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Modify Velleman Kit - Transistor Assisited Ignition, kit no. K2543

Discussion in 'Electronic Projects Design/Ideas/Reviews' started by sign216, Jan 12, 2017.

  1. spec

    spec Well-Known Member Most Helpful Member

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    I notice that the FT coils come in two types: encapsulated and oil filled. As oil filled coils are is far superior at dissipating heat, I suggest that you investigate getting an oil filled version of the FT1.5R or similar coil.

    spec
     
  2. sign216

    sign216 Member

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    Looking at the Yuasa battery catalog, I don't think a 20AH battery will fit. When I get home tonight I'll measure the bike's frame and see. 11 to 14AH might be it.

    You want a higher capacity battery to give some "room" when the bike is idling to power lights + ignition?
     
  3. spec

    spec Well-Known Member Most Helpful Member

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    Yes, a higher capacity battery is nearly always better, especially with lead acid batteries which do not like being discharged.

    If you have a battery charger we could put that on the battery for testing the coil.

    I will describe a 1 Ohm resistor and a 0.47 Ohm resistor and give a link. These resistors will be needed for testing. I will advise.

    spec
     
  4. dave

    Dave New Member

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  5. sign216

    sign216 Member

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    Spec,
    Work called me away to Wash D.C. for two weeks. It was a "pack your kit and leave Now" kind of thing.
    When I get back I'll measure the bike's frame to see what battery I can order.

    I already have a 6v charger, and an infrared thermometer to measure the coil's surface temp. The 6v charger is ancient, with no trickle feature, and might be too powerful to use in conjunction with testing the coil. When I return I'll give you the charger specs.

    If it's a good choice, I'm ordering a Pertronix basic oil-filled Flame-Thrower coil, part no. 40011, 1.5 ohm, 100:1 turns, with 6.4mH primary inductance. I think we decided that was the best choice for this application (thanks for the tip re oil vs epoxy filled coils).
     

    Attached Files:

  6. spec

    spec Well-Known Member Most Helpful Member

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    Thanks for info.

    Talk to you in a a couple of weeks.:)

    spec
     
  7. sign216

    sign216 Member

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    Before I buy a 6v battery and a 6v coil, maybe this is a good time to switch to 12v?

    Or, would 12v lights and accessories overtax an already marginal output? You recall how weak these vintage motorcycle electrics were.
     
  8. spec

    spec Well-Known Member Most Helpful Member

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    Hi Sign,

    Moving from 6V to 12V on a bike is normally a good move because the current will be halved, but I do not know about the specifics of your bike. Perhaps there is some information on the net from some of the specialist biker forums. But one thing that would need to be looked at, would be the magneto starting- would that work with a 12V coil? I suppose you could try the bike with a standard automobile coil with a primary resistance around 4 Ohms (possibly made up with a ballast resistor).

    About overloading the electrical system, the power consumed with both 6V and 12V systems would be the same, power being V * I. so, for example a 6V, 60W headlight would take 10A but a 12V, 60W headlight would only take 5A. By the way, speaking of lights I would definitely investigate LEDs, which would improve the light and radically reduce power consumption.

    There would be another bonus with going to a 12V system: the SMPS in the modified Vellerman ignition switch would not be required.

    spec
     
  9. sign216

    sign216 Member

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    I think you are right, the magneto starting might not function with a higher ohm 12v coil.
    As it is, the magneto starting is weak, and will only work with a push start. Kicking the starter is not enough.
    There's a user's group on Yahoo, let me ask them if anyone has made the switch.
     
  10. spec

    spec Well-Known Member Most Helpful Member

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    Is the magneto starting essential to you, especially as you are considering a higher capacity battery?

    Most bikes do not have a magneto starting option.

    spec
     
  11. sign216

    sign216 Member

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    Yes, magneto starting is really a great feature. It allows you to start and ride the bike if you have a dead battery. To keep things light and economical, cyles aren't built to the same reliability as cars, so any "back up" feature is welcome.

    I've got a vintage BMW cycle too, and Beamer was careful in the contruction to keep the lighting system separate from starting, so if there were issues you could at least have a ride home.

    I think the big switch from kick+magneto to battery+coil came about when people started demanding electric start, which required a robust battery and electical system. I heard manufacturers were happy to drop the magnetos, as they were more expensive than alternators.

    I'd have kick start on all my bikes, but it's no longer an option. The world is catering to babies, right?
     
  12. spec

    spec Well-Known Member Most Helpful Member

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    Yes, and I still have scars on my right shin to prove how macho I am.

    About changing to a 12V system- does your bike have a dynamo or an alternator?

