LM317 DC-DC Adjustable Voltage Regulator Power Supply Module

Fixed regulators like the 7805 or 7812 only ever output their one labeled voltage, but the LM317 chip at the heart of this module is adjustable, with its output voltage set by a simple resistor divider, here replaced with a convenient onboard potentiometer that can be turned to dial in whatever voltage a project needs within the chip's working range. That flexibility makes it a handy bench-style regulator for prototyping, where the exact supply voltage a new circuit needs isn't settled yet, or for powering components that need a voltage outside the usual fixed-regulator options. Screw terminals or clearly marked input/output pads make it simple to wire into a breadboard setup without needing to calculate custom resistor values by hand.