
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    I've attached the full pdf diagram if that helps...
     
  5. ericgibbs

    Moderator

    Jan 29, 2010
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    hi Tig,
    It is safer to set the relay contacts to Open when the Arduino is switched Off.
    The Arduino relay driving pin should be Set High to energise a relay coil.
    Is this what you are asking.?
    E
     
  6. Tig5

    Thread Starter New Member

    Mar 28, 2018
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    Thanks Eric, that's all a bit above my head to be honest. I think I understand what you mean about having the relay open when the arduino loses power, that makes sense to me.
    I don't know what the arduino relay driving pin is. I found the schematic attached to my last post on instructables.com and have been doing my best to follow it.
     
  7. ericgibbs

    Moderator

    Jan 29, 2010
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    hi,
    In the the that context, when a relay is Open it means there is no path between the relay contacts
    Relay contacts are normally labelled NC [ normally closed] and NO[normally open]
    Normally refers to the relay coil NOT being energised.
    Does this image help.?
    E
     
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  8. Tig5

    Thread Starter New Member

    Mar 28, 2018
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    Thanks for that Eric. So, from my photo above where the label reads "low trigger warning" I'd want to select the top terminal showing the open circuit. That sound right to you?
     
  9. ericgibbs

    Moderator

    Jan 29, 2010
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    hi,
    Look at this image, ask if in doubt.
    E
    ESP1 11-Jun-18 11.22.gif
     
  10. Lyonspride

    Member

    Jan 6, 2014
    127
    19
    It's not going to work if your Arduino board is 3.3v (which most seem to be)............

    I tried using that exact relay module with an ESP8266 and realised very quickly that the least painful (and most compact) way to get it working was to swap the 5v relays for 3.3v relays.

    Also those modules are 0v trigger, so you have to invert your outputs.......
     
  11. Tig5

    Thread Starter New Member

    Mar 28, 2018
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    Thanks for that advice. The trigger for the relays comes straight from a WEMOS D1. Do you happen to have a link for the relays you used?

    Thanks
     
  12. Lyonspride

    Member

    Jan 6, 2014
    127
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    No, sorry I can't remember where I got them, but they were the same brand as fitted to the relay PCB.... I remember buying in bulk, 10 or 20 of them.
     
  13. ericgibbs

    Moderator

    Jan 29, 2010
    5,474
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