Has anybody tried the shimano hub with the same 12V lighting? I suspect it may well work. (I know it happily delivers > 8V).
I've been doing a lot of dynamo measurements recently, and can report that electrically the Shimano HB-NX30 and Schmidt are very similar. The Schmidt will produce a higher maximum power for a given output frequency, but the Shimano has more poles (14 against the Schmidt's 12, unless I've miscounted, which is entirely possible) so at a given road speed they're almost the same.
Note that getting more than 6V out of either of these two relies on drawing less than 500mA from the dynamo. I was going to try two 3W halogen bulbs in series on my test rig just to see what really happens and how efficiently the bulbs are run, but one of my 3W bulbs has failed. Must get round to buying another...
Shimano hub dynamos use 28 magnetic poles, Schmidt hub dynamos contain 26 individual magnets.
Aha! So I had miscounted. Thanks for the correction. I haven't actually taken apart the dynamos to count the physical features inside, and had relied on counting the magnetic 'notches' during rotation, which was surprisingly difficult to do accurately. The difference in performance between the Schmidt and the Shimano is a little greater than I had thought, then.
Quoted message said:
Quoted message said:
Note that getting more than 6V out of either of these two relies on drawing less than 500mA from the dynamo.
No. Both will deliver 6V-500mA at 10 to 15 mph without problem.
Indeed, that's true. I think I phrased it badly: a load which draws 500mA at 6V will get hardly more than 6V (well, maybe up to 8V) no matter how fast the bicycle is travelling, due to the characteristics of the dynamo. To get substantially more than 6V (such as 12V for two lamps in series) requires drawing a current less than 500mA, at least according to the measurements I've made on my samples here.
"Zog The Undeniable" <[email hidden]> wrote in message news:41a8bcae.0@entanet...
Quoted message said:
Mark Burch wrote:
Dynamo (B&M 6 is cheap; Shimano dynamo hub moderate; Schmidt dynamo hub expensive) plus a Schmidt E6 front lamp. Use a Cateye TL-AU100BS or TL-LD260BS at the rear.
Thank you very much to everybody for all the suggestions.
Check out www.bicyclesafetylight.com These are real awesome lights , makes one visible from alot of angles.
Mark Burch said:
What lights would you recommend for a road bike?
I'm thinking of riding long distances at night on major and minor roads and possibly taking part in a long distance event that includes riding through most or all of the night. They would only be used occationally. Weight, reliability and brightness are more important for my needs than economy.
