Busch & Muller wiring diagrams

Am 05.08.2019 um 17:04 schrieb Frank Krygowski:
On 8/5/2019 5:05 AM, Rolf Mantel wrote:
Am 03.08.2019 um 01:41 schrieb bob prohaska:
This particular Lumotec Oval actually has two extra contact pairs;
one pair
goes to the taillight, the other was unused. I can't guess what it
was for.
It acts like a direct connection to the dyamo.

Actually, the standard contacts a

2* "from hub dynamo (cable)"
2* "from old-style dynamo (connector)"
2* "to rear light (connector)"

I'm curious about the internal differences related to a hub dynamo vs.
an old style dynamo. The differences in those dynamos' outputs are
almost entirely just differences in frequency of the AC.

Actually, they are less technical than philosophical:

A hub dynamo produces output continuously; therefore a light designed
for a hub dynamo needs an electric "off" switch.
A traditional dynamo has a physical "off" position and therefore does
not need an electric "off" switch.

The Lumotec Oval does provide an "off" switch. Without testing I would
not promise that
1) the "Off" switch works when power comes from the connectors
2) the "Off" switch ensures no power reaches the back light when light
comes from the connectors.

Frank Krygowski writes:

On 8/5/2019 5:05 AM, Rolf Mantel wrote:
Am 03.08.2019 um 01:41 schrieb bob prohaska:
This particular Lumotec Oval actually has two extra contact pairs;
one pair
goes to the taillight, the other was unused. I can't guess what it
was for.
It acts like a direct connection to the dyamo.

Actually, the standard contacts a

2* "from hub dynamo (cable)"
2* "from old-style dynamo (connector)"
2* "to rear light (connector)"

I'm curious about the internal differences related to a hub dynamo
vs. an old style dynamo. The differences in those dynamos' outputs are
almost entirely just differences in frequency of the AC.


According to the text, the second and third set are interchangeable.

The switches certainly work correct to ensure no power from a hub
dynamo to the rear light; I would not guess without testing what
happens with power from the dynamo connector to the read light when
the light is switched off.

The power settings are certainly aimed at Dynamo input (i.e. "fixed
power at 0.5A") to be split as 0.4A front and 0.1A rear; there is a
Zener diode somewhere inside as a voltage limiter to prevent
burn-though.

But all this extra wiring is completely independent on whether you
replace the front bulb by a front LED (with the appropriate
additional electronics inside).

The replacement LEDs from Reflectalite just pop into the same socket
as the original halogen bulb. I wonder if they have some sort of
regulating electronics built in. If so, it must be a very small
circuit.

I bought one of those LED bulbs (from Compass, not Reflectalite) for an
old-school tail light on my wife's bike. Works great. It definitely
has electronics built in, as do all the LED bulbs sold for home use, or
for retrofitting in flashlights built for incandescent bulbs. I don't
know if regulation is required, but AC to DC conversion is.

On 8/5/2019 11:13 AM, Rolf Mantel wrote:
Am 05.08.2019 um 17:04 schrieb Frank Krygowski:
On 8/5/2019 5:05 AM, Rolf Mantel wrote:
Am 03.08.2019 um 01:41 schrieb bob prohaska:
This particular Lumotec Oval actually has two extra contact pairs;
one pair
goes to the taillight, the other was unused. I can't guess what it
was for.
It acts like a direct connection to the dyamo.

Actually, the standard contacts a

2* "from hub dynamo (cable)"
2* "from old-style dynamo (connector)"
2* "to rear light (connector)"

I'm curious about the internal differences related to a hub dynamo vs.
an old style dynamo. The differences in those dynamos' outputs are
almost entirely just differences in frequency of the AC.

Actually, they are less technical than philosophical:

A hub dynamo produces output continuously; therefore a light designed
for a hub dynamo needs an electric "off" switch.
A traditional dynamo has a physical "off" position and therefore does
not need an electric "off" switch.

The Lumotec Oval does provide an "off" switch.Â* Without testing I would
not promise that
1) the "Off" switch works when power comes from the connectors
2) the "Off" switch ensures no power reaches the back light when light
comes from the connectors.

Good point about the "Off" switch.

I have a couple B&M headlights driven by old style sidewall dynamos. I
do have to check their "Off" switch from time to time to make sure the
headlight isn't inadvertently switched off.

--
- Frank Krygowski

Frank Krygowski wrote:

:I'm curious about the internal differences related to a hub dynamo vs.
:an old style dynamo. The differences in those dynamos' outputs are
:almost entirely just differences in frequency of the AC.

the bottle or bottom bracket dynamo tends to have a cable attached to
it. The other end of the cable plugs into the light. Hub dynamos do
not have a cable attached, so the light has one, the other end of
which plugs into the hub's output.


--
sig 91