Planning to replace a power source ...
Jim Cheetham
I'm planning on getting an electric motor for my bike, but before I do
there's a small complication.
At the moment I have a hub dynamo generator, providing power to the
lights. It's an old SON, and I don't really know what it outputs.
http://www.peterwhitecycles.com/schmidt.asp seems to have some data at
the bottom and suggests that I'm probably running at 6 volts but
that's all I know ... and I don't want to replace the lights, they're
good ones (and the wiring for them runs inside the frame, ha ha).
The motor will replace the dynamo, because you can't have them both
living in the same wheel :-) I'd like to be able to grab some power
from the batteries in order to power the lights, but it's 12V and who
knows the current ... however I'm sure the manufacturer could answer
when their website http://daahub.com/ comes back up.
So what I'd like to do is to measure the output of the current dynamo,
to get a feel for what I'd have to be converting; and them come up
with an option for a tough weatherproof switcher so I can use either
the battery or the dynamo (assuming I switch the old wheel in, which
is an option of course)
The easiest way to get the dynamo spinning is to ride the bike --
because it is in the non-chain-driven front wheel. Any ideas for a
gadget I could use to measure the dynamo output over time while I ride
around?
-jim
Geoff Barkman
You will definately need a power regular in the circuit... based on a
7812 regulator ic with 2N2955 (MJ@ 2955) transistor current boosting.
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Cheers
Geoff Barkman
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Worik Stanton
> You will definately need a power regular in the circuit... based on a
> 7812 regulator ic with 2N2955 (MJ@ 2955) transistor current boosting.
>
regulators are good for dissipating an amp at (i think) te supply
voltage. LED lights are unlikely to draw that much. Just put it on a
heat sink.
W
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The hippies were right