On Tue, 07 Mar 2017 20:00:47 +0700, John B.
wrote:

On Mon, 06 Mar 2017 20:10:21 -0800, Jeff Liebermann
wrote:

On Mon, 6 Mar 2017 16:57:41 +1100, James
wrote:

What if I don't want to play with batteries?

Then play with calcium carbide (produces acetylene gas) instead:
https://www.google.com/search?q=acetylene+bicycle+lamp&tbm=isch

Ahem! I don't think you should suggest acetylene gas devices to some
of the folks here. After all the safe limit for acetylene gas is 15
psi, above which it tends to go BOOM! :-)

I once found a patent for an acetylene lantern design that used the
heated gas pressure from the burning acetylene to pressurize a reed
and thus act as a horn. I don't recall if it had a built in red tail
light.

What keeps an acetylene lantern from blowing up and ruining a ride is
that the drip of water into the calcium carbide chamber is regulated
by the back pressure produced by the reaction. No water means no gas
is produced. It's a gravity fed affair, that's quite reliable and
should never raise the internal pressure anywhere near 15 psig.

(but maybe if you wear a helmet and have a bright light... :-)

The light isn't for me. It's for James who wants an alternative to
changing batteries. I solved my lighting problem long ago:
http://802.11junk.com/jeffl/pics/bicycles/slides/bicycle-flashlight.html

The big problem with an acetylene bicycle lantern is that a typical
lantern only delivers about 30 to 50 lumens (my measurements).

If you need a project, build an acetylene lamp that screws into an
aluminum water bottle.
http://www.4bobandbob.com/pages/pics/PremierDia.gif

--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558