Terminal (electronics)

For other uses, see Terminal (disambiguation).

"Pole (electrical circuits)" redirects here. For the poles of switches, see Switch § Contact terminology.

A terminal is the point at which a conductor from a component, device or network comes to an end.^[1] Terminal may also refer to an electrical connector at this endpoint, acting as the reusable interface to a conductor and creating a point where external circuits can be connected.^[2][3] A terminal may simply be the end of a wire or it may be fitted with a connector or fastener.^{[citation needed]}

Terminal symbol

A terminal strip, to which wires can be soldered

In network analysis, terminal means a point at which connections can be made to a network in theory and does not necessarily refer to any physical object. In this context, especially in older documents, it is sometimes called a pole. On circuit diagrams, terminals for external connections are denoted by empty circles.^[4] They are distinguished from nodes or junctions which are entirely internal to the circuit and are denoted by solid circles.^[5]

All electrochemical cells have two terminals (electrodes) which are referred to as the anode and cathode or positive (+) and negative (–). On many dry batteries, the positive terminal (cathode) is a protruding metal cap, and the negative terminal (anode) is a flat metal disc (see Battery terminal). In a galvanic cell such as a common AA battery, electrons flow from the negative terminal to the positive terminal, while the conventional current is opposite to this.^[6]

Types of terminals

• Connectors
• Line splices
• Terminal strip, also known as a tag board or tag strip
• Solder cups or buckets
• Wire wrap connections (wire to board)
• Crimp terminals (ring, spade, fork, bullet, blade)
• Turret terminals for surface-mount circuits
• Crocodile clips
• Screw terminals and terminal blocks
• Wire nuts, a type of twist-on wire connector
• Leads on electronic components
• Battery terminals, often using screws or springs
• Electrical polarity

See also

• Electrical connector – many terminals fall under this category^{[citation needed]}
• Electrical termination – a method of signal conditioning^{[citation needed]}

References

1. Davis, Larry (4 January 2012). "Definitions of Technical Terms - 'T' to 'Ter'". Electronic Engineering Dictionary. Retrieved 1 July 2019.
2. Connectors - Technologies and Trends (PDF). ZVEI - German Electrical and Electronic Manufacturers’ Association. August 2016. p. 51.
3. Barach, John. "Terminal definition by Babylon's free dictionary". Babylon NG. terminal n 2. Archived from the original on 1 July 2019.
4. "Circuit Symbols for Wires, Cables, Switches, Connectors". Electronics Notes. Retrieved 1 July 2019.
5. Electronics Symbols Handbook (PDF). Cleveland Institute of Electronics. p. 6. Retrieved 1 July 2019.
6. "An introduction to redox equilibria". Chemguide. Retrieved 4 July 2019.