LED Traffic Light using 555 timer

Discussion in 'The Projects Forum' started by HEENA, Apr 19, 2009.

  1. HEENA

    Thread Starter New Member

    Apr 19, 2009
    1
    0
    LED Traffic Lights

    please give me the explanation of its circuit how it works
     
  2. bertus

    Administrator

    Apr 5, 2008
    15,648
    2,347
    Hello,

    Do you have a circuit that we can explain to you?

    Greetings,
    Bertus
     
  3. PRS

    Well-Known Member

    Aug 24, 2008
    989
    35
    Use a dual 555 timer to make a fast clock and a slow clock. Use the slow clock to switch the red and green lights. Use the slow one to pulse the yellow lights.

    With the clocks, drive a shift register or a sequencer to turn the clocks on and off. This will require some logic. I suggest using NAND or NOR gates.

    Good luck with your project! :)
     
  4. Bernard

    AAC Fanatic!

    Aug 7, 2008
    4,173
    397
    A friend had an old traffic light pole and needed lights, so I gave him a completed board driving 3 100W bulbs. Used 3 555's and a 4002 as a neg NAND and an inverter. Timing: G, 1M & 47μF; Y, 130k & 4.7μF; R, 1M & 47μF. G cap. coupled to Y, also Y to R. All 3 outputs fed back to 4002, then inverted and fed to R in[ pin 2]. Schemetic too faded to scan. Outputs triggered SCR's.
     
  5. PRS

    Well-Known Member

    Aug 24, 2008
    989
    35
    Interesting project, Bernard. I have two hobbies: Woodworking and electronics. I plan to combine them into making one of those old in-the-middle-of-the-street four-way traffic lights. It should make a nice piece of artwork for the livingroom -- and a great conversation piece. I have the digital circuit all worked out, but I'm not sure where I put it.
     
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