An electronic device which supplies electrical energy to a load. Can be AC or DC input. Typically DC output.
The term "power supply" is extremely broad, and covers a large variety of devices.
Some examples of common power supplies:
- AC adapters, which convert AC from the mains to low-power DC loads (commonly referred to as 'wall-warts')
- ATX PC power supplies, which convert AC from the mains to several regulated DC outputs to power computers and their peripherals
- battery chargers, which vary the output voltage and current to safely charge batteries
- inverters, which convert DC into mains-equivalent AC to power devices usually connected to the mains
- DC-DC converters, which convert DC into higher (or lower) voltage DC
- Linear regulators, which regulates DC into lower voltage DC without conversion
- batteries, portable but limited amount of energy
Commonly used definitions:
- load: a circuit which draws electrical power from a power supply (a computer, a light bulb, etc.)
- mains: (generally) AC power provided by an electrical utility
- rectification: conversion of AC to DC
- converter: a circuit which changes voltage from one form to another (AC to DC) or converts DC to DC using a switching stage (DC -> AC -> DC)
- PFC: power factor correction, which generally refers to a circuit that converts the mains AC into DC while keeping the input current sinusoidal and in-phase with the voltage (making the power supply load appear resistive to the mains)
If your power supply can the same voltage and the same or more current, you are ok. The reference question for choosing a power supply is Choosing power supply, how to get the voltage and current ratings?
Common Switching-mode Power Supply(SMPS) Types:
- Buck: A SMPS that will take in a higher voltage and step it down to a lower voltage. An inductor on the output rail of the power supply is characteristic of this topology.
- Boost: A SMPS that will take in a lower voltage and step it up to a higher voltage. Generally an Inductor in the input rail to the power supply is indicative of this topology.
- Buck-Boost: A hybrid SMPS that is capable of both the buck and the boost topology. Generally this will have an inductor on both the input rail and the output rail of the power supply in which only one of them is internally engaged at one point.