I would like information on the LED lights that Cory H. talks about in Weather Reports. Thanks,

-- Tess (preparingfortheworst@prayingforthebest.com), September 16, 1999

Answers

here is a list of threads here that have info: http://www.greenspun.com/bboard/q-and-a-fetch-msg.tcl?msg_id=000cTb titled:White LEDs, bulk-purchases, and a webpage of drivers... http://www.greenspun.com/bboard/q-and-a-fetch-msg.tcl?msg_id=001BdR titled: :-) White LED bulk-buy #2 progress update and a few ideas... [Long] NOW for da lynx:

STOP #1

STOP #2

Thanks for asking as I needed to find this stuff for myself since I am ANXIOUSLY watching my mail box for a package from Odd One!

Chuck

-- Chuck, a night driver (rienzoo@en.com), September 17, 1999.

Also try HDS Systems in Tucson, AZ. They manufacture a nifty little 24 LED array with driver and bomb-proof housing, which will run for over 300 hours on one lithium D cell battery. Very pricey, but definitely the best.

Also, C Crane has the two LED flashlight ( 3 AA batts), which is good in a minimalist/econo way.

Godspeed,

-- Pinkrock (aphotonboy@aol.com), September 17, 1999.

You can also make your own LED flashlight. I went to Radio Shack and bought the orange Jumbo LED (Cat no. 276-206) and a replacement bulb for my existing flashlight and a 43 ohm 1/8 watt resistor(assuming a two cell flashlight). Gently break the glass out of the bulb. Use a soldering iron to remove the element. Cut one lead short on the LED and solder the resistor on. Polarity does matter here! Solder the other end of the resistor to the base of the bulb. Solder the other lead of the LED to the bulb case. When you are done the resistor is concealed inside the metal case and at first glance the completed bulb looks like the original. This gives off a reddish light not white. One advantage to this is that you don't have to wait to regain your night vision after you switch off the light. I estimate that a flashlight with this bulb should last 300 hours on one set of batteries. Its not bright enought that I would want to read by it but it is more than enough to walk around at night without tripping on something.

-- Y2KDON (Y2KDON@HOTMAIL.COM), September 17, 1999.

At OddOne's site there is a photo series I did on converting a light bulb using Radio Shack parts.

-- bw (home@puget.sound), September 17, 1999.

Oops, muffed the link.

-- bw (home@puget.sound), September 17, 1999.

Also remember that LEDs will not work in reverse polarity. The long wire is the CATHODE lead which must be connected to the positive voltage. If you're soldering one into a lamp base, the part of the lamp that contacts the positive voltage from the batteries is the tip at the base of the bulb.

Also, if you decreases the value of the resistor from 47 ohms to 20 ohms, you will increase the brightness, but you do run the risk of shortening the life of the LED.

Also, if you opt to "roll your own", be sure to get 1/4 watt resistors, as the larger resistors won't fit into the bulb base. I do have a design, for people with "fat fingers", that allows for the resistor to be put into the battery case, istead of the bulb base. It involves the resistor being soldered to two disks of copper, thusly (with 0= copper disk, R= the resistor, and ---= the resistor leads): 0---R---0. The two disks are folded over, with a cardboard insulator, between them. I would imagine you could use two pennies,if you don't have a source of thin copper, but I haven't tried this. The cardboard disk is cut to the same diameter as the batteries, and sets on top of them, before you screw on the lamp/lense assembly. This also is a good alternative, if you're an electronics hobbyist, and all you have laying around are 1/2 watt or larger of the correct value for the resistor.(If this isn't clear, feel free to e-mail me - I'm only on my first cup of coffee, and am not completely coherent yet.)

-- Bokonon (bok0non@my-Deja.com), September 17, 1999.

OddOne in da hauuuuuuuuse! (Sorry, couldn't resist. [grin])

Since I seem to have become a pseudo-expert in white LEDs (I've only started manufacturing white LED lighting systems now and run an entire website about them as Chuck and bw mentioned, and Cory participated in my first bulk-buy which is how he got the LEDs you mentioned) perhaps I could be of some help. If you'd like, feel free to E-mail me at my posted address (which is quite real) with whatever Qs you have and I'll be happy to fire off the corresponding As. I have a -LOT- of info on white LEDs, using them, caring for devices that use them, good products out there that use them, making your own devices, sources, etc. etc. etc.

And as for the folks (ahem, Chuck?) that are waiting for their LEDs from the second bulk-buy, the order goes off today for the BB. (Hadta wait for a few checks to clear.) Expect an announcement to that effect this afternoon via E-mail. :-)

The guy Nichia (a white LED manufacturer, BTW) loves to hate...

-- OddOne (mocklamer_1999@yahoo.com), September 17, 1999.

Hey guys? Where can a electronics virgin get a quick education in said subject? I like to tinker, might be fun to add a new area of tinkerability.

Thanks.

-- Uncle Deedah (unkeed@yahoo.com), September 17, 1999.

Unk Deeds,

Wish I could give you an easy source, but I just picked up bits and pieces, here and there. I found a few old Radio Shack project books, at yard sales, took a few books out of the library, picked up tips from other people, etc. All of this was over an enourmous period of time.

The two quick tips I can give you are: 1)Don't bother looking for a good primer source, on the web. If it exists, it's well hidden. I've searched a zillion times for sites that give tips and techniques and/or schematics, and all I keep coming up with are sites that sell components. Maybe someone else on here knows of a good site. 2) The most basic and critical skill, in electronics, is proper use of a soldering iron. Components are very easy to destroy, from excess heat. Always let your iron heat up completely. Always make sure the surface is clean. Always use soldering flux, to help the molten solder flow into the connection easier. Always use a heat sink on the lead you are soldering, between the iron and the component (a heat sink is a little clamp, usually made of aluminum, that draws the heat away from the component. There are other types of heat sinks, but for soldering work, the spring clamp type are most common).

Get yourself some small guage wire and practice soldering techniques before you try to actually make anything (I know...this is the boring part, but it really is important. I didn't do this, when I first started, and lost mucho dinero, in fried components). After that, pick out a simple project, to get started with. If you want your LED Flashlight to function as a warning flasher, or if you really want to just annoy the hell out of family members, an LED flasher circuit is cheap and easy, and a good place to start.

If there's anything more specific you'd like to know, feel free to e-mail me.

-- Bokonon (bok0non@my-Deja.com), September 17, 1999.

Hey Unka Deedah...

Bokonon is right, the web is not the place to go for basic intro-into- electronics, but I -do- know of a book that works... It worked for me anyway. It's "Getting Started in Electronics" by Forrest Mims III. Radio Slack carries it for five bucks. It'll give you enough of a primer in electronics to be able to launch into more detailed research via other channels (web, etc.) This was the book I learned rudimentary electronics with and makes a nice springboard.

Hope that helps! :-)

That guy that can build a mean Cockroft-Walton bridge, known as...

-- OddOne (mocklamer_1999@yahoo.com), September 17, 1999.

Great thread, y'all.

Hey, OddOne, glad to hear that the order's on its way to Nichia. You mean everyone didn't send you strange little pieces of greenish-yellowish paper courtesy the USPS? Gad...

-- Mac (sneak@lurk.hid), September 17, 1999.

Many thanks! (so much for the idea that doomers are heartless bastards)

-- Uncle Deedah (unkeed@yahoo.com), September 17, 1999.