New Power Source

The Siva Atom. http://sivacycle.com

Weighing in at only 300 grams, an email to the creators reveals that you don't get access to the raw ac output, but you can get up to 5W, from 5V dc at 1000mA. That's getting two thirds again what I can get from a near 1kg 3W hub dynamo. They reckon 10mph for 5W output, with 2.5W at 6 mph.

Has anyone got one, and what would be the best way to use it? (I'm thinking the LED ccts here)

I thought the integrated battery with it would do for a standlight, so I'd actually need a timing circuit to cut it off once I stop for more than, say, 4 mins.

their kickstarter page says it can generate 4.5 watts at 15mph, and can output 5v at 0.5A.
http://www.kickstarter.com/projects/332999904/the-siva-cycle-atom-powering-your-life-one-pedal-a

You can probably get at least 4.5 watts from your hub dynamo. I'm getting 6 watts from mine when traveling faster than 12mph or so. It does require that the dynamo not have a built-in voltage limiter as well as the ability to wire two headlights in series (or make your own headlight that effectively wires two headlights in series). It's a well established method going back to the days of incandescent headlights. It does reduce the power available at low speeds, though, so there is usually a way to short out one of the headlights at low speeds.

First, the task is energy conversion rather than finding a 'new power source'. I know it just seems like semantics, but I think it's an important issue. The power source remains the same - your legs. What's at issue is efficient energy conversions - a process involving mechanics and energy flows and (on a bike) some fairly unique environmental considerations and vulnerabilities.

IMHO this Siva device doesn't seem to provide anything really new or worthwhile. There have been so many of these multi cog/pully/roller battery-charging devices over the last decade or two. They come and go regularly it seems without having much impact. I recall products made by Union, Fer, Ecolight etc. Probably many others.

What seems to persist in the field of generator lighting are those products which provide:
- mechanical strength (means minimal bearings and moving parts)
- best weather integrity (seals etc)
- adequate and efficient lighting (best available light conversion).

I reckon this is why generator hubs have been so successful! And it seems to me that this whole notion of 'powering your devices via pedaling' is - for most people - a solution looking for a problem. Sure, it may be an issue for those touring of located in remote areas. But for most of us it's a non-issue. And there are already many, apparently far more robust devices that provide these energy storage and 'device powering' functions while also offering better weather protection and flexibility etc. B&M make one as do several other major manufacturers, all without the use of cogs and pulleys! I cannot think of any worse place to locate complex electronics that down by the rear axle - the dirtiest and most exposed part of the bike! For me it's a non-starter I'm afraid.

Sam.

There had been geared plastic dynamo contraptions in the past, including a few mounted over the rear axle. Hmm..., they lacked efficiency, durability and lasting power in the market, for those over the rear axle.