Wow – its only been a couple of days since I posted the schematic and already a question. Basically its asking what voltage regulators am I using.

My input power comes from a 7.4V pack of lipo batteries, usually about 300mAh capacity, I need 5V for my motor encoders, and 3.3V for the rest of the circuit.

The current load is fairly high, it bursts up towards 1A when the sensors are going (roughly 1/10 duty something is on). So fairly high current requirements.  I also need something with a reasonable dropout , as I can run the batteries down to 6V – so a 1V dropout for the 5V line.

Putting my ‘It would be nice to get something for free’ hat on I turned to samples! I use TI for most of my sampling needs, and the REG104 series looked pretty good. Cheap linear low drop out regulators that can take some throwing around and come in fairly accessible packages.

http://focus.ti.com/docs/prod/folders/print/reg104-a.html

They don’t get too hot when running, and only require a few external parts. So meet all my requirements, so much so I always have a pile of then on standby for random project usage.