Date:         Tue, 8 Aug 2006 00:51:36 -0500
Reply-To:     joel walker <jwalker17@EARTHLINK.NET>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         joel walker <jwalker17@EARTHLINK.NET>
Subject:      Re: them led lights
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... speaking of which, there is a small one-page how-to in the august
2006 issue of popular science (at your local newstands right now)
about making your own "led candles".
their cost, $3.33 and 15 minutes of your time (after you've gathered
all the parts).
supposed to last up to 36 hours on one 9v battery.

parts list ...
2 resistors:
   1 each 100-ohm
   1 each 220-ohm.
(doesn't say, but i'd imagine 1/4 watt rating would be fine).
cost about $0.19 each. radio shack.

1 9volt battery. $1. seems like they cost more than that around here.

1 9volt battery CLIP. $0.45. radio shack. this is the black plastic
   thingie with the two metal grippers that attach to the 9v battery,
   and has two wires coming out of the black plastic.

2 white 10mm, 18,000mcd LEDs. $0.75 each. might have to order these.
   he used alan-parekh.vstore.ca  claims they are the super-bright
kind.

? wire connectors (?), optional. $0.15
   ah .. "white rubber sleeves" known as wire connectors.
   says "soldering heat can ruin the LEDs".

the circuit is set up thusly ...

......(A)........resistor........(A)......
.        ........resistor........        .
.                                        .
.                                        .
.+......LED 1                            .
        LED 1                            .
.-......LED 1                            .
.(B)                                     .
.+......LED 2                            .
        LED 2                            .
.-......LED 2                            .
.                                        .
.(C)                                     .
.                                        .
.-.....(shows red wire)...battery clip   .
                          battery clip   .
.+.....(shows black wire).battery clip   .
.                                        .
..........................................

so the resistors are in parallel. and notice there's no on-off switch
... apparently you're supposed to just clip it to the battery and let
it shine.  one would suppose a small switch might run a whole nuther
dollar? :) but it would be the box to put all this in that would run
the price up to just about the same cost as those 3-led store-bought
kind.

but if you're in the mood to make it yourself, or build something
semi-permanent into the camper interior, this might be a good project
for you.
anybody want to figure out what resistors would be needed if you
wanted to run this off the house/car battery in the bus??

have fun! :)
unca joel