3 channel thyristor system

Discussion in 'General Electronics Chat' started by Maddoktor, Dec 20, 2011.

  1. Maddoktor

    Thread Starter New Member

    Dec 20, 2011
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    Hi guys
    I have a problem with a color music.
    http://img685.imageshack.us/img685/649/colorshema.gif

    I share the following tests
    A little further up I pointed out the scheme and sees explanation and principal scheme.
    tested in both cases: the stage is the lamp or the cathode of the thyristors

    If I power phase and fall directly to the lights - no network in the metal parts - microphone, potentiometer and others. The scheme does not blink

    If I power phase and fall directly to the cathode of the thyristor and hence part of the common forms of traffic - then I phase in all metal parts.
    Fazomera a touch of the table microphone (shell) -> scheme earns great, and if touched fazomera to one of the transistors T2 T3 T4 - lit a lamp.

    Guess is that if Kunka touch with one microphone - everything is OK - but if you touched something metal Kunka other and connected to the network - you beat me very serious failure - and I will be able to back him
     
    Last edited: Dec 20, 2011
  2. joeyd999

    AAC Fanatic!

    Jun 6, 2011
    2,690
    2,754
    That's quite a dangerous circuit you have there...might violate the board rules...I am not sure anyone is going to help you...
     
  3. bertus

    Administrator

    Apr 5, 2008
    15,648
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    Hello,

    The circuit is UNSAFE as ALL is connected to the mains.

    Here is an overview of the UNWANTED connections.

    [​IMG]

    By using opto-isolators, like the MOC series, you can make the circuit safe.
    Also the connection at the transformator MUST be removed.
    The circuit also will work better with triacs in stead of the thyristors.

    Bertus
     
  4. Maddoktor

    Thread Starter New Member

    Dec 20, 2011
    7
    0
    I contacted the wrong bridge primary and secondary winding of the transformer.
    After this change - the scheme work perfectly
     
  5. bertus

    Administrator

    Apr 5, 2008
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    Hello,

    You STILL did NOT isolate the mains.
    The circuit IS dangerous.

    I have given instructions how to make it safe.

    Bertus
     
  6. SgtWookie

    Expert

    Jul 17, 2007
    22,182
    1,728
    Bertus is correct; the circuit is not safe.

    The secondary side of the transformer must be disconnected from the primary side. It should be connected to earth (ground) instead. That way, if there is a fault in the transformer causing a short to the secondary side, a fuse will blow instead of someone getting electrocuted.

    There should also be a fuse between the hot line and the transformer primary.

    The MOCs he is referring to are pretty inexpensive. Here's an example:
    http://search.digikey.com/us/en/products/MOC3023SM/MOC3023SM-ND/400427

    Please do make the necessary modifications, or your project will not be safe.
     
  7. Maddoktor

    Thread Starter New Member

    Dec 20, 2011
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    Last edited: Dec 21, 2011
  8. bertus

    Administrator

    Apr 5, 2008
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    Hello,

    Yes, now the circuit is isolated and safe.

    Bertus
     
  9. Maddoktor

    Thread Starter New Member

    Dec 20, 2011
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    right for the second scheme, you mean it is safe?
     
  10. bertus

    Administrator

    Apr 5, 2008
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    Hello,

    The second schematic is correct.
    For more safety you can add the fuses as SgtWookie told you.

    Bertus
     
  11. Maddoktor

    Thread Starter New Member

    Dec 20, 2011
    7
    0
    Hello again boys:)
    I think a little change to the scheme:
    1: I will increase the value of C1 - to pass a low frequency microphone amplifier.
    2: Will it be necessary to increase the values ​​of C3, C7, C11 - to enable the scheme to respond to lower frequencies
     
  12. Maddoktor

    Thread Starter New Member

    Dec 20, 2011
    7
    0
    Last edited: Dec 28, 2011
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