Electrical connector — Everything You Need to Know

We usually never give the electrical connector a second thought. They sit at the end of the product, and we mostly ignore their importance.

Electronic equipment will not work without electrical connectors! You have to count in several factors while choosing a connector- what will be the cost factor? Where will be the connectors used? What should be the spacing and pin count?

Surely, there’s a lot of things to process. To help you out, we are going to take an in-depth look at electrical connectors in this article. By the end of the guide, you will know all you need to make an informed decision and choose the best product. 

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Chapter 1: Electrical connectorWhat is a Connector

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Electrical connectors allow you to join various components of an electrical circuit like wires and cables. The connectors create a continuous path for the electrical current to flow through the connection or circuit.

Connectors can come with male-end plugs or female-end jacks. You can join them together to form a temporary or permanent connection based on your needs.

Electrical connectors facilitate manufacture, assembly and installation of electrical devices by cutting down labor, time and effort. Electrical connectors are widely used in electronic devices, domestic appliances, telecommunication, industrial machinery, computers, and automobiles.

Here’s a video of how connector blocks work-

Electrical connector–Basic Composition

Electrical connectors consist of mainly two parts- the housing and terminal.


The housing is the case which contains the terminals. Housing stabilizes the connection and keeps the electrical contacts safe from environmental hazards and short-circuits.

Generally, manufacturers use molded plastic for the housing, but you can also use other insulating materials like ceramics.


Terminals refer to the pins on the connector that establish the electrical connection. The Terminals are mostly made of metals, but you can also use other conductive materials like silicon or carbon.

Features of Connectors

You will need connectors with different features for some specific applications. Here are a few important features-

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Keyed Connector:

Keyed connectors can only be connected when they are in the proper orientation. The design helps you connect in the right direction preventing damage to the pins.

Lock Connector:

Locked connectors come with a locking mechanism to hold the connectors in place. They prevent the connectors from dislodging or breaking away accidentally during movements or vibrations.

Sealed Connector:

Sealed connectors are used for applications that need to withstand water and water pressure. They can be used underwater up to certain depths.

Waterproof Connector:

As the name implies, the connectors are resistant to water splashed or dampness. But you can’t use them under water.

Moisture-Proof/Oil-Proof Connector:

The connectors are designed to protect the connections from oil or moisture damage.

Filter Connector:

Filter connectors protect the electrical connection from interfering electrical signals like electromagnetic interference (EMI) or radio frequency interference (RFI).

Shield Connector:

Shielded connectors protect the wiring and components from electrostatic discharge.

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Now we will take a look at the different types of connectors. 

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Chapter 2: Electrical connector–Types of Connectors

Electrical connectors come in all sizes and shapes. You can divide individual connectors into various types based on levels, application, and nature of terminals.

Connector Level

Electrical connectors can be classified into one or more categories, known as levels in the professional realm. The levels were put forward by various companies with the guidance of the National Electrical Distributors Association (NEDA). The levels include-

  • Wire-to-board or subassembly-to-subassembly level
  • Box-to-box or input/output level
  • IC chip or chip-to-package level
  • IC package or package-to-board level
  • PC board-to-board level

Main Connector Types

Let’s discuss some of the main types of connectors based on use.

1. Electrical connector–Audio and Video Connectors

Audio connectors connect cables to audio equipment for carrying electronic signals. You can use them to connect telephones, microphones, and speakers. Video connectors establish connections carrying analog or digital video signals. You can use them at the end of cables, connect electronic devices and other devices with video input or output.

The connectors have a male or female plug with shielded cables.

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2. Electrical connector–Automotive Electrical Connectors

Connectors are an integral part of modern automobiles using microprocessors and extensive wiring. The connectors enable connections with different interfaces required for the proper functioning of the automobile. Many vehicle systems like sensors, power windows, doors, and ignition system, need electrical connectors.
Automotive connectors can be of different types like power connectors, audio connectors, B-group connectors, C-group connectors, and D-group connectors.

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3. Board Mount Connectors

Board mounted connectors are also known as circuit board connectors and used to connect components on a computer board. The connectors are embedded on the boards, and you can customize them to meet various applications.

Board mounted connectors take help of pins to establish a connection between boards. You can also use them to connect USB or audio wires to the board.

