Sometimes small electronic components can make a big difference, such as audio, USB and DC connectors. Two jacks or plugs may look the same, but require a specific size and rating to match. DC power connector selection is an often overlooked aspect of an engineer’s final design. Although the DC power connector is a relatively straightforward component, a basic understanding is required to ensure the correct connector selection.
What is a DC Power Connector
DC power connectors, also known as barrel connectors, have manufacturer-specified current and voltage ratings to ensure reliability in power delivery applications. The three main types of DC power connectors in the electronics industry are jacks, plugs, and receptacles. A DC power jack is installed on a PC board or chassis and receives power. The DC outlet also receives power, but is connected to the end of the power cord.
At the same time, when a DC power plug is connected to a jack or socket, it provides power from the mains.
The jacks and plugs of standard DC power connectors typically have two conductors. One conductor is exposed and the second is recessed, which helps prevent accidental shorts between the two conductors. Since barrel connectors are almost always used to power the end application, there is little risk of damaging other components by plugging the DC power connector into the wrong port.
Gender Definition of DC Power Connectors
Gender definitions for DC power connectors are less standardized than definitions for jacks, plugs, and receptacles. Connectors with center pins are accepted as male and mating connectors are accepted as female.
The DC power connector consists of three pins. Pin 1 represents the common pole, which is the negative pole, and pins 2 and 3 are the same pole, which is the positive pole. Pin 2 is for internal power, and 3 is for external power. In normal use, pins 2 and 3 are on, and the internal power supply is used. When an external power supply is plugged in, pins 3 and 2 are disconnected. At this time, pins 3 are directly connected, and the external power supply supplies power through pins 1 and 3. 2 pins are disconnected at this time.


Applications of DC Power Connectors
Audio connector for power supply
A DC socket is a socket matched with a special power supply such as a computer monitor to provide DC power to the equipment used. Application as below:
- Audio and video products: MP3, MP4, DVD. Audio;
- Digital products: digital cameras, digital video cameras, etc.;
- Remote controls: remote controls for vehicles, rolling doors, and home anti-theft products;
- Communication products: mobile phones, car phones, telephones, building equipment, PDAs, etc.;
- Household appliances: TVs, microwave ovens, rice cookers, electric fans, electronic body scales, electronic fat scales, electronic kitchen scales, etc.;
- Security products: video walkie-talkies, monitors, etc.;
- Toys: electronic toys, etc.;
- Computer products: cameras, voice recorders, etc.;
- Fitness equipment: running machines, massage chairs, etc.;
- Medical equipment: sphygmomanometer, thermometer, hospital call system, etc.
USB connector for power supply
The power adapter DC plug, also referred to as the DC head, is a connector for the power adapter to connect to the product it supplies. It is composed of a tuning fork-type metal contact shrapnel or a metal hollow cylindrical contact body, an insulating base, a transverse socket, a longitudinal socket, and a directional keyway adopted by the tuning fork DC head. The inner diameter and outer diameter of the DC plug of the power adapter are as follows: 5.5*2.5, 5.5*2.1, 4.75*1.7, 4.0*1.7, 3.5*1.35, 3.5*1.1, 3.2*0.9, 3.0*1.1, 2.5*0.7, 2.35*0.7, 2.0*0.6 in MM and so on.
installation of DC power connectors
The first is to connect the inner core to the power input. Then the remaining two ends are connected to the positive and negative poles, because the general circuit is determined by the circuit of the device, and the main circuit is mainly composed of NPN polar components. This circuit uses the negative pole of the power supply as the common ground. Therefore, the DC interface of these devices uses the negative pole as the ground terminal, so the outer shell of the power plug should be connected to the negative pole of the power supply, and the inner core should be connected to the positive pole.


Choose the DC power connector you need
Choosing the right DC power connector by you need with the right information, DC power connector selection shouldn’t be a problem. Pay attention to the diameter and insertion depth of the inner pin and outer sleeve to ensure a proper mating connection between the jack and the plug. BITUO offers a range of DC power jacks, plugs and receptacles with a variety of mounting styles and other configurations, while pairing guides on each product page further simplify the process of finding compatible jacks and plugs.