Converting 1.5V from AAA cell to 0.8V output


Joined Dec 2, 2017
I've tried a voltage divider with just resistors and about 25% of power is lost as heat. Please excuse my limited knowledge, would a diode be much different? I'm also unfamiliar with common collector circuits outside of knowing they use BJTs, would it be more efficient than a diode and resistor combo?
A simple resistor divider won't work very well because the voltage from the battery changes over time, what you need is a fixed reference voltage.

As far as the power loss...well at those voltages I don't see any escaping this problem.