Electronics Components

Electronics components can be placed into two general categories, Active and Passive components. Active electronics components include semiconductors (solid state devices) and thermionic valves (vacuum tubes) and they have gain or directionality.

Passive components do not have gain or directionality and can be called electrical components or elements, it includes resistors, capacitors, filters, inductors and oscillators. There are also Electro-Mechanical Components that have a physical moving element eg switches, relays, motors and connectors.

This overview guide will increase your knowledge by helping you to understand the various uses of basic electronics components.

Switches
Switches are mechanical devices that are used to enable/disable the electrical flow around an electrical circuit at will.

Resistors
Resistors are two-terminal components that oppose an electric current by producing a voltage drop between it's terminals. It's purpose is to control or limit the flow of current.

Capacitors
Capacitors store electrical charge, it is essentially two conductive plates, separated by an insulator (the dielectric).

Diodes
Diodes are devices to let the current only flow in one direction. They are two terminal devices named the Anode and Cathode. Current will only flow when the anode is at a more positive voltage than the cathode.

Transistors
Transistors are used for two two basic functions: switching and modulation, the latter often used to achieve amplification. Transistors are made of semi-conductors such as silicon and gallium arsenide. These materials carry electricity moderately well-not well enough to be called a conductor, like copper wires; not badly enough to be called an insulator, like a piece of plastic, hence the name 'semi-conductor'.

Relays
Relays are an electromechanical device which are actuated by en electrical current. The current flowing in a circuit causes the opening or closing of another circuit.

Batteries
Batteries or cells are chemical stores of energy.

Thyristors
Thyristors operate in a similar way to a transistor but stay ‘switched on’ once the trigger voltage, has been removed.

Thermistors, LDR's, Reed Switches etc
These are used as sensors to be sensitive to particular conditions eg Thermistors are sensitive to thermal conditions, Light Dependent Resistors (LDR's) are sensitive to light, Reed Switch magnetic fields and Moisture Sensors etc

There are many hundreds of different types of electronics components, you can find out more from many useful websites.