In this I will show you how to make a solar rechargeable automatic led night light. I made mine for outside use but hey you could do whatever with yours! :)
How did this idea come about? first I have been meaning to get some sort of light fixture in our back yard, I was going to install an outside light but that fell short once I saw the ratherr poor wiring in the garage. Now the light I wanted shouldnt be so bright but just enough light to see the table and surroundings so I decided to use leds, so I finaly came up with this product. Its a 2l bottle turned into a table light. but its more than that, Its solar rechargeable, and turns on by its own at night. I used a 3.7v lithium ion battery and a charge controller to properly charge the battery, an npn and a LDR circuit. now if you are not familiar with these types of batteries and how dangerous they can be then I recommend using normal batteries such as 4 double As, rechargeable of course. If you charge lithium ions inproperly it could end bad. That being said, do this at your own risk.
before starting give the video a watch :)
it lights at night and charges in the day time
Step 1: Things Needed.
5 white leds
5 volt power supply (needs to be rechargeable ((4xAA batteries should work just fine)) )
If you change the value of the resistor you can alter the sensitivity of the on/off action. dont change the value by alot because you could fry the npn.
Step 2: Schematics.
the first picture is the npn/ldr circuit. If you feel your leds are too bright or even slightly blue you can add an optional resistor where I pointed it out in the picture. A ten ohm should do the trick.
The second picture is the battery charger using a solar panel. pretty easy stuff.
Step 3: Moving It to the Bottle Part 1
Step 4: Moving to the Bottle Part 2
The npn is hidden behind the panel. forgot to take a pic of it.