Electronics stuff

This is a (very) small collection of electronics circuits which may be of use to others. I had to draw up a circuit to show someone so I thought I may as well put it online, which is how this section started...

Hacking a Gameboy camera - making a cheap 128x128 B&W digital camera.
Quick notes on super efficient white LEDs - Usenet post to aus.electronics/alt.energy.homepower
DC switching regulator (Mk I) - rapidly chops input voltage to produce a lower output voltage. More efficient than a linear regulator.
DC switching regulator (Mk II) A simpler and more efficient version of the above. Uses a 78Lxx device as a voltage reference and a comparator.[BROKEN]
DC stepup converter - multiplies input voltage up to 8 times.