All About Wires, Cables, and Connectors
Even some of the most advanced electronic devices are rendered obsolete without the use of wires, cables, PCB controllers, or other assorted electrical hardware. Wires, cables, and connectors alike have important roles in electronics. In this blog, we will discuss each device and their differences.
Most wires are made from aluminum or copper. After the ore is refined, the metal is pulled into thick coils known as rod. Rod is processed in large spools and subsequently fed into a series of dies and rollers that stretch it out into its final thickness or ‘gauge.’ To be useful and for safety, bare wire is covered in a constant insulating sheath of various types of plastics that withstand extreme temperatures, solvents, water, and UV light. This is performed with a plastic extrusion process similar to that used to produce plastic bottles. Very few types of plastic are suited to insulation, as they must be durable, flexible, accepting of different colored dies, and relatively inexpensive. Common materials include polyethylene (PE), polyurethane (PU), rubber, and polyvinyl chloride (PVC). Higher grades of material for better durability and mechanical strength are also available, such as nylon, silicone, fluorinated ethylene propylene (FEP), and Polytetrafluoroethylene (PTFE).
While a single, solid metal strand is considered a wire, multiple strands or bundles of wire are called cables. In either case, they are conductors for electrical signals. Wires and cables come in many types and sizes for power transmission and telecommunication. Telecom cables are commonly shielded, utilizing an added outer mesh of conductor separated from the inner core by a layer of insulation. The outer mesh is intended to prevent accidental electromagnetic radiation in the environment, such as radio, TV, or cell phone signals, from interfering with the transmission.
Wires and cables alone cannot do anything. To function, they must be connected to something. This is where connectors come in. Connectors use a metal terminal that is crimped or soldered to a corresponding conductor, all placed within a plastic shell. Connectors serve to make mechanical joints between male and female terminals, holding the unit in place while simultaneously protecting it from the outside environment. Connectors can typically be separated for maintenance or replacement, making them a crucial interface between the human user and an electrical device. There are thousands of types of connectors that come in a broad range of sizes and shapes for various devices and purposes.
Certain complicated assemblies combine printed circuit boards soldered to fine wires that must be sealed in a plastic housing to protect them. To do this, overmolding is used. During the overmolding process, low-melting-temperature plastic is slowly pressed over the entire assembly and then cooled, forming a single block to protect the connection. In this sense, the overmolding process could be considered a combination of die casting and plastic injection molding. This is a one-time process, meaning the connector can never be opened again without destroying it, but it is a robust and reliable option when done correctly.
Finally, when wires, terminals, connectors, and overmoldings, or any combination of the four, are bundled together, it is known as a harness. These are common under the hood of cars, where the engine, battery, air compressor, etc. are all connected together through a series of different wires. Harnesses are custom engineered for a wide array of applications.
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