AC/DC power supplies
Introduction
Definition of AC/DC electrical supplies
AC/DC power supplies are devices or systems that convert alternating current (AC) from the electrical grid into direct current (DC) that is used by various electronic and electrical equipment. These power supplies are essential in industry, electronics, and residential applications, since many devices require direct voltage and current for their correct operation.
The term AC/DC refers to the ability to transform and adapt electrical energy from one type to another, ensuring that connected devices receive adequate, stable and safe energy. These power supplies can be simple or complex, from a simple power adapter to industrial systems with advanced regulations.
Principles and operation of AC/DC supplies
Conversion from alternating current to direct current
The fundamental principle of an AC/DC power supply is the conversion of alternating current, which periodically varies in magnitude and direction, into direct current, which maintains a constant unidirectional flow. This conversion is done to power electronic devices that cannot operate on alternating current due to their sensitivity or design.
The process begins with the input of alternating current from the electrical grid, which usually has a frequency of 50 or 60 Hz and a standard voltage depending on the region. This current then goes through transformation and rectification stages to obtain a continuous signal. Rectification is commonly performed by diodes that allow current to pass in only one direction, eliminating the negative component of the alternating signal.
Subsequently, the rectified signal is filtered using capacitors or inductors to smooth out the ripples and achieve a more stable direct voltage. In more advanced supplies, regulators are incorporated to keep the output voltage constant, regardless of variations in the load or input voltage.