ignition coil driver

  1. Tinbasherdan

    Tinbasherdan Bodger in chief

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    4,502
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    for the radial, i need a booster boil as the on starting the impulse mags dont generate a strong enough spark to start the engine. you can get dedicated booster coil set ups for around 100 quid, but you can also use an ignition coil off a car. now im no electrical genius, all i know is i need something to drive the ignition coil, so brains of the forum, throw me ideas!!
     
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  2. 8ob

    8ob Forum Supporter

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    Get creative and fit a donkey engine on the rig to spin it up faster :thumbup:

    Bob
     
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  3. 500e

    500e Always buy fire insurance a flood is hard to start

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    Are you looking for something like the "Shower of Sparks" on the Lycoming's ?
    Only ever had 1 boil it sure did not need a boost :(
     
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  4. Tinbasherdan

    Tinbasherdan Bodger in chief

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    4,502
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    You can get a hand cranked booster coil, sod that though
     
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  5. Tinbasherdan

    Tinbasherdan Bodger in chief

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    I’ve not heard them called that, but probably. The yanks call them starting vibrators (oooh er missus)
     
  6. 500e

    500e Always buy fire insurance a flood is hard to start

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    Location:
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  7. 500e

    500e Always buy fire insurance a flood is hard to start

    Messages:
    3,801
    Location:
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  8. merryman Member

    Messages:
    457
    Location:
    Lancaster, England
    That starting "vibrator system" seems a little like the trembler coil system used on model T Fords. Bit puzzled that your impulse mags not producing a decent spark. The whole point of "impulse" is to increase the spark for starting. I have only come across one, on a Jap donkey engine and was suitably impressed by the size of the spark it produced at the low speed of a hand cranked Jap.
     
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  9. Tinbasherdan

    Tinbasherdan Bodger in chief

    Messages:
    4,502
    Location:
    Bolton, England
    They can- and will eventually start on the mags alone but it’s hit and miss. I suppose they’re emptying quite a large amount of fuel into the bore and as such Need a hefty spark
     
  10. 500e

    500e Always buy fire insurance a flood is hard to start

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    Location:
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    Used to make electric fence units out of a coil relay & capacitor, vary the cap for spark frequency
     
  11. Tinbasherdan

    Tinbasherdan Bodger in chief

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    Location:
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    i tell a lie, they arent impulse coupled! trying to do too many things whilst writing the post
     
  12. Parm

    Parm I have fun doing stuff

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    Trust you @8ob, I bet you’ve got at least one spare one kicking around, lol
     
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  13. eddie49 Member

    I think that you need something that will electronically simulate a rotating distributor cam and a contact breaker. You could start with an add-on reactive or capacitive discharge ignition driver ( CDI ignition box ), such as a Sparkrite:

    https://www.ebay.co.uk/itm/Sparkrite-TX2002-electronic-ignition-system/303276317484

    or a Lumenition unit:

    https://www.ebay.co.uk/itm/lumenition-electronic-ignition-Rs2000-Escort-Rally/283608967465

    https://www.ebay.co.uk/itm/Lumeniti...ctronic-Ignition-Kit-Car-Classic/163854073080

    and then use a variable-speed oscillator to trigger it ( instead of the distributor pick-up coil or optical shutter ).
     
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  14. HughF

    HughF Member

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    Drive the coil with a Bosch bip373 Darlington driver, trigger the circuit (google for the reference design) with a pickup on the crank at the correct point...
     
  15. Tinbasherdan

    Tinbasherdan Bodger in chief

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    4,502
    Location:
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    Just needs to b triggered on a switch, on whilst starting, then flick It off
     
  16. eddie49 Member

    So there is no need to synchronise the spark with crank position, you just want a random "shower of sparks" ?
     
  17. Tinbasherdan

    Tinbasherdan Bodger in chief

    Messages:
    4,502
    Location:
    Bolton, England
    Yes, essentially it just needs to feed a ht supply directly to the dizzy, then be turned off once the engines running on the mags
     
  18. Tinbasherdan

    Tinbasherdan Bodger in chief

    Messages:
    4,502
    Location:
    Bolton, England
    Apologies for the poor spelling tonigh, I’m fighting my phone-screen has gone haywire
     
  19. eddie49 Member

    The simple answer would be to buy the Lumenition unit, connect it to an ignition coil, and spin the optical shutter disc with a small 12v motor.
    Otherwise, here is a slightly more sophisticated circuit, which uses an NE555 timer to drive a 1RF640 MOSFET to trigger an ignition coil:

    ignition-coil-circuit-diagram.jpg

    This circuit was designed as a type of "electric fence" - it generates high voltage pulses continuously, as suggested by 500e.
    The frequency is selected by the 100K pot, and also the actual value used for the "0.1uF" capacitor.

    http://www.circuitdiagramworld.com/.../HV_Ignition_Coil_Driver_using_555_19841.html
     
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  20. HughF

    HughF Member

    Messages:
    5,298
    Location:
    Work: Dorchester, Workshop: Corfe Castle, Wife's place: Frome
    This is exactly what you want... Build this...
     
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