    Would fitting two coils be an option?

    spec
     
  13. sign216

    sign216 Member

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    I believe it's a generator (or dynamo as you UK people say). The wire diagram doesn't show any rectifier.

    A second coil isn't an option, as rigging it up to spin isn't practical.

    It's looking like I'll have to stick a classic 6v system, although I'm open to ideas from you savants.
     
  14. spec

    spec Well-Known Member Most Helpful Member

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    generator = dynamo or alternator
    dynamo produces DC
    Alternator produces AC

    OK

    That would be the simpler option but perhaps not the best.

    In terms of charging a 12V battery I would recommend a 3V to NV input to 14.1V SMPS between the dynamo and the battery. That will give you the maximum battery charge at all engine speeds. Use an FT 12V (3 Ohm) 40KV coil, possibly with appropriate ballast resistor (2.2 Ohms).

    Change all bulbs to 12V LEDs. The ammeter, if one is fitted, will not need changing. The horn will not need changing. But any instruments will need to be checked for compatibility with 12V.

    About the mag start. As I said before, I would try the mag start with an old type automobile 12V coil to see if the bike starts. If it does- problem most likely solved as this indicates that the mag start will work with an FT 12V (3 Ohm) 40KV coil, probsbly without ballast resistor.

    spec
     
    Last edited: Jan 21, 2017
  15. shortbus=

    shortbus= Well-Known Member

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    Doesn't a bike like this have a flywheel mag? One with the generating coil on the interior of the flywheel. At least that's what most small bikes of that era used.
     
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  16. spec

    spec Well-Known Member Most Helpful Member

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    I don't know SB.

    But that makes a lot of sense and would solve a few problems.:)

    spec
     
  17. sign216

    sign216 Member

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    The generator coil is on the end of the flywheel. Spec, what problems does that solve?

    As for the switch to 12v, it looks like a "no go." Appears that I would lose the emergency magneto push start capacity. I'll make do with the fabulous 6v lighting system.
    And yes, led lights are part of the future.
     
  18. spec

    spec Well-Known Member Most Helpful Member

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    I was imagining, as SB suggested, that the emergency start system was like a magneto and did not use the ignition coil, but from what you say that is not the case.

    I am intrigued, why would you loose the emergency start by going to 12V. Who said that?

    spec
     
  19. spec

    spec Well-Known Member Most Helpful Member

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    Sign, I have been meaning to ask, can you still get decent 6V batteries at a reasonable price. If so, what sort of price would, say a 20A hr, 6V battery be?

    spec
     
    Last edited: Jan 22, 2017
  20. sign216

    sign216 Member

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    As you suggested, some bikes have separate coils for lighting and ignition (like the Gilera bike in the other thread on 6v AC volt regulator). It looks like this bike ('69 Wards/Benelli) has a single generator that is the sole electric provider. This makes sense, because it's got coil+battery ignition, so the generator merely has to keep the battery charged for everything to work.

    A bike with magneto + coil ignition is more likely to have separate coils for lighting and igntion, since spark and lights have different needs. The quick kick is the only source of the ignition spark, and that coil has to be made for that.

    As for losing the emergency push start if I convert to 12v, I surmised that. In short, if the batterys dead the instructions say that that upon flicking the "emergency battery bypass switch," you can push-start the bike. It's hard to parse out the wire diagram, but I think this disconnects the battery from the generator, so that the all of the generator's current goes to the ignition coil.
    So then the generator acts as a starting magneto. But the generator isnt a very good magneto; kicking the starter lever isn't enough. You have to give the bike a vigorous push start. Given that the generator barely functions as a starting magneto, I'm guessing that changing to a 12v ignition coil wouldn't allow it work in the emergency fashion.

    Attached are three different wire diagrams. Two are factory, and one was made by Alec_t on this board (thank you, Alec!). I've also attached a link to the owners+workshop manual.

    https://www.dropbox.com/s/e94r7zxj4x41dbf/250_350_Service_Owners_Parts.pdf?dl=0#
     

    Attached Files:

  21. spec

    spec Well-Known Member Most Helpful Member

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    Hi Sign,

    since my last post I have been investigating the 69WB and came to exactly the same conclusion as your above statement about the emergency start. In fact the method is dead simple.

    So, there is no reason that I can find, why you cant convert to 12V and still retain the emergency start, at least that is what I think.

    Just for the interest, I have done a schematic which, in theory anyway, will change the bike to 12V, eliminate the mechanical regulator, retain emergency start, and improve the battery charging and general efficiency of the bike electrical system.

    The scheme is only notional at the moment, but I could still draw up a schematic and post for your consideration.

    Or, after all the discussions, would you now just like to go for the 6V system?

    spec
     

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