On Wed, 8 Mar 2017 09:45:43 -0800, sms
wrote:
On 3/6/2017 9:22 AM, Jeff Liebermann wrote:
Kinda looks like all of them will sorta deliver 2.5 watts before the
core saturates (to provide some level of voltage regulation). Further
down the page is a "Low Speed Power" graph, which shows that most can
produce 2.0-2.5 watts at 10km/hr. One could assume that the dynamo
will deliver 4.0 watts, but that would require buying one of the few
better (hub) dynamos listed, and riding at 25-30km/hr (15-19mph).
If I were designing or sizing a lighting system suitable for my slow
style of "cruising", I would use the worst case 10km/hr (6mph) and 2.0
watt figures.
You've touched on one of the reasons why dynamo lights haven't caught on
in the U.S..
Touched? I was trying to sledge hammer the reason. Basically, one
design is not going to make everyone happy. Some riders can easily
maintain the speeds necessary to utilize the dynamo at well above it's
rated capacity. Others, like me, can barely make it spin.
I'll spare you my rant on the benefits of a hybrid battery + dynamo
system.
I wish that it were possible for inexpensive, dynamo powered lights to
provide adequate illumination for commuting, but it isn't. I recognize
that few people can afford nearly $500 for a hub dynamo wheel and a
SuperNova E3 Triple 2. For commuting, where there is no problem
charging batteries every night, a high power LED set-up is more
economical and provides better illumination. It's hard enough getting
people to spend even $25 on a bicycle light, getting them fork out $500
for a dynamo wheel and a decent dynamo light would be damn near impossible.
So how duz it cost to build one dynamo wheel and headlight?
Prices are my guess(tm) based on experience and random googling.
Shimano Nexus series hubs can be found for about $70.
Wheelsmith spokes are about $0.50/ea or 26 for $18.
Generic rim for $35.
Tire, tube, and rim tape for $20.
B&M Lumotec LUXOS B for $64.
Wiring for free.
====================================
total = $207
While $207 is not cheap, it's much less than your $500 estimate.
--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060
http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558