Voltage regulators take an input voltage and create a regulated output voltage at a fixed or adjustable level. This automatic regulation of the output voltage level is handled in different ways by different types of voltage regulators.
What is a voltage regulator? How does it work?
The most affordable and often easiest type of voltage regulator to use are linear voltage regulators. Linear regulators are compact and are often used in low voltage, low power systems. Switching regulators are more efficient than linear voltage regulators, but are more difficult to work with and more expensive. Zener diodes are inexpensive and easy to use, but are less efficient than linear regulators.
One of the simplest ways to provide stable voltage for electronics is to use a standard 3-pin linear voltage regulator such as the LM7805. This provides an output of 5 volts and 1 amp with an input of up to 36 volts (depending on the model).
Linear regulators work by adjusting the equivalent series resistance (ESR) of the regulator based on a feedback voltage, effectively becoming a voltage divider circuit. This allows the regulator to output a constant voltage regardless of the current load placed on it, up to its current capacity.
