Terminal (electronics)
A terminal is the point at which a conductor from a component, device or network comes to an end.<ref name="interfacebus">Davis, Larry (4 January 2012). "Definitions of Technical Terms - 'T' to 'Ter'". Electronic Engineering Dictionary. Retrieved 1 July 2019.</ref> 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.<ref name="zvei">Connectors - Technologies and Trends (PDF). ZVEI - German Electrical and Electronic Manufacturers’ Association. August 2016. p. 51.</ref><ref name="eng-dict">Barach, John. "Definition of Terminal". Dictionary of Automotive Terms. {{cite encyclopedia}}: |website= ignored (help)</ref> A terminal may simply be the end of a wire or it may be fitted with a connector or fastener.[citation needed]
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.<ref name="symbols">"Circuit Symbols for Wires, Cables, Switches, Connectors". Electronics Notes. Retrieved 1 July 2019.</ref> They are distinguished from nodes or junctions which are entirely internal to the circuit, and are denoted by solid circles.<ref name="symbols-handbook">Electronics Symbols Handbook (PDF). Cleveland Institute of Electronics. p. 6. Retrieved 1 July 2019.</ref>
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 . 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.<ref>"An introduction to redox equilibria". Chemguide. Retrieved 4 July 2019.</ref>
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
- Electrical termination - a method of signal conditioning
References
