Signal and Low-Voltage Wire
Not every wire carries building power. Electronics uses conductors for audio, sensors, controls, data, radio frequency, instrumentation, alarms, networks, and communication. In these systems, shielding, capacitance, impedance, noise pickup, flexibility, and connector compatibility can matter more than ampacity.
Hook-up wire
Hook-up wire is general-purpose insulated wire used inside electronic equipment, control panels, prototypes, and assemblies. It may be solid or stranded and is available with PVC, cross-linked, fluoropolymer, silicone, or other insulation. The equipment standard and product marking determine its permitted voltage and temperature.
Twisted pair
Twisting two conductors makes external magnetic noise couple more equally into both wires. A differential receiver responds mainly to the difference between the conductors and rejects much of the common noise. This is why twisted pairs are used in Ethernet, serial communication, instrumentation, audio, and control systems.
Shielded cable
A conductive foil or braid around signal conductors can reduce electric-field and radio-frequency interference. Shield termination is part of the circuit: connecting it at one end, both ends, or through a controlled network can produce very different results depending on frequency, grounding, and system design.
Coaxial cable
Coaxial cable has a center conductor surrounded by dielectric and a concentric outer shield. Its geometry controls characteristic impedance and confines much of the electromagnetic field inside the cable. Common systems use impedances such as 50 or 75 ohms, but the correct value is determined by the equipment and application.
Characteristic impedance is not DC resistance
A 50-ohm coax cable does not measure 50 ohms end-to-end with an ordinary ohmmeter. Fifty ohms is its traveling-wave impedance at frequencies where the cable behaves as a transmission line. The copper conductor itself has a much smaller DC resistance.
Ribbon cable
Ribbon cable keeps many conductors in a flat, parallel arrangement. It is convenient for board-to-board connections and mass-termination connectors. Long parallel runs can also increase capacitive and magnetic coupling between signals, so ground conductors may be interleaved between fast signals.
Thermocouple and sensor wire
Some sensor wires are part of the measurement itself. Thermocouple extension wire, for example, uses specific alloys so unwanted junctions do not introduce large measurement errors. Substituting ordinary copper can change the reading.
Separation from power wiring
Low-voltage and communication wiring can be subject to code rules for separation, barriers, raceways, cable ratings, grounding, firestopping, plenum spaces, risers, and entry into buildings. The voltage may be low, but the wiring method still matters.
Flexible automation cable
Robots, cable carriers, gates, CNC machinery, and moving equipment may require cable rated for continuous flexing rather than merely “stranded” wire. Strand size, lay length, insulation, fillers, shields, and jacket construction are designed around millions of movement cycles.