Is There a Difference Between Power Adaptors and Plug Adaptors?

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Is There a Difference Between Power Adaptors and Plug Adaptors?

An adaptor is a device used to convert the characteristic elements of a particular electrical component to make it compatible in regards to a plug or power supply. Power adaptors and plug adaptors are two different devices that are often used in conjunction. A plug adaptor usually enables a device that is used in one region to be connected to a socket in another region. The fact is that some regions utilize different socket types from others, which requires travellers to utilize an adaptor in order to plug in their electrical equipment. The differences are usually noted in the contact points of the plug, which may have different shapes and a different number of contact points. The adapter does not normally change the voltage of the plug, unless it has a built in transformer.

A power adaptor is a transformer that is generally attached to the plug cable of many household items. It is used to adapt the electric household current from a high voltage to a lower voltage that is more appropriate for the electrical appliances that consumers use. Sometimes the adaptors may get relatively warm when it is actively converting the AC current to DC current, but it does not produce any environmental danger and can endure consistent prolonged use. Buyers need to fully understand the attributes and components of each adaptor type before deciding if they need to buy one or both of them for home use and travel.

Power Adaptors

A power adaptor has many names including AC adaptor, AC/DC convertor, plug-in adaptor, and line power adaptor. Despite the name used by certain retailers and consumers, the device still serves the same general purpose of converting power. The power adaptor can be considered an external power supply that collects the high voltage from the household socket and converts it to a lower DC voltage that the electrical device can use. The adaptor is generally seen attached to electrical devices that needs power but do comprise the necessary internal mechanisms to develop the needed power voltage from the household socket.

However, the circuitry structure of these external power supplies is still comparable to the designs of a built-in one. External power supply adaptors are used with two types of equipment: ones that have no additional source of power, and ones that also have a battery power supply that can be charged when the external power supply is plugged in. Laptops and cell phones are good examples of electrical devices, which use both external and battery power supplies.

Linear Power Adaptors vs. Switching Power Adaptors

In the beginning, most power adaptors were linear power supplies, which comprise a transformer that converts the electricity voltage from the main to a lower voltage, and a rectifier, which converts the electricity to a pulsating DC. Additionally, those early power adaptors would also have a filter to level out the pulsating waveform, which creates residual ripple variations but not enough to affect the device.

Linear Adaptors

The transformer within the adaptor is determined by the mains frequency and power output. This in turn affects the overall weight and size of the adaptor. If the ratings were more than just a few watts, the linear adaptors would have to be large, which would render them too heavy and cumbersome to be adapted to a regular wall socket. The actual output voltage of linear adaptors would vary by the load, where electrical devices that needed more stable voltage would add linear voltage regulator circuitry. The problem with these adaptors included considerable losses in transformers and linear regulators, low efficiency, and dissolute power, even when there was no load to drive.

Switching Adaptors

However, in the early part of the 21st century, switched-mode power adaptors were universally revolutionized. These switched-mode power supplies (SMPSs) rectify the main voltage to a high direct voltage that drives a switching circuit. The adaptor comprises a transformer that operates at a high frequency, which outputs the DC at the needed voltage. This high frequency can be filtered out more easily than the mains frequency, and it also allows the use of a small transformer, which reduces loss. Additionally, it increases the efficiency of the switching regulator, which results in a much smaller, lighter and efficient power adaptor. Even though a higher frequency is used, the device is still safe because the transformer still isolates the output from the mains.

Linear Circuitry vs. Switching Circuitry

Linear circuits generally have a design for a specific range of input voltages, which are generally narrow, such as 220 and 240V AC. They must also utilize a transformer that is conducive for the frequency, which is generally 50 or 60 Hz; however, SMPSs can be designed to operate efficiently on a wide frequency and voltage range.

On the other hand, switching adaptors may fail more frequently than linear adaptors if they are not designed carefully with appropriate components. This is partly due to their complex circuitry and the fact that they use semiconductors. In essence, if they are not properly designed and built, they may very well become damaged from overloads, even those that occur due to lightning, short overvoltage, and component degradation, among other things. Switching regulators often fail because they use electrolytic capacitors, which comprise an equivalent series resistance (ESR) that increases with age. Therefore, these regulators have a profound sensitivity to ESR and have a more dramatic effect of degradation than the linear ones.

Good power adaptors have circuitry that pays close attention to the level of ESR, pulse operation, ripple current rating, and the capacitors’ temperature rating.

