Simple Timer switch (Total NOoB)

Discussion in 'The Projects Forum' started by zerocool5878, Jun 12, 2009.

  1. zerocool5878

    Thread Starter New Member

    Jun 12, 2009
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    Hi guys i was hoping someone here could help me out. I am looking to make a switch that will basicly touch to wires together for less then a second and to repeat every 3-8 seconds. Im sure its very simple to do but I will be honest i don't have a clue. I can solder very well and figured i could try it out. I am thinking maybe a 555 timer and a relay or something.

    Any help you can offer would be greatly appreciated.
     
  2. thingmaker3

    Retired Moderator

    May 16, 2005
    5,072
    6
    Bill Marsden is working out the details of his 555 tutorial, which will be available here soon. In the mean-time, you can read Tony Van Roon's 555 tutorial: http://www.uoguelph.ca/~antoon/gadgets/555/555.html

    The "astable multivibrator" circuit should work well for your needs. Choose values for R1, R2, and C1 which will give a T1 time of "less than a second" and a T1+T2 time of "3 - 8 seconds."

    Depending on how much current your relay coil needs, you mght have to drive the relay with a MOSFET or a Darlington Transistor.

    Once you can provide more details (relay size or type, operating voltages), we can help!

    Welcome to All About Circuits!!
     
  3. Wendy

    Moderator

    Mar 24, 2008
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    What kind of current and voltage are you talking about using. A 555 can control a relay, but you need to pin the times down a little. Do you want the on time to be ½ seconds? Same thing ThingMaker3 asked, only worded differently.

    This makes me think I probably need to include at least one relay project in the 555 chapter, to show how to do it.

    Here is the basic information...

    [​IMG]
     
  4. zerocool5878

    Thread Starter New Member

    Jun 12, 2009
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    Not sure but I would like to get the parts from radio shack. Basicly I am trying to open an xbox controller and solder 2 wire onto the "A" button and I just want them to touch for a half second and repeat every 3-5 seconds. I don't have anything except the controller right now but I will go and buy the stuff as soon as I know what I need.
    I would like to use a ac wall adaptor for power.

    I really appreciate the help.
     
    Last edited: Jun 13, 2009
  5. Wendy

    Moderator

    Mar 24, 2008
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  6. zerocool5878

    Thread Starter New Member

    Jun 12, 2009
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    Ok i have this working with just an LED to get the timing right.

    Im using a 1M Potentiometer for R1
    and a 10k resistor for r2
    with a 10uf cap

    I need to know how I hook up the relay.

    Do I simply disconnect the LED and hook those leads up to a NO relay and then when it would blink the relay would close and touch my wires?

    Sorry im sure i sound stupid but this is my first project.

    Thanks again
     
  7. Wendy

    Moderator

    Mar 24, 2008
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    Not sure I understand the question. The schematic I drew shows how the relay is connected to the 555. A relay is a electrically operated switch, the contacts will be in time with the 555. Since I couldn't know what relay you were planning on using I showed a transistor, which increased the drive of the 555.
     
  8. franzschluter

    Active Member

    Jun 1, 2009
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    Uhm no it won't work. You need to hook up a transistor then output of transistor will go to relay. You need this because a 555 timer can barely output a LED light. If you plug a relay it would be barely able to switch it. You need to get the extra power juice from a transistor and not from the 555s output.

    I also see you want to make a button that will function as a rapid fire button? Am I right? :D
    If so I have built something similar in the past using transistors.

    Cheers
    Franz

    Cheers
    Franz
     
  9. hgmjr

    Moderator

    Jan 28, 2005
    9,030
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    Bill's example circuit in the #3 post in this thread shows the added transistor that has been recommended in order to drive the relay.

    hgmjr
     
  10. zerocool5878

    Thread Starter New Member

    Jun 12, 2009
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    I have this working well without the transistor. I may however need it for my next problem.

    I want to control multiple buttons at the same time. So say that I need the "A" button pressed on 3+ different devices. I tryed to hook them all to the relay and it doesnt work. It will only work one at a time. because it is basicly touhing all 6 wires together and somehow messing it up. Is there something I can do to make it touch all three buttons seperatly but at the same time? Would i need a relay for each button? If so i think I may need the transistors as im not sure my current setup will switch 3 or more realys.
     
  11. Wendy

    Moderator

    Mar 24, 2008
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    It is hard to say, many relays come with multiple contacts, which you can use. I suspect the most you can find is 2 sets, so that means more than one relay.

    The transistor is not optional, but you can use one transistor for several relays.
     
  12. zerocool5878

    Thread Starter New Member

    Jun 12, 2009
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    ok I got a transistor and I hooked it up and it seems to be working but im not sure I hooked it up correctly so if I did it wrong could you tell me. All I know is that it does power 2 relays but I have to get back to the store to get a few more to see if its going to work. For all I know the timer might be doing all the work and the transistor doing nothing.

    Anyway I am using a 2N3906-PNP

    I connected a wire from pin 3 on the timer to the Base
    Then grounded the collector
    and hooked the emitter to one side of the relay

    The other side of the relay to Power.

    I have no way to make a diagram of this because im really new to this stuff and I can barly read the ones you guys put up.

    Thanks for your help
     
  13. Wendy

    Moderator

    Mar 24, 2008
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    I already diagrammed it, did you use that one?
     
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