Magneto Points Replacement Module

Discussion in 'The Projects Forum' started by debe, Dec 29, 2010.

  1. debe

    Thread Starter Well-Known Member

    Sep 21, 2010
    946
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    Posting info on completed project to rebuild a magneto ignition module that is out of production since 2005. The story of how it was done is under Ign Module/ Rev engineering. The Ignition points & condencer are removed & the module is wired in there place. It does advance the timing by 3Deg so if this is a prob the breaker plate if adjustable it will req moving. The circuit shown is for the coil mounted under the flywheel. If coil is mounted outside of flywheel, then the module wires will need to be reversed. Also Q1 is insulated from the piece of aluminum base. In the first pic the brown plastic module is what was avalable comercialy, The middle one is my test setup, the otherone is my constructed one set in ressin. The next pic is how its wired to coil. Third pic is module before sealing.
     
  2. moir

    New Member

    Sep 29, 2009
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    I just disassembled an Atom Red module to find out the parts values, and then found your article! The build is the two transistors attached to a ceramic board with thick film resistors printed on it. A surface mount capacitor is ingloriously lumped onto a couple contact points.
    The red module is used for outboard magnetos that have a bit different timing than the brown module, as these typically have internal E laminate coils. The circuit is identical, but the parts values (measured) are:
    R1 = 1.2K
    R2 = 3.3K
    R3 = 1.1K
    C1 = 0.5uF

    R2 is rather obviously trimmed after manufacture, and measured 3.3K on the money, so I presume it's what really defines the difference between modules.

    The circuit is described in US Patent 4163437
     
  3. debe

    Thread Starter Well-Known Member

    Sep 21, 2010
    946
    184
    Hi moir, thanks for the update on what you found. The module i built is being used on an old Tohatsu 5hp outboard. Somewhere else there is a long thread on how i arived at this point of construction.
     
  4. bikevouwer

    New Member

    Oct 11, 2011
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