Firefly Generator

Sounds like an interesting concept.. is that along the same lines as those "Shake Lights"? Maybe the
opposite way with the coil and the LED on the fork and a few magnets on the wheel rotating around...
I guess the prob would the light would go out fairly quickly after you stopped. I find it to be just
as important to be visible when stopped at a light as on the road as well..

Mike mikebeauchamp.commikebeauchamp.comOpen ↗

"BretCahill" <[email hidden]> wrote in message
"]news:[email hidden]...

Quoted message said:

Has anyone tried small coils & LEDS on spoke ends and hanging a magnet off

the

Quoted message said:

brakes? A capacitor or other simple circuit could keep the LED on for a

full

Quoted message said:

circle and regulate the voltage.

This would be cheaper than batteries even if the battery lasted forever.

The

Quoted message said:

size and weight should be about the same.

Bret Cahill

BretCahill said:

Has anyone tried small coils & LEDS on spoke ends and hanging a magnet off the brakes? A capacitor
or other simple circuit could keep the LED on for a full circle and regulate the voltage.

I imagine you'd be better off with a small conventional dynamo. Energy doesn't come for free out of
nowhere; you still have to generate it.

Maybe a really small dynamo turned by the wheel and some LEDs.

Quoted message said:

Bret Cahill

--
Rick Onanian

[email hidden] (BretCahill) wrote in message
news:<[email hidden]>...

Quoted message said:

Has anyone tried small coils & LEDS on spoke ends and hanging a magnet off the brakes? A capacitor
or other simple circuit could keep the LED on for a full circle and regulate the voltage.

This would be cheaper than batteries even if the battery lasted forever. The size and weight
should be about the same.

I remember seeing something like this, but all I could come up with on Google is this discussion:

ihpva.org006704.htmlOpen ↗

The BCQ mentioned there is Bike Culture Quarterly, if I remember correctly.

Something that has to rub against the wheel is probably going to be a lot less efficient no? Think
about the noise and the friction and the heat...

Passing a magnet through a coil would be a lot less friction (no physical friction) and no heat or
noise. I'm not a physics person though.. so I can't really explain for sure. I'm just assuming. I
can see the possible use of the magnet/coil thing over the dynamo thing.

Mike mikebeauchamp.commikebeauchamp.comOpen ↗ "Rick Onanian" <[email hidden]> wrote in message
"]news:[email hidden]...

Quoted message said:

BretCahill said:

Has anyone tried small coils & LEDS on spoke ends and hanging a magnet off the brakes? A
capacitor or other simple circuit could keep the LED on for a full circle and regulate the
voltage.

I imagine you'd be better off with a small conventional dynamo. Energy doesn't come for free out
of nowhere; you still have to generate it.

Maybe a really small dynamo turned by the wheel and some LEDs.

Quoted message said:

Bret Cahill

--
Rick Onanian

Mike Beauchamp said:

Something that has to rub against the wheel is probably going to be a lot less efficient no? Think
about the noise and the friction and the heat...

It's not necessary to have a friction connection to the wheel. How about a geared connection? A
circular rack could be clipped to the spokes around the center on the left side, and a pinion
fastened to the fork (or a chain/seat stay for rear). This could also double as a speed sensor, so
you wouldn't need a seperate computer.

Quoted message said:

Passing a magnet through a coil would be a lot less friction (no physical friction) and no heat or
noise. I'm not a physics person though.. so I really explain for sure. I'm just assuming. I can
see the possible use of the magnet/coil thing over the dynamo thing.

True, but I imagine that your system would weigh more; further, it would necessarily be weight at
the outside of the wheel, where it has more intertia (meaning, more torque required to accelerate).

--
Rick Onanian

Mike Beauchamp said:

"Rick Onanian" <[email hidden]> wrote in message

Quoted message said:

I imagine you'd be better off with a small conventional dynamo. Energy doesn't come for free out
of nowhere; you still have to generate it.

Something that has to rub against the wheel is probably going to be a lot less efficient no? Think
about the noise and the friction and the heat... Passing a magnet through a coil would be a lot
less friction (no physical

Congratulations, you have reinvented the hub dynamo. Well done!
--
David Damerell <[email hidden]> Kill the tomato!

David Damerell said:

Quoted message said:

Passing a magnet through a coil would be a lot less friction (no physical

Congratulations, you have reinvented the hub dynamo. Well done!

Actually, I was advocating hub dynamo; he was talking about magnet on fork, coils at rim end of each
spoke, with LED attached directly to coil.

