The Story (skipable) :
I was a little disappointed with the battery life (only 60 days) of my previous award winning (lol) Instructable (The EggLight) so when my girlfriend asked me to build her a wall USB charger for her iPOD I decided to merge a night light into it =] and get rid of the problem
What is really cool about this project is that it uses my new high brightness LEDs that I ordered straight from china =) and as you can see from the picture they work great for backlighting purposes...
The Final product :
A wall outlet charger for USB devices (500mA @ 5v ) with a built in smooth blue night light! (yes I do like blue, and I do like nightlights )
+Charges USB devices (tested with an Ipod Mini, an Ipod nano and my sister's Ipod Video),
+Works on 127 and 220 VAC outlets (50Hz and 60Hz ) lol... since nokia did this part ;-)
'V2. Dimmed light
+Instructable released !!!
Step 1: What You'll Need:
+1x. Cheap Bedside battery powered Light
I bought this for 2$... and it comes with a nice switch =P
+1x. Female USB connector :
If you plan to charge USB stuff.. you better have a way of connecting it to your charger =]
+1x. 5v to 7v power supply :
I used an old nokia charger ( 800mA @ 5,7v ) I had lying around...
You can also DIY (see ElectricJ's great instructable ( https://www.instructables.com/member/ElectricJ/ ) ) just make sure your's will be able to supply at least 520mA
+1x. "Straw hat" LED ( http://www.hebeiltd.com.cn/?p=leds.4.8mm ) :
This is excellent for backlighting purposes , it's viewing angle is HUGE !
of course you can use whatever LED you have available =]
+1x. 10K potentiometer , two 100ohm resistors
Step 2: Modding the Original Light (Clearing Up Space)
First things first... We need to completely destroy the battery container so that it will make room for the power supply, I used a saw to completely clear the "top" of it off (look at the pictures)
Step 3: Playing With Your New LEDs =]
Test you leds with a bench power supply and a potentiometer =] see if the effect is good enough for you...
I decided to follow the manufacturer specs and keep it at less than 30mA =] ... A 200ohm resistance will do...
v2. added a potentiometer in series with this resistance
Step 4: Modding the Original Light (Adding the Plug and USB)
If you're using an old cellphone power supply like me , and you WERE CAREFUL during the disassembly you can still use the original plug, with a soldering Iron , or a Heated knife (or even a small drill) make two holes for the AC wires to come into the case, pass the wires and glue the plug together with the rest of the case (I also used some insulating tape since this is the wall side)
Using the same Heated knife method , open a hole in the side of the case, it should be slightly smaller than the USB female plug (barely fitting)
+Uses an optional potentiometer that can be seen on one of the pictures
+Has the Instructable Sticker! that just arrived as part of my valentine's day prize! =D Thanks Instructables!
Step 5: The Circuit
+If you're using a power supply that is slightly over 5V than you'll NEED a regulator...
(there are alternatives... but... since a 7805 costs like... ermm about 30cents a piece... I'm sticking with it)
+The potentiometer is optional, but you should increase a bit the resistance if you decide to ignore it... (otherwise your girlfriend, or whoever uses this, might not get any sleep at night)
The circuit schematics is shown in the picture bellow, To get the image on it's original size, click the "i" on the top-left corner of it
+I used one of my standard breadboard-like perfboard
always double check the pinout (see picture)
Pin 1 = Vcc
Pin 4 = Gnd
Step 6: Fitting in the Case
With a bit of luck you'll be able to fit the whole thing back in it's original case and by luck I mean LOTS of Hot Glue, Super Glue and Insulating Tape =)
Step 7: You Finished It!
Congrats, the charger is completed... Plug it in an outlet ,turn it on, double check the USB pinout with a multimeter =] and Start charging your USB devices... with style...