Is it possible to change voltage without consuming power?
I have a 5V Arduino circuit that makes use of a wireless chip (NRF24L01) that runs on 3.3V. My current approach to get 3.3V out of a 5V source is a voltage divider using a two resistors. It is cheap and very easy to setup. The disadvantage is that the consumption over the remaining 5V - 3.3V = 1.7V is lost / wasted. I run the circuit on an AA battery so power consumption has to be as low as possible.
Now I am looking for a way to not loose any power in the process of getting a 3.3V out of 5V. One approach would be to use a DC buck step down converter. It uses very little power to do so, but it also is more expensive than the voltage divider using resistors. There is also the possiblity to use an AMS1117, but I have no experience with that.
Is there a cheap and power saving solution for getting 3.3V out of 5V?