--
Rick Onanian

Rick Onanian said:

Quoted message said:

Quoted message said:

Passing a magnet through a coil would be a lot less friction (no physical

Congratulations, you have reinvented the hub dynamo. Well done!

Actually, I was advocating hub dynamo; he was talking about magnet on fork, coils at rim end of
each spoke, with LED attached directly to coil.

Two different "he"s, as would be more easily seen if you preserved attribution lines. Some AOLer,
the original poster, advocated this baroque spoke system. You responded suggesting a dynamo. Mike
Beauchamp responded misinterpreting you as meaning specifically a bottle dynamo, worrying about the
friction on the wheel, and pointing out that moving a magnet and coil near each other would be more
efficient. I point out (as you of course know) that a hub dynamo already embodies this principle;
but Mike Beauchamp is not responsible for the original strange idea.
--
David Damerell <[email hidden]> Kill the tomato!

Woo! Someone mentioned my name in a post!

Mike mikebeauchamp.commikebeauchamp.comOpen ↗

"David Damerell" <[email hidden]> wrote in message
"]news:[email hidden]...

Quoted message said:

Rick Onanian said:

Quoted message said:

>Passing a magnet through a coil would be a lot less friction (no physical
Congratulations, you have reinvented the hub dynamo. Well done!

Actually, I was advocating hub dynamo; he was talking about magnet on fork, coils at rim end of
each spoke, with LED attached directly to coil.

Two different "he"s, as would be more easily seen if you preserved attribution lines. Some AOLer,
the original poster, advocated this baroque spoke system. You responded suggesting a dynamo. Mike
Beauchamp responded misinterpreting you as meaning specifically a bottle dynamo, worrying about
the friction on the wheel, and pointing out that moving a magnet and coil near each other would be
more efficient. I point out (as you of course know) that a hub dynamo already embodies this
principle; but Mike Beauchamp is not responsible for the original strange idea.
--
David Damerell <[email hidden]> Kill the tomato!

"BretCahill" <[email hidden]> wrote in message
"]news:[email hidden]...

Quoted message said:

Has anyone tried small coils & LEDS on spoke ends and hanging a magnet off

the

Quoted message said:

brakes? A capacitor or other simple circuit could keep the LED on for a

full

Quoted message said:

circle and regulate the voltage.

This would be cheaper than batteries even if the battery lasted forever.

The

Quoted message said:

size and weight should be about the same.

Yes something like that's been done. There was a unit that used a magnet on a spoke and a coil in
the light . It flashed brightly on each pass. Forgot the brand name but there are some
ten-year-old-units on customers' bikes that are still running well.

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

"A Muzi" <[email hidden]> in

Quoted message said:

Message-id: <[email hidden]> writes:

. . .

Quoted message said:

There was a unit that used a magnet on a spoke

I thought of that too but I figured a magnet would weigh more than a small fine wire coil +
capacitor + LED.

Besides, revolving lights really are eye catchers.

Quoted message said:

and a coil in the light . It flashed brightly on each pass.

Smooth out the voltage with a capacitor or a battery.

Or put a magnet on several or all spokes for a flashing light.

Bret Cahill

BretCahill said:

"A Muzi" <[email hidden]> in

Quoted message said:

Message-id: <[email hidden]> writes:

. . .

Quoted message said:

There was a unit that used a magnet on a spoke

I thought of that too but I figured a magnet would weigh more than a small fine wire coil +
capacitor + LED.

Besides, revolving lights really are eye catchers.

Quoted message said:

and a coil in the light . It flashed brightly on each pass.

Smooth out the voltage with a capacitor or a battery.

The problem with this is that the approaching voltage is the opposite of the receding voltage,
so the magnet will charge the capacitor (taking away from the diode) then discharge the
capacitor when the diode would normally be off anyway because it's reversed biased -- lessening
the amount of light.

I'd put one of the double color leds on there. One current flow direction it's red, the other it's
green. So what you'll get is a led that flashed red/green with every rotation (or green/red
depending on coil wind/magent orientation). I've done this to demonstrate simple windmills for kids.
Or, you can just put 2 parallel diodes reversed on each coil -- 1st one'll come on, then switch to
the other as the magnet passes the coil.

Quoted message said:

Or put a magnet on several or all spokes for a flashing light.

Good idea 🙂

Oh, and I'd recommend Neodymium magnets. Best magnetic strength/weight.
wondermagnet.commain.shtmlOpen ↗ often has 'em on ebay, or get 'em direct.

David