After the output voltage (1.25V-26V arbitrary value) is determined independent of input voltage (3.5V-28V input any value) the module automatically buck. Adapter solar panels. New masterpiece. Wide voltage Buck-boost module LM2577S + LM2596S dual chip Boost mode: Input 3.5-28V output 1.25V-26V. The output voltage independent of input voltage (3.5V-28V Input Output 1.25V-26V any value to any value). Buck mode: Maximum input current 3A 3A maximum output. Rated input 1A 1A output Note: Due to lower the switching frequency of the input current is large inductance will be some high-frequency noise does not affect use .