Plug Adaptors

Plug adapters are sometimes called AC power plugs, and they go hand in hand with wall sockets. Plugs and sockets enable electronic devices to be connected to the AC power supply in the home or any electrically wired building. Different electrical plugs and sockets in different regions have varying current and voltage ratings, connector types, sizes, and shapes. Each country in various regions has a national standard that governs the building sockets and the plugs on the electrical devices.

The plug is the end connector of a power cable for an electrical device. This section is then plugged into the socket, which is the stationary fixture in the building’s structure that provides the main power. Plugs are considered male circuit contacts, and sockets are the females. This is due to the fact that the plug is designed with pins, prongs, or blades that protrude from the base and fits into the holes of the corresponding socket.

Plug adaptors are simply used to adapt one plug type to the attributes of another plug type so that it fits correctly into the desired socket. For instance, the europlug standard comprises of two round pins, while the British standard 546 plugs have three large round pins situated in a triangular manner; therefore, an adaptor would have to be added to the europlug of a device so that it can be plugged into a British standard socket.

Plug Adaptor Variation Chart

Plug adaptors are generally used by frequent travellers or when an electrical device is bought from another region. This is often the case with cell phone chargers and plugs for electrical razors. Additionally, there are two main types of voltage and frequency throughout the regions: 120 V at 60 Hz governs the North American region, and 220 - 240 V at 60 Hz governs the European region.

Country /Region

Plug Type

Plug Description


10 A (or 20 A), 250V defined by IRAM; used in Class 1 applications

Three-wire earthed plug; similar to Australasian and Chinese plugs

Australia, Fiji, New Zealand, Tonga, Argentina, Solomon Islands, Papua, New Guinea, China

Australasian 10 A/240 V

A grounding pin plus two flat current-carrying pins in an upside down V-shape


BS 546

Three large round pins in a triangular pattern


BS 1363

Three rectangular pins that forms a triangle


BS 4573

Two round pins across from each other


16 A/250 V grounded

Two symmetrical round receptacles plus two grounding clips on the sides


CEE 7/5

Two round pins


CEE 7/7

Grounding clips on both sides to connect


CEE 7/16

Two round plug


CEE 7/17

Two round pins



Round power pins and half round ground pin


CEI 23-16/VII

Three round pins


GOST 7396 C 1

Two round pins


SEV 1011

Three round pins


IEC 60906-1

Three round pins



Plug is three wires



Three flat pins in a rectangular form

North America

NEMA 1-15

Two flat parallel non-coplanar blades and slots


NEMA 5-15

Two flat parallel blades like NEMA 1-15, but also adds a grounding blade


JIS C 8303, Class II

Plug appear physically identical to NEMA 1-15


JIS C 8303, Class I

Plug appear physically identical to NEMA 1-15


TIS 166-2549

Three round pins

Most plugs can be used across multiple regions, but it is always best to buy power plugs that specify a particular country in its sales listing. However, buyers can use the chart above to learn the physical characteristics of various plug types in order to better identify them by sight.

How to Buy Power Adaptors and Plug Adaptors on eBay

You can easily find power adaptors and plug adaptors on eBay, but it is best to search for them individually. Start by performing a search for power adaptors on the eBay home page and wait for the results to come up. They may also include some plug adaptors, but unless you are in the market for one of those too, you can bypass them and search for a power adapter that fits with your device.

Alternately, you can forgo the general search and type in specific criteria for the particular device that you need the adaptor for. For Instance, if you own an Acer laptop and its power supply is missing or is damaged, you can search for "Acer laptop power adaptor" from the home page to narrow your search results.

The same manoeuvre can be applied to buying a plug adaptor, but the specifics are not so much about a device, but rather the design or region that it is used in. For instance, you could search for a "UK plug adaptor" or a "3 pin plug adaptor" to narrow the results. Once all the necessary searches have been conducted and criteria filled in, you can now select one or two items, and then contact the sellers for additional details if necessary.


The major difference between a power and plug adaptor is their purpose. One is to regulate power, while the other is to regulate a connection. Once buyers become aware of the differences, they can able to purchase the right item that they need. Buyers need to understand how a power adapter works and the two major types that exist. They also need to know that many devices use a power adapter even when they have an internal power source or a battery.

Plug adaptors are even more popular and easier to understand. The basic concept is to know the various connection elements and the associated sockets. In essence, buyers should always consult a plug adapter guide or chart to know which adaptor type is suitable for any area that they may need to travel. Due to the fact that there are many types of adaptors available, buyers should equip themselves with the necessary knowledge to find the right one.

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