How do I select the right DC plug for the Wall plug adapter

Table of Contents

A Wall plug adapter has input and output voltages, so it usually has associated input and output connectors. The various connectors available for input and output power transmission cannot be reasonably covered in a single document. This discussion will focus on the DC power connector (output) for the wall plug of the power adapter. You can log on to to download to see JPTPower about DC plug-in list details.

Wall plug adapter Connectors:

There are many types of DC PLUG connectors, and many more non-standard connector versions. The standard connectors we will discuss include cylindrical connectors, DIN connectors, and USB connectors.

Some of the features associated with these three types of DC output power connectors are listed below:

Barrel Connectors

Power DIN Connectors

USB Connectors





Higher current

Finite current

No customization

Strong and durable

Transmit information

Barrel Connectors:

Cylindrical shapes, usually made of metal or plastic, with inner frames and enclosures designed to interlock to provide a reliable interface.

The most dominant feature is that the outside diameter, inside diameter and length of Barrel Connectors can vary so that different power requirements and voltage levels can be supported. It is widely used in the output interface of the Wall plug adapter, in other consumer electronics, monitoring equipment, power tools, household appliances and other products are widely used.


The most commonly used DC Wall plug adapter includes 5.5*2.1mm, 5.5*2.5mm, 3.75*1.35mm. The PLUG is paired with the DC JACK, which is usually integrated in electronic devices. It has a central PIN that can be perfectly inserted into the Barrel Connectors, but it should be noted that the DC PLUG comes in many sizes, and it is important to pay attention to whether the size is correct before use.

Barrel Connectors polarity symbol:

The sexual pole of Barrel Connectors depends on what polarity your electronic equipment needs. In general, people habitually use the Centered positive. In this case, you need to check the logo on the nameplate of the wall plug adapter to confirm the output polarity of the power adapter. This is important because it is easy to damage your device if it is reversed.

Power DIN Connectors:

The DIN Connectors (DIN Connectors) are round, multi-pin connectors originally developed by the Deutsches Institut fur Normung (Commission for Standards in the Electrical Industry). DIN connectors typically have a 13.2mm diameter circular housing with a varying number of circular interfaces inside to transmit different types of signals, including audio, video, power, etc.

DIN connectors are characterized as follows: Usually there are 2, 3, 4, 5, 6, 7, or 8 round jacks. The case and plug can be made of metal or plastic, it can withstand higher currents, easy to use and reliable, because the plug can be automatically locked from the socket to the plug. DIN connectors can be used in audio interfaces (such as MIDI interfaces), video interfaces (such as SCART interfaces), and automotive electronics, instrumentation, industrial control, and medical devices. Overall, the DIN connector is a common connector used in a wide variety of devices and industries.

USB Connectors:

USB connectors were originally designed to transmit direct current and digital signals. Because USB power voltage levels and connectors are widely accepted, they are also used in pure power applications, and the most popular USB connector by far is the Type A connector, available in applications that require 5V DC voltage and load current levels less than 2A. Variants of USB Type A connectors (e.g. mini, micro, etc.) are also used for similar power transfer applications. One limitation of the USB Type A connector and its variants is that only one connector is oriented correctly.

This restriction requires the user to determine the correct orientation of the plug and socket through visual identification or attempted insertion. The USB Type-C connector is more compact and can be inserted in all directions. The Type-C connector can deliver higher power levels than previous versions of the USB connector and is rated to provide up to 20V, 5A power.


As there are many types of output connectors, consumers need to pay special attention to whether the output interface matches their electronic products when buying the wall plug adapter. There are more decisions to be made for designers. Because the output DC power plug should have different output voltage and current ratings, and must also consider the desired mechanical characteristics of the product. JPTpower has sales technicians who can help you with all your connector problems with power adapters.


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