On Tue, 07 Mar 2017 10:38:38 -0800, Jeff Liebermann
wrote:

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.

Well, yes, that sounds like a very good idea, but.... Over here you
can still buy an "acetylene generator" used to provide acetylene gas
for a welding torch. These use the same system "no water, no gas" that
the lamps do. But unfortunately over years of use they get rusty,
dusty, corroded or just clogged up and every once in a while they do
explode. Usually with loss of life.

(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


:-} I solvd my problems using a much simpler solution... don't ride at night :-{


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

Don't need a project. But back when I was shooting on A.F. pistol
teams we used "carbide lamps" to blacken the sights. Very simple
lights with a canister for the carbide and a igniter incorporated in
the reflector that you could flick with your thumb. Spit in the
carbide receptacle, hold your hand over the reflector for a second or
two and flick the igniter. POP (sometimes BANG) and you had a nice
"rich" flame to blacken the sights.

Quite a bright light too. I've used one to look for things in dark
corners and they seem to give off sufficient light. Much better than
my old Japanese bike with the bottle generator and the incandescent
light bulb anyway. And, of course, you didn't have to pedal them to
have lights :-)
--
Cheers,

John B.