Power Adapter: Everything You Need to Know(Full Guide 2022)

Last updated: September 21, 2022 at 11:50 am

Our devices are part of our daily essentials, and we rely on them in all aspects of our life. But to keep them running, we need to charge them regularly. It is where power adapters come in – they act as a go-between from the outlet to your device, translating the current so that it doesn’t fry your electronics.

While most of us don’t think twice about the power adapters we use, there’s much to know about these devices. This article will give you everything you need to know about this crucial little gadget.

What is a power adapter?

A power adapter is a device that takes power from an AC outlet and converts it into DC power. Generally, the power adapter contains a rectifier that changes the AC into the DC. The transformer then changes the voltage to become compatible with the device you are trying to charge.

This process is necessary because most electronic devices run on DC power, while AC power is what we get from our outlets. A wide variety of power adapters are available, but they all serve the same purpose – to power our devices.

The adapter will have plugs that fit into your device’s port. Several power adapters are available depending on the gadget in use. For example, there are power adapters for laptops, cell phones, digital cameras and other electronics.

Power Supply AC Plug

An AC plug is the attachment on the end of a power cord that goes into an AC outlet. Generally, there are three AC plugs – the two-pronged, the three-pronged, and the polarized plug.

The two-pronged plug is the most basic and oldest type of plug. It has two metal prongs – one is hot, and the other is neutral. The hot prong carries the current into the device, while the neutral prong returns the current to the outlet.

The three-pronged plug is similar to the two-pronged pin but has an additional ground prong. When a short circuit occurs, the ground prong creates a path for electricity to follow, reducing the shock risk.

The polarized plug is the most common type of plug today. It has two prongs – one hot and one neutral – of different sizes. The larger prong is always hot, while the smaller prong is always neutral. It helps to ensure that the current flows in the correct direction and prevents the risk of shock.

Power Supply AC Plugs differ depending on the country. US plugs have two flat prongs that are parallel to each other. EU plugs have two round prongs placed side-by-side, and UK plugs have three rectangular prongs arranged in a triangle. Au plugs have two flat prongs placed at an angle, while Koren plugs have two round prongs placed side-by-side. Brazil plug types vary depending on the region.

Knowing the power adapter’s plug type is essential when traveling since you must use a power adapter compatible with the outlets in the country you are visiting.

AC Pole for desktop power adapters

The term “power adapter” is also used to refer to the power supply that comes with an AC cable. This power adapter plugs into an AC outlet and provides power to the computer. Desktop power adapters typically have an output of 120 Watts, but there are also 200-Watt and 300-Watt adapters available.

The most common output is the 3-pin plug, which connects devices to the power supply. The 3-pin plug has three wires – the ground, live and neutral. Some desktop power adapters also have a 4-pin plug, which connects to devices that require more power, such as a graphics card. The 4-pin plug has four wires – the ground, live, neutral, and 12 V power supply.

The following are some examples of desktop power adapters and the desktop models they are compatible with:

  • C8 2 pins: Apple TV, Mac mini, and some MacBook models
  • C9 3 pins: Used by iMac G5 and early Intel-based iMacs
  • C14 3 flat pins: Used by MacBook Pro with Retina display 5.5mm x 2.1mm
  • C6 3 round pins: Used by MacBook AirHow to use a power adapter

DC connector

Laptop power adapters usually have a DC connector, which connects the adapter to the laptop. The DC connector has two parts – the inner part links to the notebook, and the outer part plugs into the AC outlet.

The inner part of the DC connector is typically barrel-shaped and has positive and negative signs. The outer part of the connector is usually cylindrical and has a pin that goes into the ground socket.

The most common DC connectors are 3.5mm, 4.0mm, and 5.5mm. Each size has a different diameter and is not compatible with connectors of other measures. The 3.5mm connector is typically used for small devices such as digital cameras, Audio devices. In contrast, the 4.0mm and 5.5mm connectors are used for laptops, and Universal Serial Bus (USB).

Some power adapters also have a USB port that can be used to charge devices that use a USB cable, such as a smartphone. USB ports are usually located on the side or back of the power adapter. The output of a USB port is typically 5 Volts and 1 Amp. Some power adapters have a higher output of 2.1 Amps, which is ideal for charging tablets.

Other power adapters have a DC port, which is located at the back of the power adapter and is used to supply power directly to the motherboard of a desktop computer. There are also Open End and unique ports like crocodile clips and Molex connectors, which aren’t very common.

Cable Length

The power adapter’s cable length also differs depending on the device used. For example, the power adapter for a laptop typically has a longer cable than the power adapter for a smartphone. They usually are 1.2m long; however, 1.5m to 3m are also available.

On the other hand, DC cables for desktop power supplies are usually much shorter since they only need to reach from the back of the computer to the power outlet. DC cables are typically 1m, 1.2m, 1.5m, and 1.8m in standard length.

Power Adapter Certificates

Power adapters must have specific certificates and safety approvals before selling them. The most common certificate is the CE mark, which indicates that the power adapter meets the safety requirements of the European Union (EU). Another standard certificate is the GS and TUV for Germany; cUL, FCC, ETL and Energy Star for North American countries; KC for Korea, PSE for Japan and RCM for Australia.

When purchasing a power adapter, ensure it has the appropriate certificate for your country. Otherwise, the power adapter might not work correctly or could be unsafe.

The connection between the Power Adapter and the device

A power supply connector connects the power adapter to the gadgets. It transforms the DC power to the device. Here are some typical power supply connection methods: Plug-in Connection, Terminal connection with screws, and Cable connection.

Plug-in Connection is for the power adapters with DC plug, USB port, and customized connectors. The terminal connection is for the devices that need some terminals for connection, like LED strips, CCTV systems, etc. We usually connect the devices with cable for LED products or the devices without ports.

How to choose the correct Power Adapter

Initially, you will have to identify what type of device you have and what connection it uses. Then determine the voltage and amperage the device requires, which are on the device or in the user manual. Once you know what type of connection and voltage/amperage the device requires, you can purchase a power adapter with those specifications.

Finally, ensure that your power adapter has the correct certificate for your country. Each power adapter will have different certification symbols depending on the country’s requirements.


Power adapters are handy but easy to ignore until they are needed. They provide power to electronic devices like laptops, smartphones, and tablets, which come in handy when traveling.

Power adapters can also supply power directly to the motherboard of a desktop computer. It can also charge batteries, which is especially useful for devices that do not have an AC adapter, like Bluetooth headphones or smartwatches.

When purchasing a power adapter, ensure that you get one with the correct voltage and amperage for your device and the proper certification symbols depending on your country. Knowing these things about power adapters can save you a lot of time and hassle in the future. Therefore, it is always best to get knowledge on these items you purchase so you can use them to their fullest potential! If need more help, feel free to contact us.

Are you trying to get the right power supply vendor? Let a reliable supplier provide you with high quality power supply solutions.

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