help with a digital timer that turning a switch

Discussion in 'General Electronics Chat' started by jack148, Aug 25, 2015.

  1. jack148

    Thread Starter New Member

    Aug 25, 2015
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    hello everyone!
    i'm new here, and i'm sorry about my english.
    I'm a third year electric engineer student, and i want to do something:
    i want to build a electronic device that connected mechanically to a switch of light(in my house),
    with a display and buttons, and a micro-controller.
    It need to be able to get a input of hours, and turn the switch after those hours (mechanically, without connecting it to the wires of the switch).

    i want to start it with arduino, for prototyping...

    how can i start? what components do i need?
    thanks!
     
  2. MaxHeadRoom

    Expert

    Jul 18, 2013
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    How do you propose to do that without physical connection?
    Max.
     
    Vemuri Suresh Kumar likes this.
  3. jack148

    Thread Starter New Member

    Aug 25, 2015
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    it will be with physical connection! it will be stick to the panel of the switch, and turn off/on it with a kind of stick that will move from a motor.
    do i understandable? (sorry again about my english)
     
  4. AnalogKid

    Distinguished Member

    Aug 1, 2013
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    I think he's talking about a rod with a hole in the middle of it that drops down over a standard toggle light switch. Moving the rod back and forth with solenoids or a motorized actuator flips the toggle switch with no electrical contact with the house AC.

    ak
     
  5. jack148

    Thread Starter New Member

    Aug 25, 2015
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    Yes!!!!
    That is what i'm talking about!!!!!

    how can i do that?
     
  6. Dodgydave

    Distinguished Member

    Jun 22, 2012
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    the question is WHY do you want to do it that way????
     
  7. MaxHeadRoom

    Expert

    Jul 18, 2013
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    Something like a relay gives you galvanic isolation, without going to fancy mechanics?
    If manual control is no longer used, use the relay to switch the circuit.
    Max.
     
  8. mcgyvr

    AAC Fanatic!

    Oct 15, 2009
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    Do you want to use servos or solenoids or pneumatic cylinders to control the motion?
    How accurate do you need the time to be? Arduino can do timing without anything else but its not very accurate.
    If you need accuracy then you would need an RTC (real time clock) circuit.

    There are TONS of tutorials all over on the internet to do what you want..
    Have you tried searching already?

    Its simply a matter of some timing functions, display/menu functions and servo control.

    A simple 2x16 LCD, a button or two, a servo motor, a few 10k resistors, and an arduino is all you need to get started..

    As a 3rd year Engineering student you should be able to learn/get started on your own by now IMO.


    If you want to mechanically control the switch thats just fine.. Its just not the way most would do it (relay/SSR or similar).. But its your project and is safer than having to interact with hazardous voltages.
     
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  9. Alec_t

    AAC Fanatic!

    Sep 17, 2013
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    A hobby servo would be my choice as the mechanical actuator, assuming the switch has a conventional rocker or toggle.
     
  10. jack148

    Thread Starter New Member

    Aug 25, 2015
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    Thank's!!
    it's strange that i'm 3rd student and I don't know nothing abut that!
    i know only mathematics and physics....

    about searching internet's tutorials - i tried but without success...
    where can i search?

    thank you everyone!
     
  11. mcgyvr

    AAC Fanatic!

    Oct 15, 2009
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  12. jack148

    Thread Starter New Member

    Aug 25, 2015
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    thanks a lot.

    In the final version i want it without the arduino.
    is it ok for start with arduino and if it works change it to a simpler micro-controller?
     
  13. mcgyvr

    AAC Fanatic!

    Oct 15, 2009
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    Sure..
    But realize you may/will have to potentially rewrite the code from scratch/create new hardware,etc...

    Not sure why you wouldn't want to just keep the Arduino in the "final" version.. Maybe use an Arduino nano/pro mini if size is an issue.. This isn't a product you could sell or anything so I'm not sure why you would want to swap out the main device to make a "final" version..
     
  14. jack148

    Thread Starter New Member

    Aug 25, 2015
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    now i'm thinking... maybe i can connect the device to the house AC, i assume that i could find tutorial for this.

    thank's for everyone!!!
     
  15. MaxHeadRoom

    Expert

    Jul 18, 2013
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    As in a relay etc?
    Max.
     
  16. jack148

    Thread Starter New Member

    Aug 25, 2015
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    yes, as in relay.
     
  17. MaxHeadRoom

    Expert

    Jul 18, 2013
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    Here is one way using S.S. components which will be a little more compact than a relay and you could build it into a regular switch box.
    The opto isolator would be switched by the Arduino.
    http://www.eetimes.com/document.asp?doc_id=1278311
    You would need fig2 full wave control.
    Somewhere to start.
    Max.
     
  18. jack148

    Thread Starter New Member

    Aug 25, 2015
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    thanks.
    Just a general question:
    i want to use power supply for arduino, from wall outlet.
    do i need to buy somthing like that (i found in ebay at 1$), or i need to try building it? (as a newbe starter....)
     
  19. mcgyvr

    AAC Fanatic!

    Oct 15, 2009
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    Just buy a 9V power supply (ac/dc adapter, wall wart)
    Like this..http://www.amazon.com/9V-DC-Power-Adapter-Supply/dp/B004LX146Q
     
    jack148 likes this.
  20. jack148

    Thread Starter New Member

    Aug 25, 2015
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    It has only one output. the DC voltage that i need.
    what about the GRD?
     
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