The compact (0.4″ × 0.6″) D24V3ALV switching step-down (or buck) voltage regulator takes an input voltage between 4.5 V and 42 V and efficiently reduces it to a lower, user-adjustable voltage. It has a output voltage range of 2.5 V to 7.5 V and a maximum output current of 300mA. The pins have a 0.1″ spacing, making this board compatible with standard solderless breadboards and perfboards.
These adjustable buck (step-down) voltage regulators generate lower, user-adjustable output voltages from a wide input voltage range of 4.5 to 42 V. They are switching regulators (also called switched-mode power supplies (SMPS) or DC-to-DC converters) and have a typical efficiency of 80%, which is much more efficient than linear voltage regulators, especially when the difference between the input and output voltage is large. The output voltage is set using the board’s trimmer potentiometer, with the two D24VxALV versions having an available range of approximately 2.5 V to 7.5 V and the two D24VxAHV models having an available range of approximately 4 V to 25 V.
More technical information at Pololu.