On 2/24/2018 2:57 PM, Frank Krygowski wrote:
On 2/24/2018 2:57 PM, Joerg wrote:
On 2018-02-23 10:01, Tim McNamara wrote:


In my reference, generators mounted on the seatstay or
chainstays would
be "rear triangle" mounted. Because the frame is the
ground (earth on
the east side of the Atlantic), a single wire ran through
the frame
tubes. It connected to a carbon brush in the head tube,
which me
contact with an insulated ring on the steerer tube. A
wire from that
traveled through the front rack to the headlight.


And ground went via the bearings like it does in most
European dynamos set-ups? That was always a sick concept.
I don't think in automotive anyone would let a blooper
like that pass a design review. Yet that was and maybe
still is standard fare on most dynamo-equiped bicycles.

I agree that grounding via the bike frame is a bad idea. But
it's always been possible to run a two-conductor cord and
ground things properly, which is what I've done at least
since 1980.

And AFAIK all hub dynamos have always used proper grounding
through a two-conductor cord.


Right and a fascinating history, too.
When the British invented vehicle electric systems they had
to pick a number and six is a good number so they went with
6v. Positive Earth too, which is a good name for a garage
band or a cult. Anyway over time (usually a few months) they
discovered that linen wrapped single wire passing through
punched panel holes will let the essential smoke out, at
which point the car stops. So Sturmey Archer went with
double wire. Keeps the smoke in better. All was well after that.

--
Andrew Muzi
www.yellowjersey.org/
Open every day since 1 April, 1971