How Does AC-DC Power Supply Work?


A power supply is referred to as an electrical device, which works to supply electric power to an electric load. The core function of a power supply is to change electric currents to the right voltage or frequency.

When we talk about the power supply, there are two names that stand at the forefront; AC power supply and DC power supply. And in this section, we will be learning all about them.

What is the AC Power Supply?

Alternating current or AC power supply is the conventional electricity format that is produced from the outlets. In the AC power supply, the current is transmitted in the form of waves. Its wave-like current is why the power supply is named as alternating current. The electrical current within the waves is obtained by the electron. AC can be generated through an alternator. It encompasses a wire, which is looped up in a magnetic field. When there is consistent rotation, the wire moves to different magnetic polarities, generating waves.

What is DC Power Supply?

Direct current or DC power supply makes use of electrons that moves in a linear path. The direct name current is given due to the direct movement of the current. In this, the current is generated from batteries, solar cells, commutators, alternators, rectifiers, etc. DC offers consistent voltage, which is why it is considered ideal for many electronic devices. In fact, many devices convert AC power into DC in order to get consistent power supply and higher security.

AC-DC Power Supply

In many buildings, devices are powered by AC-DC power supplies. AC-D power supply basically converts the AC power generated from the wall outlets and transforms it to unregulated DC power. These supplies include transformers that convert the voltage of AC from wall outlets, filters that reduce the unwanted high-frequency noise, and rectifier to convert AC to DC. Essentially, it works to reduce the voltage by the transfer to the required voltage by a different device.

To begin with, by leveraging different diodes, the voltage is rectified. In this process, the sinusoidal AC wave is converted into a collection of positive peaks via a rectifier. However, there is still certain wave fluctuation that needs to be removed.

In order to achieve that, a capacitor is used by designing an effective energy reservoir that is integrated into the load while the voltage is being dropped.

Additionally, it amalgamates the incoming energy in the increasing portion and expands the same when the voltage drops. This process considerably reduces the chances of wilt in voltage. It is considered that the higher capacity of capacitors, the greater will be the power supply quality.

Once the voltage is a converter, the output variation is flattened by moving the voltage through a regulator in order to generate a stable DC output.

There are two types of AC power, including regulated and unregulated. In the case of an unregulated supply, the voltage ripple remains within the output voltage. Since unregulated supplies display ripple voltage, the regular supply is always used over the former in case of ambiguity with regards to the application. An AC-DC power supply generally contains a regulator because ripple voltage can damage the delicate electronic component.

DC-DC Power Supply

Devices that are powered by solar cells or batteries need DC power at different voltage levels. This calls for the need for a DC-DC converter. This form of power supply basically converts the current, which is directly coming from the source from a voltage level to another based on the need of the device at that particular time.

The way a DC-DC power supply functions depend on the device and the type of converter being used. In many cases, the process includes rectifiers and inverters that initially transfer the DC power into AC. Thereafter the power is transmitted to a transformer to alter the voltage. Once it has achieved the right voltage level, the current moves back to the rectifier, wherein it is again transformed into DC power.

Final Thoughts

AC power supply and DC power supply, both carry their own significance. And in a majority of cases, they are dependent on each other. AC-DC power supply shows how both the factors work together to generate adequate power supply to ensure different devices function adequately and efficiently.

Ac-Dc power supply