120 VAC Auto Reverse Sequential Lights

Discussion in 'The Projects Forum' started by design41, Dec 6, 2013.

  1. design41

    Thread Starter New Member

    Dec 4, 2013
    4
    0
    Help with this circuit - it doesn't work. I had to substitute 2N3904 for Bel 187 because they are not available in the U.S.


    http://forum.allaboutcircuits.com/attachment.php?attachmentid=62292&stc=1&d=1386341592
     
  2. Ramussons

    Active Member

    May 3, 2013
    557
    92
    It wont. There is a mistake in the circuit. Then thyristors will not fire.

    The thyristor requires a +ve trigger between M1 and Gate. The between condition is not met in the circuit.

    Ramesh
     
  3. design41

    Thread Starter New Member

    Dec 4, 2013
    4
    0
    Hi Ramesh, thanks for info - my electronics knowledge is limited, can you show me how to correct it?
     
  4. Ramussons

    Active Member

    May 3, 2013
    557
    92
    Yes, but not in this forum :mad:

    This forum policy prohibits playing around with non isolated power (or words to that effect).

    Ramesh
     
  5. Dodgydave

    Distinguished Member

    Jun 22, 2012
    4,969
    744
    You need to use an opto-triac MOC3020, to isolate from the mains supply like this
     
  6. t06afre

    AAC Fanatic!

    May 11, 2009
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    Perhaps it would be better to use relays. Depending of the switching speed of course
     
  7. tracecom

    AAC Fanatic!

    Apr 16, 2010
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    I don't think that circuit is a violation of the TOS; there's no transformerless power supply there and no LEDs connected to mains. It's just a circuit that switches mains voltage - a circuit to be careful with, but not a restricted topic.

    6. Restricted topics. The following topics are regularly raised however are considered "off-topic" at all times and will result in Your thread being closed without question:

    • Any kind of over-unity devices and systems
    • Automotive modifications
    • Devices designed to electrocute or shock another person
    • LEDs to mains
    • Phone jammers
    • Rail guns and high-energy projectile devices
    • Transformer-less power supplies

    If You come across a thread or post discussing any of the above topics please report the thread so We can close, and if necessary remove, the offending thread/posts.
     
    design41 likes this.
  8. design41

    Thread Starter New Member

    Dec 4, 2013
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    These are triacs and they don't need a connection between the gate and M1. They just need a trigger to the gate.
     
  9. t06afre

    AAC Fanatic!

    May 11, 2009
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    Did you find this circuit on the? Because it is lot of bad circuits ideas floating around in cyber space. And this clearly on of them, it is flawed in many ways
     
  10. design41

    Thread Starter New Member

    Dec 4, 2013
    4
    0
    Yes, I did pull it from an electronics site, but it was a 6 light circuit and I downsized to 3. It seems so simple - the IC 1 & IC 2 circuit is cut and dried being used thousands of times! The triacs need a pulse to trigger and I figured that since I had to substitute Q1-3 that a change in resistor values was in order.
     
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