I recently reviewed the Color Night Joule Thief by The LED Artist, and tonight I built the original Night Joule Thief. It works just like the color version, except that it uses two white LEDs instead of a single color-changing LED, and has slightly fewer components. Unlike the color version, I didn’t run into any problem with the PCB layout; everything fit with no risk of any short circuits. Assembly is easy and well-suited for a beginner.
Light output is very good using a fairly new battery. I tried it in my bedroom and it provides enough light to keep me from stubbing my toes on the bed posts after dark. With that said though, I wish the output was spread out more, it’s very narrowly focused. This could be adjusted to some degree by soldering the LEDs so they point at different angles. Another possible solution is using LEDs with a wider output beam. I purchased two kits, so I may try doing something like this with the other. Other possible modifications which are discussed on the related Instructables page include using a switch instead of a photoresistor to turn the LEDs on and off, and using alternative battery clips to allow for C, D and other size 1.5v batteries.
Overall, this is an excellent kit, perfect for beginning electronics enthusiasts learning to solder as well as experienced hobbyists looking for a simple circuit to build that offers some room for customization. It’s available for under $11 from The LED Artist.