In electronics and electricity, connectors are a very important part of every system, since it provides a series of advantages over having cables attached directly to boards or devices, from a faster replacement time to a higher compatibility with similar devices. An electrical connector, by it-self, is an electromechanical device used to join cables and conductors so electrical circuits can be completed.
Nowadays connectors technology is continually evolving, to the point that one of the biggest achievement that many engineers are trying to get, is to make an universal connector, right now USB Type-C is the best example of this since, in some cases, you can even recharge the battery of a phone with the same cable used to charge the battery of some laptops.
Depending on the field or utility, a connector can have a series of specifications, compatibility agreements and unique characteristics for particular situations, though, in many cases, adapters can be used to join different connectors. According to their function, connectors can be classified in four different groups, inline or cable connectors, chassis or panel connectors, PCB mount connectors and Splice or butt connectors.
The first thing to have in mind when looking at the specifications of a connector, is that there are two formats of connectors, a male connector, also called plug, and a female connector, also called socket. Most of the time, the male connector is attached to the cable and the female connector to the chassis of the device or power grid, being the male connector the one showing pins, with the exception of power supply cables, which must have a female connector since there would be a significant risk on leaving the pins with electrical charge exposed.
The number of pins is another important thing to note, since their number can change depending on the necessities of the system, it is a common practice to choose a connector with more pins than needed, in case of new requirements that could be found in the future.
Maybe the most important specification is the amount and quality of the current that the connector can sustain, which come in hand to other factors like size, and covering and construction material. Of course, normally it is just necessary to pick connectors that can sustain a level of power higher than the actually needed in the system, but many times, it is necessary to pick a connector that can guarantee, as well, a good quality of the signal, this is normally since in low current operations.
Following the same line of thought, voltage is an important variable at the moment of choosing a connector, although in most daily applications any connector will be able to fulfill its mission, is when voltage gets to hazardous levels when it must be looked at.
For instance, sometimes might be necessary a connector that is well protected from wear and external circumstances, since it could mess with the actual resistance of the connection, and make necessary certain levels of current to actually achieve conductivity. A good example of this are the gold-plated contacts used in some data and sound devices to improve quality. In more specific circumstances, there could be some electrical requirement, for instance, the necessity of coaxial connections for some data connections.
Other important considerations might be taken around external and mechanical specifications like physical size and shape of the connector, moreover, the necessity of some environmental requirements like temperature range, moisture resistance or even pressure. Insertion force is a specification that for most applications it won’t be a problem, but for some specialized fields it must be taken in account.
The last, but not less important consideration, is the number of insertions, this describes the amount of insertions it takes to start expecting failure of the connector, it is very obvious to expect the cable to wear little by little every time it is continuously connected and disconnected. It has to be in mind that not every time a huge number of insertions is required, for instance, if a device is just meant to disconnect for maintenance or repair times, the number of insertions might not be an important factor as it is for common general use devices.
Most people don’t know how important is the process of choosing the right connector for a specific application, it requires to think in everything that the device needs and the conditions in which it is going to be put through, to make sure everything works as intended by the manufacturer and give a good experience to the consumer.