I have always had Nightlights in my 2 bathrooms since they don't have windows. I've been using the standard Christmas Light style of Nightlight until last month. I was changing the burned out Christmas lights about 3 times a year, and they are fairly expensive so I decided to go to LEDs. I looked at several ways of powering the LEDs straight off the 120vac line and didn't really like the methods very much and decided to make the nightlights out of Wallwart transformers. I have a huge box full of these, a wide variety.
I'm using 2 tricks with the LEDs, flatten or cut the tops off so they throw a wider beam, then use White & Red LEDs together to improve the light color. I like twice as many White as Red and love the pleasant color output. There are red LEDs in the picture but the whites overpower them.
I tried to select small sized wallwarts for use as a nightlight, and 12vdc power supplies so I could string several LEDs together. I then measured the actual voltage that it put out since wallwart voltages vary wildly from their labeled ratings. I then went to this LED Array Wizard page and calculated my dropping resister sizes.
http://led.linear1.org/led.wiz
Don't overpower your LEDs on a nightlight or they won't last a long time.
It was a little difficult to tack all the small bits together with a soldering iron. I soldered 3 or 4 LEDs into a string with a 1/4watt dropping resister. Using 3 to 5 LED strings on each nightlight. I cut the wire cumming out of the wallwart to about 1.5 inches and stripped the wires down to within a 1/4 inch of the strain relief then Tinned each wire thoroughly. The wires can then be bent into a "U" shape that you can solder the premade LED strings between. I got some black paint and painted any exposed wiring so you can't see it against the black plastic housing. The LED array can be bent around a little bit so you can aim them in most any direction.
If anyone messes around with a Wallwart be careful not to short the output wires, there can often be an internal fuse that once blown, it is almost impossible to change.
I used my Kill-a-Watt meter and measured my Christmas lights at 4 watts. The LED nightlights showed 1 watt. The unloaded wallwarts measured Zero watt. The best looking one is 12 white and 6 red. Plus the best part, I never need to change the bulb anymore.
W o o f -={(
