"Fred McKenzie" wrote in message
...
In article ,
PeterD wrote:

On Sun, 14 Sep 2008 17:52:58 +0000 (UTC),
wrote:

THe bulb which Radio Shack sells as "standard flashlight bulb"

There is no such thing as a 'Standard Flashlight Bulb'. Flashlight
bulbs are typically rated based on the number of cells (batteries) in
the flashlight, two, three, four, five, for example.


I realised too late it is not E5

Is it E7? I want LED versions

I want one for my bike generator but I have many flashlights


Peter & VJP-

I agree that there is no standard. In addition to the number of cells,
bulbs are often "prefocused" while some are not, and may have plain,
screw-in or bayonet bases.

I found a Sears Craftsman LED bulb, that is supposed to work as a
replacement for prefocused incandescent bulbs in flashlights with one to
five cells (1.5 to 8 volts). It is their stock number 34-93044,
"Variable Power L.E.D. Upgrade".

I tried it in an old flashlight with two C-cells. It was brighter than
the old bulb, but does not compare to a good 1-Watt or 3-Watt LED
flashlight. In addition, it costs almost as much as one of those.

You may or may not be able to use one of these with a bicycle generator.
My generator produces alternating current. I could only use a half-wave
rectifier to convert its output to DC, since one side of both the
generator and the bulb are connected to the frame of the bike.

Fred

The latest issue of Elektor magazine contains a very good article on exactly
that - using a LED to replace an incandescent bulb in an ac driven pushbike
lamp. However, it should be noted that some countries apparently do not
allow the 'upgrade' from bulb to LED.

Arfa