Bicycle lights (Batteryless! No friction!) a simple circuit

[iwico]

This bicycle safety flashing light system is based on
a newly invented electrical generating system, NO
battery needed, No friction on any parts of the
bicycle. No drag. get the energy almost free (at least
on bicycle). Very bright. Standby light.

Details:
https://www.freelights.co.uk

The circuit for this light system is attached with this message

 

[cowboytuna]

what do u mean tumbling magnet?? and sorry im quite confused... :cry:

 

[McGuinn]

Energy In = Energy out.

There will be *reduced* energy loss because this method is more efficient than using a dyno.

 

[mvs sarma]

Hi
normal cycle dynamo will give voltage and wattage at a nominal speed. and the bulb intensity will be enough to see the raod clearly with no external illumination(like under mains failure condition- or on highways and village roads)

this device uses a bright LED ( OK few of them) and capcitors to charge. basically he has cut cut down illumination drastically-- i am pretty sure you cant see the road anymore-- leave alone giving attension to a vehivle from other side.

nowhere i fond exact wattage of the device-- these are analogeous to the shaking torches sold in the market from Chinese and other Asian sources.. they cast amoonlight like light on the loaction--ok for seeing and opening a door lock-- etc--

 

[philba]

to be clear, there may not be mechanical friction but there will still be a resistive force. Something has to create an EMF, it doesn't just spring out of thin air. every time the magnet passes the "generator" there will be a counter force as the coil creates an electro-magnet. I would guess that it feels like a bump each time.

I agree that this thing will not generate very much power.

Frankly, I think a better solution is to use a form of regerative braking to charge a battery.

 

[mvs sarma]

Hi Philba,
thanks for the comment-- i live in INDIA and we had sometime back specially manufatured HUB of rear wheel of a bicycle which incorporated a dynamo- as compared to Sankyo made dynamos which used to land on the type edge and work(of course they always had the advantage of high speed due to ratio of dynamo knob vide tyre edge)

these new hubs did help reduce the friction to some extant-- how ever for purposeful light we require enery- and this light is for our SAFETY-- not for economics of energy --

thanks again

 

[Hero999]

Flashing lights on bicycles are also illegal in some countries. They are here in the UK but no one pays any attention to it.

 

[audioguru]

In most civilized countries bicycle riders use rechargable batteries to power their LED blinking lights at night.

 

[Hero999]

Battery powered LED lights in flashing mode should not be used on the road. Normally most models have a non-flashing setting which should be used by all cyclests. I think the flashing mode can be used by pedestrians but that's all.

 

[Blueteeth]

hi,

I'm not a cyclist, but a few quick comments:
- Been done. A friend of mine did this years ago, not quite as simple cirucit, and he had two magnets on the wheel to charge a large cap. LED's in series to reduce the resistor loss and a cheap regulator. Flashing/OFF/ON switch.

- I'm sure those LED's are bright, but 'mcd' isn't really an indication of light output, just in the 'forward' direction, even so, I don't think it would be bright enough for true safety.

- Of course there will be drag, but i doubt if it would be noticable, and no where near the same as a dynamo.

Bout time this sort of thing was published on a webpage though, its a start for sure. Wonder when supercaps will start replacing batteries in apps like this?

Blueteeth.

 

[Hero999]

The magets on the wheel will form a crude alternator, infact a modern bicycle dynamo isn't really a dynamo, it's an alternator because it produces AC not DC.

 

[audioguru]

Here, cars use low beams at night, except English and Chinese people who drive on our roads at night with only the parking lights on (they are dangerous). We NEVER use parking lights, not even for parking. We have street lights.

Here, some bicycles might have a continuous headlight, but all have a flashing light at the rear. It is much easier to see a blinking light than one that is steady. If you think a dim blinking LED is a car's turn signal then you are drunk (or English?) and shouldn't be on (the wrong side of?) the road.

Here, pedestrians walk on sidewalks. Only drunks (or English and Chinese people?) drive their cars on the sidewalks.

 

[mvs sarma]

The magets on the wheel will form a crude alternator, infact a modern bicycle dynamo isn't really a dynamo, it's an alternator because it produces AC not DC.

Hero999 is Right- it is an alternator-- i should not have used the word dynamo- somehow, it was commercially called a cycle dynamo--

 

[Nigel Goodwin]

Wonder when supercaps will start replacing batteries in apps like this?

It's doubtful they will (except for very limited applications), too expensive and much too small a capacity.

 

[Hero999]

I think old dynamos were real DC dynamos but the brushes probably used to wear out and be susceptable to damage from dirt, so they started using alternators but people carried on calling them dynamos.

 

[Nigel Goodwin]

I think old dynamos were real DC dynamos but the brushes probably used to wear out and be susceptable to damage from dirt, so they started using alternators but people carried on calling them dynamos.

Yes, original ones were dynamos - can't say I've ever heard of problems with them wearing out though?. More likely a question of cost, an alternator is cheaper to make.

 

[Hero999]

Have you ever opened up a bicycle alternator?

They really are cheap and nasty. The stator is a single winding located at the bottom and the poles of pices of mild steel bent around the permanent magnet rotor. They probably have an efficiency of less than 60% due to the eddy loses - the poles aren't laminated. I would rather not have to pedel as hard and pay more for a higher quality alternator.

The only problem I've had with an alternator is the magnet brushin against the poles, I assume this damaged was probably caused by vibration and bulbs can blow if you go too fast.

 

[Nigel Goodwin]

Have you ever opened up a bicycle alternator?

No, back in my bicycle days they were still dynamos