A Non-friction bicycle lights generator (dynamo)

Well, you don't get something for nothing. No friction, but there will be a very small tug each time the magnet passes the coil. Won't be noticeable or even detectable without test instruments, or make any difference to the feel of the bike, but it is non-zero. :)

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Now for the negative! Technically, as UK law stands at the moment, the use of an LED light as a sole means of lighting is illegal because the law specifically states the use of a "filament bulb". Similarly, the law precludes the display of a flashing light on anything other than emergency vehicles. The British Standard (BS6102 Pt3) which includes lighting for bicycles was updated a few years ago to allow LEDs but with certain stipulations (they must be visible from the same range of directions as a filament bulb lamp and they must not flash). The law is only just about to be updated to legalise their use.

1. snipped-for-privacy@yahoo.com Nov 10, 9:49 am show options

Newsgroups: sci.electronics.repair From: snipped-for-privacy@yahoo.com - Find messages by this author Date: 10 Nov 2005 09:49:32 -0800 Local: Thurs, Nov 10 2005 9:49 am Subject: A Non-friction bicycle lights generator (dynamo) Reply | Reply to Author | Forward | Print | Individual Message | Show original | Report Abuse

Back in the 50's-60"s, some Raliegh, probably British import, bikes had a dynamo built into the hub of the front wheel. They would have been far superior to the friction clamp-on jobs we had to use on our paper routes. I wonder why that design was dropped. I had a used Raliegh

3-speed for a while, but it had the drum brakes instead of the dynamo. They were not good brakes.

John Kogel

Just about every London Transport bus has LED rear lights.

--
*Nostalgia isn't what is used to be.

    Dave Plowman        dave@davenoise.co.uk           London SW
                  To e-mail, change noise into sound.

I was only quoting but 1 thing the rear lights on a bus do not flash and you forgot motor bikes BMW's Mercedes army lorries ETC

My British bike ( which was a Raleigh ) that I had when I was a kid in the

60's, used a hub dynamo on the front wheel, and a Sturmy-Archer three speed gear hub on the rear wheel - worked by a twist-grip, no less, rather than the old finger lever !! A lot of my mates had bikes with the old friction " bottle " dynamos on them, and I couldn't believe how much pedal effort it used to take to turn them, against how easy mine was. There was no difference that I could detect, lights on or off. but I guess that there must have been a little.

I also remember that some bikes - particularly those used by the coppers - had a sort of cylinder fixed to the vertical frame section under the saddle. This contained rechargeable batteries of some description. I guess they were D sized cells. When you stopped pedalling, the lights continued to be powered by these cells.

It occurs to me, on reflection, that rather than dynamos, these generators were actually alternators, in which case, there must have been a rectifier of some description, ahead of the battery pack. Back in the 60's, this would probably have had to have ben a selenium plate-stack type ?

Arfa

I'll bet the British law specifically stated "filament bulb" was because they wanted to end the use of lights that burned flammable gas and other not-so-safe materials in the early days.