mmp one cell question

[BrianG]

You can build your own boost regulator with the LM2577 IC. Pretty simple base circuit with minimal external parts, and ratings up to 3A and input voltage around 3.5v. I'm sure there are similar devices out there, that was a quick search. You might want to look at LED driver circuits for ideas; there are many circuits that will boost from a single AA cell to drive an LED. It won't be adequate for servo duty, but could give you ideas. Also look into the "joule thief" circuit for ideas.