Power Supplies and Voltage Regulators

A power supply is an electronic device that supplies electric energy to an electrical load.
The primary function of a power supply is to convert electric current from a source to the correct voltage, current, and frequency to power the load.
Types of power supplies include AC power supplies, DC power supplies, linear power supplies, and switching power supplies.
AC power supplies take the input power from a mains supply and convert it to a desired amplitude of AC voltage.
DC power supplies turn an AC voltage into a DC voltage.
Linear power supplies maintain the required output voltage by discarding excess power in the transistor.
Switching power supplies convert the power supply’s output to a high frequency and then rectify and filter it to produce the required output.

A voltage regulator is designed to automatically maintain a constant voltage level.
They may use a simple feed-forward design or may include negative feedback control loops.
They can be designed to regulate one or more AC or DC voltages.
Linear voltage regulators are based on devices that operate in their linear region.
In a linear regulator, the control element dissipates excess power to maintain the desired voltage.
A switching regulator converts the DC input voltage to a switched voltage applied to a power transistor.
The final value of output voltage is derived from the duty cycle of the power switch and is filtered to reduce the high-frequency switching.
The major advantage of switching regulators is their high efficiency as the power transistor acts as a switch, either fully-on or fully off.
Voltage regulators are used in devices like computer power supplies where stability and reliability are critical.

The design and functioning of power supplies and voltage regulators is vital to the distribution and use of electrical power in all types of electronic devices.
They ensure that electrical power is safe and efficient for human use, and adequate to operate the connected device without causing damage or inconvenient operation.
Power supplies and voltage regulators involve complex electrical concepts such as transformers, rectifiers, filters, and amplifiers, making their study crucial for a comprehensive understanding of electrical systems.