These things look to good to be real...

http://www.kickstarter.com/projects/dynamodirk/magnic-light-get-new-energy?ref=category

Anyone care to explain exactly how this thing could work..and don't just say eddy currents..

What would one need to replicate this effect at home?

Thanks,

-luvv-

 

Evidently, current is induced in the spinning wheel by magnets located inside the unit. The resulting magnetic field in the wheel is converted to current in the unit by an inductive pick-up coil, which powers the system.

 

So um, this http://www.youtube.com/watch?v=7_-RqkYatWI

except in reverse

 

You'll notice by reading the first article, they discussed breaking due to the eddy currents.

 

You'll notice by reading the first article, they discussed breaking due to the eddy currents.

Noooo you wasn't allowed to say Eddy Current

Just another reason to love magnetic fields....

Wonder if the same principle could be applied to brake rotor, so i could power some super tacky rim lights

 

Their spelling is bad. They said Breaking but mean Braking.
The lights are turned on only during braking maybe so the rider does not get too tired with the eddy currents causing braking all the time. Then they say the system uses only a small amount of power (of course because it is hardly ever turned on).

The light will sell for $200.00 which is very expensive for a dim little brake light and it turns off when you are stopped. You still need a battery powered driving light at night.

 

Yea i don't care if the thing was gilded, not worth 200$ to me.

But the idea of remote power w/o batteries,wires,friction(i know the rim has friction) but still interesting.

I imagine the unit is ultra durable also w/ only external moving parts.

Just set my imagination going w/ all the possible implementation such a
device.

Who don't like trading kinetic energy for electric,i know i do

 

The lights are turned on only during braking maybe so the rider does not get too tired with the eddy currents causing braking all the time. Then they say the system uses only a small amount of power (of course because it is hardly ever turned on).

The way I read it is that it's taking energy whenever the wheel is moving, but the braking is minimal ( only equal to the energy required to illuminate the LED's plus some losses )

 

That's a brilliant idea! I'm afraid his attempt at bootstrapping the funding will cause him to wind up getting nothing from his invention, though. Some Chinese company will steal the idea and he will be left holding the bag. I think he would be better off trying to sell the idea to some big company (maybe he already tried that), and take a small percentage of what could be a lot of sales, rather than risk getting nothing in his attempt to get all the profits.

 

It takes pedalling energy to light the LEDs all the time, therefore they turn them off most of the time but turn them on only during braking until the bike stops, when they turn off again.

The energy is free only when you apply the brakes coasting downhill. But then of course you must pedal like mad to to up the hill on the other side.

 

This would take no more energy than the old style friction dynamo, which could be set to be on all the time. It's just a fraction on the energy applied to the pedals.

 

You could use the excess energy to power a small battery, which would handle the short stops.

 

This would take no more energy than the old style friction dynamo, which could be set to be on all the time. It's just a fraction on the energy applied to the pedals.

The Magnic light is on whenever the wheel is turning. Watch the video.

 

You could use the excess energy to power a small battery, which would handle the short stops.

The inventor addresses this issue in the comments section of his web site.

 

I'm afraid his attempt at bootstrapping the funding will cause him to wind up getting nothing from his invention, though.

Yes I think so too. Then somewhere they say that the actual price will be higher than $200.

Why would that be?

>$200 for a magnet, pickup coil and some electronics? While I understand that development has to be paid too, this is much too expensive.

 

If there is a permanent magnet inside the device and the wheel is moving it would induce eddy currents in the wheel right. But at constant speed wouldn't that current always be the same direction in relation to the device itself? Constant current, constant magnetic field , how can he pick this up?

Or is this due to irregularities of the wheels surface, distance to the device? (like NDT testing)

 

Ok so one of you elctro wizards up a rough schematic of how you think it works.

So i can start kludging something together...

I have only a rudimentary grasp of magnetic induced current, but what i cant really grasp is how the rim rotating speed alters it.

I mean in a transformer the current in induced in the core that is in extremely close proximity and not moving...

Does the rotation create a AC of some sort?

Nearly every coil i've made is extremely finicky, i would imagine that set up would have to very tolerant to variations in the distance and variations in the rim.

The guy claims it's all weather but what happens when you start picking up mud and road debris?

 

If there is a permanent magnet inside the device and the wheel is moving it would induce eddy currents in the wheel right. But at constant speed wouldn't that current always be the same direction in relation to the device itself? Constant current, constant magnetic field , how can he pick this up?

Or is this due to irregularities of the wheels surface, distance to the device? (like NDT testing)

The same question has been nagging me.

 

Only an alternating magnetic field's energy can be picked up with a coil.
The alternating magnetic field can either caused by an AC current in a stationary conductor or a DC current in a moving conductor.

I think it would be possible with a permanent magnet that can freely rotate inside the device...

 

Yea that's what i figured but if the moving object is a flat circular conductor ie. a bike rim.

It would seam it wouldn't make much a ripple, guess it would depend on small irregularity in the material and shape.

Perhaps uses two coils one to pick up the current and another to boost voltage like a joule thief ?

Would help if someone whom better understands the concept could scribble out a rough schematic to illustrate the concept for the slow witted such as myself.