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Tech. Advice: Firefly Engines
Can anyone explain how the Firefly ignition works?
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<blockquote data-quote="billirwinnz" data-source="post: 172988" data-attributes="member: 1697"><p>Hi</p><p></p><p>I'm familiar with the energy transfer ignition systems on small Hondas and the Ducati CDI system. The Firefly system is different from both. There is no dedicated primary ignition coil. Just an alternator and a coil with points and condensor like a car. After lots of reading and testing I believe that I know how the system is supposed to work. It's like a cross between a magneto and a conventional coil ignition system.</p><p></p><p>Instead of the alternator powering a battery which fires the coil via points and condensor, the alternator output goes direct to the coil. The alternator is a 9watt (yes only 9!) unit that outputs 6v AC to drive the bicycle lights and ignition. The alternator drive gear is timed so that the peak of the AC voltage wave occurs just before the points open. For 6v RMS this will be about 8-9 volts which is about the same as the primary voltage in a magneto. From that I deduce that the secondary coil should have about the same characteristics as a secondary coil in a magneto.</p><p></p><p>I was seeing only 1.1AC volts when I spun the alternator with my drill. Fitting new permanent magnets yielded only 0.9v so today I had the original magnets re-magnetised and re-fitted them. Still only 1.1v so I assume that there must be something wrong with the coils in the stator. That's a job for tomorrow.</p><p></p><p>Thanks for your interest and suggestions.</p><p></p><p>I'll let you know how I get on.</p><p></p><p>Cheers Bill</p></blockquote><p></p>
[QUOTE="billirwinnz, post: 172988, member: 1697"] Hi I'm familiar with the energy transfer ignition systems on small Hondas and the Ducati CDI system. The Firefly system is different from both. There is no dedicated primary ignition coil. Just an alternator and a coil with points and condensor like a car. After lots of reading and testing I believe that I know how the system is supposed to work. It's like a cross between a magneto and a conventional coil ignition system. Instead of the alternator powering a battery which fires the coil via points and condensor, the alternator output goes direct to the coil. The alternator is a 9watt (yes only 9!) unit that outputs 6v AC to drive the bicycle lights and ignition. The alternator drive gear is timed so that the peak of the AC voltage wave occurs just before the points open. For 6v RMS this will be about 8-9 volts which is about the same as the primary voltage in a magneto. From that I deduce that the secondary coil should have about the same characteristics as a secondary coil in a magneto. I was seeing only 1.1AC volts when I spun the alternator with my drill. Fitting new permanent magnets yielded only 0.9v so today I had the original magnets re-magnetised and re-fitted them. Still only 1.1v so I assume that there must be something wrong with the coils in the stator. That's a job for tomorrow. Thanks for your interest and suggestions. I'll let you know how I get on. Cheers Bill [/QUOTE]
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Tech. Advice: Firefly Engines
Can anyone explain how the Firefly ignition works?
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