by Xin Feng [01/01/04]
Are you tired of changing the bulb every month or so? Follow this article, you can make a bath room light that lasts forever and consumes almost no power.
The circuit is very simple with just three parts available from your local Radio Shack.
The 10K resistor must be 1/4W or higher power ratings. As 1/8 W is easier to find, you can use two 4.7K resistors (serial them) like what I did. Note that the resistor (s) run hot; don't touch them!
If you want it to be brighter, reduce the resistance from 10K to 4.7K, or even down to 2.2K. Don't go any lower than 2.2K, or you'll burn the LED! Super bright LEDs are very expensive, about $5. But you may try a normal one first and find it bright enough. If you live in Asia, where voltage is 220V, then you must double the resistance.
You need a solder gun. If you don't have one yet, I highly recommend the 15W iron from Radio Shack for $7. This is the best iron - 15W is just right for about everything and its replacement tip is only $.99. With such an iron, you can do any electronics!
Open your night light and remove the bulb. You'll see two metals. Solder the resistor and the diode to these metals and solder the LED to them. Ref to this picture and the above circuit. That's it. If it does not light on, solder the LED the other way.
If you don't like this DIY fun, you can simply buy such a night light from Wal-Mart. The recommended one is the Leviton LED Guide Light (No. 49568-BLU). It is the cheapest ($1.8) and meanwhile has the best art looking (see below picture). The one to avoid is the "elumina dimmable" for $8 - what a perfect example of wasting resource to make a simple thing full of foolish ideas human can ever come up with. It has KidGaurd, which guards nothing but makes the light (heavy and bulk) tend to drop off wall. It has 10 brightness settings, but I see no difference from the lowest to the highest and light life is reduced from 5 years down to 1 year at the highest setting. It has daytime auto off, but what's the point to turn off a $1.8 light that lasts for 5 years and consumes less than 5KWH for an entire year (most American families consume more than 500KWH every month)?
Warning: do this on your own risk! I'm not responsible for any electric shock and burn.
Copyright © 2005
Xin Feng Company