View Full Version : Lets build with led lights

01-26-2010, 08:30 PM
Hi all,

there is a growing interest on the LED projects among DIY people all over the world.
LEDs are simple and are replacing the common lights very fast.

What can I make ?
Desk lamp with torch
Bike Lamp (cycle),Spotlight
Mood light , Tube replacements.. and mony more

Why ?
There is very less number of quality readymade lights with LEDs in INDIA.
+ learning + saving of electric bill .

technical info on the ICs etc ->http://www.e-f-w.com/community/content.php?cid=lighting_most-recent
many LED projects> www.instructibles.com
Mainly torch and LED diy > http://www.candlepowerforums.com

01-26-2010, 08:31 PM
My story :
I bought a china made LED torch cum table lamp. Costed 110Rs :)
Charges well gives 8Hour backup minimum(did not check when it goes off) from a 6hour charge

What is special here is it is a torch with a flip 6ultrabright LED panel.The panel tilts at 15degrees , so you can point the LED sets all directions... that is too much the price of 1 cup coffee in some places .Panel can be hidden when used as torch.
But there is a problem!

The table light /torch loses the intensity after 3hours to 60%.
There must be a way to keep intensity same. I needed a constant current source at least 0.5A.

I searched on net and got (LED driver) : http://www.candlepowerforums.com/vb/showthread.php?t=236260
And I know about joule thief circuit ->simple 1 or 2 transistor circuit increases the voltage.
Here is joule thief:

(i assume battery is 6v )
Plan is :
battery(6v)>joule thief(9v)>LED driver>LEDs

smooth white light till battery loses the charge (if backup become 6Hrs , fine na!)