A relay is an electrically operated switch. It consists of a set of input terminals for a single or multiple control signals, and a set of operating contact terminals. The switch may have any number of contacts in multiple contact forms, such as make contacts, break contacts, or combinations thereof.
A soldering iron is a hand tool used in soldering. It supplies heat to melt solder so that it can flow into the joint between two workpieces.
In electrical engineering, a switch is an electrical component that can disconnect or connect the conducting path in an electrical circuit, interrupting the electric current or diverting it from one conductor to another. The most common type of switch is an electromechanical device consisting of one or more sets of movable electrical contacts connected to external circuits. When a pair of contacts is touching current can pass between them, while when the contacts are separated no current can flow.
An alternator is an electrical generator that converts mechanical energy to electrical energy in the form of alternating current. For reasons of cost and simplicity, most alternators use a rotating magnetic field with a stationary armature. Occasionally, a linear alternator or a rotating armature with a stationary magnetic field is used. In principle, any AC electrical generator can be called an alternator, but usually the term refers to small rotating machines driven by automotive and other internal combustion engines.
A circuit breaker is an electrical safety device designed to protect an electrical circuit from damage caused by current in excess of that which the equipment can safely carry (overcurrent). Its basic function is to interrupt current flow to protect equipment and to prevent fire. Unlike a fuse, which operates once and then must be replaced, a circuit breaker can be reset to resume normal operation.
A thermostat is a regulating device component which senses the temperature of a physical system and performs actions so that the system's temperature is maintained near a desired setpoint.
A cam timer or drum sequencer is an electromechanical system for controlling a sequence of events automatically. It resembles a music box with movable pins, controlling electrical switches instead of musical notes.
A timer or countdown timer is a type of clock that starts from a specified time duration and stops when reaching 00:00. A simple timer is an hourglass. Commonly, a timer triggers an alarm when it ends. A timer can be implemented through hardware or software. Stopwatches operate in the opposite direction, upwards from 00:00, measuring elapsed time since a given time instant. Time switches are timers that control an electric switch.
A bimetallic strip is a strip that consists of two strips of different metals which expand at different rates as they are heated. They are used to convert a temperature change into mechanical displacement. The different expansions force the flat strip to bend one way if heated, and in the opposite direction if cooled below its initial temperature. The metal with the higher coefficient of thermal expansion is on the outer side of the curve when the strip is heated and on the inner side when cooled.
A motor controller is a device or group of devices that can coordinate in a predetermined manner the performance of an electric motor. A motor controller might include a manual or automatic means for starting and stopping the motor, selecting forward or reverse rotation, selecting and regulating the speed, regulating or limiting the torque, and protecting against overloads and electrical faults. Motor controllers may use electromechanical switching, or may use power electronics devices to regulate the speed and direction of a motor.
In electronics and electrical engineering, a fuse is an electrical safety device that operates to provide overcurrent protection of an electrical circuit. Its essential component is a metal wire or strip that melts when too much current flows through it, thereby stopping or interrupting the current. It is a sacrificial device; once a fuse has operated, it is an open circuit, and must be replaced or rewired, depending on its type.
A kettle, sometimes called a tea kettle or teakettle, is a device specialized for boiling water, commonly with a lid, spout, and handle. There are two main types: the stovetop kettle, which uses heat from a hob, and the electric kettle, which is a small kitchen appliance with an internal heating element.
Induction cooking is performed using direct electrical induction heating of cooking vessels, rather than relying on indirect radiation, convection, or thermal conduction. Induction cooking allows high power and very rapid increases in temperature to be achieved: changes in heat settings are instantaneous.
An electronic component is any basic discrete electronic device or physical entity part of an electronic system used to affect electrons or their associated fields. Electronic components are mostly industrial products, available in a singular form and are not to be confused with electrical elements, which are conceptual abstractions representing idealized electronic components and elements. A datasheet for an electronic component is a technical document that provides detailed information about the component's specifications, characteristics, and performance.
A fan heater, also called a blow heater, is a heater that works by using a fan to pass air over a heat source. This heats up the air, which then leaves the heater, warming up the surrounding room. They can heat an enclosed space such as a room faster than a heater without a fan, but like any fan, create a degree of noise.
A thermal cutoff is an electrical safety device that interrupts electric current when heated to a specific temperature. These devices may be for one-time use, or may be reset manually or automatically.
A convection heater is a type of heater that uses convection currents to heat and circulate air. These air currents flow throughout the body of the appliance and across its heating element. This process takes advantage of thermal conduction in order to heat the air, reducing its density relative to colder air and causing it to rise.
A glow switch starter or glowbottle starter is a type of preheat starter used with a fluorescent lamp. It is commonly filled with neon gas or argon gas and typically contains a bimetallic strip and a stationary electrode. The operating principle is simple, when current is applied, the gas inside ionizes and heats a bimetallic strip which in turn bends toward the stationary electrode thus shorting the starter between the electrodes of the fluorescent lamp. After about a second the starter's bimetallic strip cools and opens the circuit between the electrodes, and the process repeats until the lamp has lit. One disadvantage of glow switch starters is that when the lamp is at the end of its life it will continuously blink on and off until the glow switch starter wears out or an electrode on the fluorescent lamp burns out. Glow starters have a relatively short life, and light fittings enable the starter to be changed easily. Electronic starters, being interchangeable and using the same casing as a glow starter, last for many years.
Overheating is a phenomenon of rising temperatures in an electrical circuit. Overheating causes damage to the circuit components and can cause fire, explosion, and injury. Damage caused by overheating is usually irreversible; the only way to repair it is to replace some components.
This glossary of electrical and electronics engineering is a list of definitions of terms and concepts related specifically to electrical engineering and electronics engineering. For terms related to engineering in general, see Glossary of engineering.
