current controlled AC relay

Discussion in 'General Electronics Chat' started by bucs_fan069, Jun 25, 2010.

  1. bucs_fan069

    Thread Starter New Member

    Jun 25, 2010
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    OK, I have been using the expertise on this forum to try and determine exactly what I need for this project. I would like to keep it as simple as possible and I am hoping that just a relay will fit the bill. What I need is a "component" that can sense a current draw on a 120 AC wire (lets say a fan turning on). and when it senses this it makes a contact on another AC circuit. SO basically when someone turns on a fan the lamp next to it will automatigically turn on as well without any other intervention by the user. and when the fan is turned off the light will also go out. Anyone know of a relay that can accomplish this task?
     
  2. mcgyvr

    AAC Fanatic!

    Oct 15, 2009
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    Based on the information provided (or lack of additional information) No relay is necessary... you would simple wire the 2 devices in parallel. Just like plugging in both devices to the same outlet circuit.
     
  3. bucs_fan069

    Thread Starter New Member

    Jun 25, 2010
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    That actually would not work as I would like for the light to only be "ON" when the fan is drawing current (on). The fan will always have power applied to it and when it draws current, that would "flip the switch" to make the light receive power.
     
  4. kingdano

    Member

    Apr 14, 2010
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    well they make those proximity outlet testers that sense the presence of 120VAC and light-up an indicator for you.

    you should look into those, i forget what they are called.

    check out home depot's website or something - outlet testers.

    you could maybe copy that, or just tap off of the led's "enable" line.

    just a thought
     
  5. mcgyvr

    AAC Fanatic!

    Oct 15, 2009
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    So the fan has it's own switch? So simply wire both devices to the fan switch (if rated for the current).
    Or leave the fan switch on all the time and wire in another switch before it so it will turn on both devices. Still no relay needed. I'd just go to the hardware store and pick up a wall switch, box and coverplate and be done.
     
  6. mcgyvr

    AAC Fanatic!

    Oct 15, 2009
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    Don't make it harder than it is.
     
  7. bucs_fan069

    Thread Starter New Member

    Jun 25, 2010
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    You are absolutely right as I could wire from the fan switch. Although I might have left out a critical component in the description. The fan is one of those fans that has a built in temp sensor so the fan will turn on automatically throughout the day when it senses the temp go above a set point. I really didn't want to get into running a bunch of control wires to the fan, I was hoping for a current sensing (similar to an amp clamp) device that I could run the power wire thru a couple of turns and have that trigger a relay to allow 120 power to another device. I also have a couple other ideas that such a relay would come in handy for.
     
  8. mcgyvr

    AAC Fanatic!

    Oct 15, 2009
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    NOW we are getting the missing details. Anything else?
     
  9. bucs_fan069

    Thread Starter New Member

    Jun 25, 2010
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    Not really, I am basically looking for a device that can sense AC current (amp clamp style) and that will turn on 120 AC to another device. I was hoping it would be as simple as a current triggered relay...but I am not sure if such a device exists...
     
  10. eblc1388

    Senior Member

    Nov 28, 2008
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    They do.

    Try using "AC POWER SLAVE" as search term in Google.
     
  11. hspalm

    Active Member

    Feb 17, 2010
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    Can you make a simple halleffect circuit? It should not be that complicated. You should also be able to mod one of this electrician pens/screwdrivers with a lightbulb on the back wich lights up as the screwdriver makes contact with a wire (insulated) where current is drawn.
     
  12. BigA

    New Member

    Oct 27, 2010
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    Was a solution found for this issue? I am looking at a very similar problem that looks like it would have a slightly modified solution. Thanks.
     
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