The goal was to make it work for 3V battery applications –I thought this would be easy, but Murphy thought otherwise –apparently the limiting factor is the LM317 voltage regulator. As a result, the 3V ...

The circuit’s built-in power supply has been kept very simple. The single-cell Li-ion battery (BAT) provides a nominal voltage on 3.7 V. The power supply also drives a “luxury” white LED light source ...

Isn’t it always the way? There’s a circuit right out of the textbooks, or even a chip designed to do exactly what you want — almost exactly. It’s 80% perfect for your applic… ...