4. Board to Board Connectors

Board to Board connectors are ideal for connecting printed circuit boards or PCBs. Each terminal of the connector links with separate PCBs to create a continuous connection. 

The biggest advantage of the board to board connectors is that you don’t need to use wires. The connectors are generally made of plastic and have metal pins or connectors.

5. Circular Connectors

Circular connectors come with multi-pin connectors and applicable for external interfacing. The connectors are useful for transferring data, the transmission of electrical signals and relaying power to devices.

Circular connectors are also called power and control connector as they can carry mixed signals. In industrial applications, the housing is either made of plastic or metal and fulfill the needs of a reliable and secure connection.

6. Coaxial Connectors

Coaxial connectors or coax are used to transmit radio frequency (RF) signals for CATV applications. The connectors have an insulated conductive inner wire covered in a shielding conductor. On top of that, you can find another insulating or protective layer.

Coaxial connectors are designed to carry a huge amount of information. They are also common connectors used in most home video installations.

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7. DIN Connectors

DIN connectors follow the standards created by the DeutschesInstitutfürNormung (DIN), a German organization for establishing national standards. The DIN connectors are commonly used in various applications like network, microphone, audio, video, data, and telephone.

DIN connectors can be both male and female and can carry high-frequency signals through multiple pins. Computers also use DIN connectors to connect microprocessors and RAM.

8. DB Connectors

DB connectors are officially known as D-subminiature connectors and used in data, computer and audio/video applications. The name comes from the “D” shape of the connector which houses two rows of pins. You can find DB connectors like DB9 and DB25 in serial and parallel port connections in PCs.

DB connectors may also have thumbscrews to secure them in place.

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9. Edge Connectors

Edge connectors or edge card connectors form an external electrical connection by pairing with single-sided or double-sided PCBs. They are embedded on the board and follow industry standard power specifications like power requirements, pin locations, and voltage levels.

The housing is made of plastic while the contacts use metal and come plated with a metallic coating for improved conductivity.

10. IC Interconnect Components

IC Interconnect connectors create a connection between PCBs and microelectronic semiconductor chips. The device closes the gap between two conductors allowing the transmission of current or light waves between the conductors. The package comes with an integrated circuit (IC) on a metal die along with an enclosure made of metal or plastic.

IC Interconnect components are an important part of many present-day electronic systems.

11. Instrument and Computer Power Connectors

Instrument and computer power connectors connect the power supply from the SMPS to various devices such as hard disks, CD and DVD drives, cooling accessories such as fans and thermal coolers and more.

The connectors use a plastic housing with four wires that carry 5V and 12V power and two grounds. They often have different features based on the application.

12. Medical Electronic Connectors

Medical electronic connectors are used in various medical equipment and devices found in clinics, hospitals, and other healthcare facilities. They can be of various types based on application and include circular connectors, coaxial connectors, micro connectors, and heavy-duty rectangular connectors.

Medical connectors can be both male and female.

13. RF and Microwave Connectors

RF and microwave connectors connect the end of cables of devices that use radio frequency or microwave spectrum. The connectors are used to transfer electromagnetic energy and RF signals in case of wireless broadcasting or communication.

The connectors are also commonly found in transmission systems and can couple and uncouple system components.

14. Solar Connectors

Solar connectors are quite common in solar energy systems. The connectors can establish a connection between the solar modules and set up a complete electrical system for your property.

You will mostly see the MC4 (multiple contacts, 4 mm pin) connectors which match with most models of solar modules. The male and female ends can be easily connected using hands, though you will need a tool to detach them.

15. Solenoid Valve Connectors

Solenoid valve connectors are used to form a connection between pressure switches and solenoid valves. The valves also serve the purpose of environment-proof junction boxes and can work with AC or DC voltages. The security boxes can function with pressure switches or solenoid valves.

Solenoid valve connectors have various standard specifications and feature options.

16. Terminal Blocks

Terminal blocks small insulated blocks that connect two or more wires. You can use terminal connectors to fix or terminate wires, and they come with multiple individual terminals. Terminal blocks are often used to secure wiring to ground, or connecting switches to the mains.

You can purchase terminal blocks with a different number of terminals and wire sizes.


17. USB Connectors

The USB connectors can connect devices using the Universal Serial Bus (USB) standard ports. USB has high data transfer speeds of 12 Mbps in the 1.1 version. Different computer devices and peripherals use USB connectors to connect with the PC, and even smartphone chargers need them.

