The AG and FG are Dynohubs (I have an AG), built into the same shell as 3 or 4-speed gears. So it seems likely that only the wiring was different.
> I'd be interested in hearing from anyone who has used one of these systems, just to see what it was like.
Me too. These things are rare. They were only used on the top models and many were probably ruined by corroding batteries.
I ride most days in winter using a Dynohub, but no batteries. Now fitted with LEDs and a super-capacitor standlight.
After wasting time on the S-A Heritage website, it seems that the evolution was:
1937/9 ??: a small battery in the headlamp, manual switch-over.
1945: The tube holder, with sealed lead-acid accumulators. Switchover unknown.
1948?: Dry batteries in tube, manual
1951: "Filter switch unit", automatic switchover and a very small charging current: "depolarisation".
Some variants may have been available together, as the accumulators are mentioned in a 1950 advert.
Edit: Reading the fine print in Steve's post above, it seems the accumulators were not sealed: "dry form", but needed to be topped-up!
That sounds troublesome, and may explain the switch to dry cells.
Last edited by gilesa; 01-11-22 at 07:44 AM.
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