Flatter Spoke Mounted LED Coil & Other Questions

[BretCahill]

I got the 120 v coil from a 6 v power supply (50 cents at used stuff store) and
a welding magnet (99 cents at Harbor Freight) and taped the coil and a bi color
LED to the spokes and the magnet to the seat stays. It was very dim but
encouraging. I bought a bridge rectifier (99 cents) and used the 1 m F
capacitor from the power supply and broke the magnet and taped half to the
chain stay half to the seat stay. This was a great improvement. The capacitor
actually keeps the LED on for the entire rotation at speeds above 5 mph.

Three questions:

1. Is there any flatter more efficient coil off the shelf? I would prefer
something in tape form like the wiring to a jet printer head. If not, how
could a flatter coil be fabricated for this application? It doesn't have to be
pretty, just cheap and not fall apart in the rain.

2. Reinserting the magnetic coupling plates into the coil not only added a lot
of weight, it didn't seem to brighten the light any. I'm glad I don't need the
heavy inserts but I was curious why they didn't help.

3. Why was the bi color LED in the first unrectified experiment going from
green to red to green? Shouldn't it just be R to G or G to R?


Bret Cahill

 

[Watson A.Name - "Watt Sun]

In article <20030928144511.00367.00000295@mb-m07.aol.com>,
bretcahill@aol.com mentioned...

I got the 120 v coil from a 6 v power supply (50 cents at used stuff store) and
a welding magnet (99 cents at Harbor Freight) and taped the coil and a bi color
LED to the spokes and the magnet to the seat stays. It was very dim but
encouraging. I bought a bridge rectifier (99 cents) and used the 1 m F
capacitor from the power supply and broke the magnet and taped half to the
chain stay half to the seat stay. This was a great improvement. The capacitor
actually keeps the LED on for the entire rotation at speeds above 5 mph.

Three questions:

1. Is there any flatter more efficient coil off the shelf? I would prefer
something in tape form like the wiring to a jet printer head. If not, how
could a flatter coil be fabricated for this application? It doesn't have to be
pretty, just cheap and not fall apart in the rain.

Guys in alt.solar.photovoltaic NG have pointed to articles for DIY
wind turbines. I think one good online source of info is Home Power
magazine. One guy uses a high strength magnet on the rotor and then
makes his own coils, which are pancake flat. He goes out in the sand
with the magnet and collects iron powder, enough to fill a pie tin,
I'd guess. He mixes it with a binder, might be epoxy, and forms it
around the coils to concentrate the magnetic field. Some of these can
put out 12V at several amps, good enough to charge a car battery. He
uses a lotta wood, so it might not be good for a wet or rainy
environment. Another generator uses a brake rotor. Check out the
articles in back issues. http://www.homepower.com/
Here's another good site for a homemade generator.
http://www.picoturbine.com/

2. Reinserting the magnetic coupling plates into the coil not only added a lot
of weight, it didn't seem to brighten the light any. I'm glad I don't need the
heavy inserts but I was curious why they didn't help.

3. Why was the bi color LED in the first unrectified experiment going from
green to red to green? Shouldn't it just be R to G or G to R?

Bret Cahill

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