USB connectors are available in USB-A, USB-B, UBS-C, and mini/micro-categories. USB comes with hot plugging and plug-and-play feature.

18. Wire to Board Connectors

Wire to board connectors are connectors attached with wires which interconnect PCBs. The terminals are placed in individual housing to establish connectivity between circuits. The connectors feature a locking technology to secure them in place.

You can find a wide variety of wire to board connectors including FFC connectors, IDC connectors and RMC connectors. FFC connectors are ideal for connecting a bunch of wires to carry data from the board to board or from one part of a board to another

19. Wire to Wire Connectors

Two wire-terminated connectors can be connected using wire to wire connectors. They can serve as electrical connectors, electronic connectors or computer connectors. Male wire to wire connectors plugs into the female wire to connectors to form a connection.

Chapter 3: Material of Connector

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Electronic or electrical connectors are made up of insulating and conductor materials. The common materials used to make connectors include plastic and metal, though you can also use other materials. The conducting material is of importance as they impact the electrical contacts such as mechanical durability, conductivity, resilience, and formability.

Some common terminal materials you can use are-


Brass is the cheapest metal you can use in terms of weight. Generally, the zinc content in brass can range between 5% to 40% based on the application. Brass offers considerable strength, good spring and adequate electrical properties.

Brass connectors are mainly used for KK terminals.

Phosphor Bronze

Phosphor bronze is tough and offers increased strength compared to brass. It comes with impressive conductibility and superior fatigue resistance. Phosphor bronze also has excellent elasticity making it suitable for use in electrical contact springs.

Beryllium Copper

Beryllium copper is the best type of copper alloy for spring terminals. It contains around 0.5% to 3% beryllium with other elements. The alloy offers high strength and is cheaper than phosphor bronze.

High Copper Alloy

High copper alloys contain a high percentage of copper (more than 96%) and are suitable for demanding applications. The alloys have high strength coupled with excellent thermal and electrical properties. You can also use them in high-temperature settings as they don’t soften easily.

High copper alloys are mostly used in automotive applications.

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In the next chapter, we will cover the considerations when choosing electronic connectors.

Chapter 4: Factors to Consider When Purchasing Electrical Connector

You have to consider many factors to choose the right connector for your application. Many types of connectors are available in the market, so make sure you choose wisely. Here are a few factors worth considering-


Cost is usually an important consideration for many engineers and manufacturers. After all, you want to have the best at the lowest price possible, right?

Even that is your goal, don’t make the mistake of choosing your connectors based on the only cost. You may end up with cheap products which don’t do their job and lead to the failure of your project.

So always look for quality and try to strike a balance with cost to enjoy the maximum cost-effectiveness.

Electrical connector–Environment

The environment where you will use the connectors is also crucial. Will the connectors be used on bare ground or in the water? Or in a boat? Will the connectors encounter extreme weather? Will the project involve vibrations and shocks?

Select the best connectors based on your use environment. You should go for connectors with environmental sealing if you need protection against dust, vapor, liquids or combustible gases.

Determine the level of safety you require and then choose the connectors. Also, keep the operating temperature range in mind while making your selection.

Signal Type

You will need to choose the connectors based on the signal they transmit. Signals can be analog, digital, or a combination of both. If the signal is analog, then what is the frequency? Does it involve audio or RF? What is the bit rate or clock speed for analog signals?

The type of signal decides the type of connector, pinout, and wiring you will need.
Remember that you cannot use certain signal combinations in the same connector. You will need to consider clearance distances and creepage for high-voltage pins. You can also go for a custom solution based on your unique needs and design specifications.

Power Level

The level of current passing through your connector will also influence your choice. For high current paths, you will need multiple larger and thicker pins. If you are dealing with high voltage, then go for a connector with more insulation. For high voltage pins, you may also need to consider clearance distances and creepage.

Electrical connector–Ruggedness

The frequency of your terminals determines the strength of the connectors you need. Will the terminal be often plugged in and plugged out? Choose a connector with appropriate ruggedness based on your application.



The electrical connector is important for the smooth operation of any electronic equipment. It’s always wise to go for reliable and quality terminals which ensure the success of your project. Get in touch with us today to get more information on electrical connectors and custom solutions.

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