I was just leafing through some of the articles posted and wondered why people were attempting to rewire dynamos. 40 years ago I solved the problem of the lack of a generator on my Velocette by installing a Fiat 500 car generator. I then approached Dave Lindsley who put me in touch with John Gardner who made me a regulator/cutout to suit. This was very successful. I had an additional clip-on with a 55watt spot hanging wired into a relay switched dip beam circuit. The main headlamp had an E type Jaguar sealed beam unit. I could see at night!
When I tackled the Vincent engine I already had the standard Miller generator. Mr Gardener supplied his standard offering this time, in this one he limits the field coil voltage to 6 volts. Now I have no experience to report since shortly after completing the Norvin rebuild the winter was upon us and then I was sent to Saudi Arabia for work. (Insert usual long story of family, working abroad, paying for the kids)
The point being is that the Achilles heel of the old 6 volt systems was the vibrating contact points of the regulator. Mount such on a piece of vibrating machinery and it does not perform too well. In the diesel engined air compressors on site in those days the regulator box was rubber mounted to help it survive.
Whereas in fact electronically it is relatively trivial to design a circuit to regulate the voltage to 14.2v. The trick is making it bike and weather proof. This is where the JG unit scores being firstly designed by an electronics engineer and secondly it is potted inside a die cast box so it is vibration and water proofed.
I do not know whether JG units are still around. They were a straight forward substitution for the old box. Change the battery and the bulbs for 12 volt items and let there be light! No mods were required to the dynamo itself.
When I tackled the Vincent engine I already had the standard Miller generator. Mr Gardener supplied his standard offering this time, in this one he limits the field coil voltage to 6 volts. Now I have no experience to report since shortly after completing the Norvin rebuild the winter was upon us and then I was sent to Saudi Arabia for work. (Insert usual long story of family, working abroad, paying for the kids)
The point being is that the Achilles heel of the old 6 volt systems was the vibrating contact points of the regulator. Mount such on a piece of vibrating machinery and it does not perform too well. In the diesel engined air compressors on site in those days the regulator box was rubber mounted to help it survive.
Whereas in fact electronically it is relatively trivial to design a circuit to regulate the voltage to 14.2v. The trick is making it bike and weather proof. This is where the JG unit scores being firstly designed by an electronics engineer and secondly it is potted inside a die cast box so it is vibration and water proofed.
I do not know whether JG units are still around. They were a straight forward substitution for the old box. Change the battery and the bulbs for 12 volt items and let there be light! No mods were required to the dynamo itself.