How Does A Power Supply Work?

Power supply forms the backbone of every electronic component that we use on a daily basis. Essentially, it converts AC (alternating current) power to DC (direct current) power. There are two types of power supplies that basically supply electrical appliances with DC power; the unregulated and regulated power supply. The unregulated power supply produces a set voltage at a maximum output current. The output voltage increases with an increase in output current while the regulated power supply incorporates all components of an unregulated power supply with the addition of a voltage regulator. Several steps are involved in the conversion of AC to DC power. In this article, I aim at looking at how supplies like the 12v power supply work in order to give the required output power.

12v power supply

How a power supply works

The 12v power supply is one of the commonly used power supplies in the modern world. But how does it work? Below are the steps involved in power conversion:

  1. Transformation

This forms the first step of power conversion. It involves the use of a transformer to step down the input voltage to a favorable voltage that the power supply can handle. A transformer consists of a primary winding and a secondary winding which are physically separated from each other. The ratio of the turns of the winding determines how much output voltage can be obtained from a transformer.

  1. Rectification

Once the transformer steps down the AC voltage from the main supply, the output voltage is passed through a set of diodes in order to obtain a raw DC voltage. This is known as rectification. The main types of rectification are;

  • Half-wave rectification: it uses a single rectification diode to convert AC voltage to DC waveform and is the easiest to design.
  • Full-wave rectification: it uses two rectifier diodes in the rectification process and gives double the voltage of a half-wave rectifier.
  • Bridge rectification: it uses four diodes that are arranged in a bridge formation. It gives same an output voltage as a full-wave rectifier. However, the diodes require half the reverse breakdown voltage of diodes used in full-wave rectification.

12v power supply

  1. Filtering

Filtering smoothen the DC voltage obtained from rectification. It works by removing AC ripples from the DC voltage. It is important because ripples can damage the load of the power supply which eventually can destroy the whole circuit. Filtering involves the use of a reservoir capacitor and a low pass filter which removes almost 95% of AC ripples when used together in the filtering process.

  1. Regulation

It is the final step which involves the use of a regulator to smooth out the dc voltage obtained from the filtering process. It also ensures that a constant output voltage is supplied to the load irrespective of variations of the input voltage.


12v power supply


Different power supplies including the 12v power supply are widely used in many sectors like manufacturing, telecommunications, military, and medical applications. They form the foundation of the successful functioning of various machines and appliances by converting AC voltage to DC voltage through various steps as outlined above.

Leave a Reply

Your email address will not be published. Required fields are marked *