Improving a book light

I love to read.  Often, I use a portable light that clips onto the book.  It works OK, but two things bugged me about it.  First, it required four AA batteries.  Second, it used an incandescent bulb that is bright, but which produced glare and hot spots on the page.

Original bottom view

I had been experimenting with a simple circuit called a Joule Thief.  This circuit boosts a DC voltage to a higher voltage.  It’s is easy to make with easy to obtain parts.  The Web is full of plans for these devices.  The advantage for this project, is that such a circuit can drive a bright white LED from a single 1.5 Volt battery.  I figured that I could easily fit the circuitry and a single AAA battery into the battery compartment of the book light.  This would save batteries and provide a more even light across the page of a book.

Joule Thief

I replaced the incandescent bulb with a bright white LED that I encased in aquarium sealant inside of a short length of clear plastic tubing.  This helped to diffuse the light along the approximately two inches of tubing that the LED was attached to.  Here’s the final assembly and it’s use.

Ready to use

Modified lamp in use