A fluorescent lamp, or fluorescent tube, is a low-pressure mercury-vapor gas-discharge lamp that uses fluorescence to produce visible light. An electric current in the gas excites mercury vapor, which produces short-wave ultraviolet light that then causes a phosphor coating on the inside of the lamp to glow. A fluorescent lamp converts electrical energy into useful light much more efficiently than an incandescent lamp, but is less efficient than most LED lamps. The typical luminous efficacy of fluorescent lighting systems is 50–100 lumens per watt, several times the efficacy of incandescent bulbs with comparable light output. For comparison, the luminous efficiency of an incandescent bulb may only be 16 lumens per watt.
Mains electricity or utility power, grid power, domestic power, and wall power, or, in some parts of Canada, hydro, is a general-purpose alternating-current (AC) electric power supply. It is the form of electrical power that is delivered to homes and businesses through the electrical grid in many parts of the world. People use this electricity to power everyday items by plugging them into a wall outlet.
A neon lamp is a miniature gas-discharge lamp. The lamp typically consists of a small glass capsule that contains a mixture of neon and other gases at a low pressure and two electrodes. When sufficient voltage is applied and sufficient current is supplied between the electrodes, the lamp produces an orange glow discharge. The glowing portion in the lamp is a thin region near the cathode; the larger and much longer neon signs are also glow discharges, but they use the positive column which is not present in the ordinary neon lamp. Neon glow lamps were widely used as indicator lamps in the displays of electronic instruments and appliances. They are still sometimes used for their electrical simplicity in high-voltage circuits.
A power cord, line cord, or mains cable is an electrical cable that temporarily connects an appliance to the mains electricity supply via a wall socket or extension cord. The terms are generally used for cables using a power plug to connect to a single-phase alternating current power source at the local line voltage. The terms power cable, mains lead, flex or kettle lead are also used. A lamp cord is a light-weight, ungrounded, single-insulated two-wire cord used for small loads such as a table or floor lamp.
An earth-leakage circuit breaker (ELCB) is a safety device used in electrical installations with high Earth impedance to prevent shock. It detects small stray voltages on the metal enclosures of electrical equipment, and interrupts the circuit if a dangerous voltage is detected. Once widely used, more recent installations instead use residual-current devices which instead detect leakage current directly.
An isolation transformer is a transformer used to transfer electrical power from a source of alternating current (AC) power to some equipment or device while isolating the powered device from the power source, usually for safety reasons or to reduce transients and harmonics. Isolation transformers provide galvanic isolation; no conductive path is present between source and load. This isolation is used to protect against electric shock, to suppress electrical noise in sensitive devices, or to transfer power between two circuits which must not be connected. A transformer sold for isolation is often built with special insulation between primary and secondary, and is specified to withstand a high voltage between windings.
An antifuse is an electrical device that performs the opposite function to a fuse. Whereas a fuse starts with a low resistance and is designed to permanently break or open an electrically conductive path, an antifuse starts with a high resistance--an open circuit--and programming it converts it into a permanent electrically conductive path. This technology has many applications. Antifuses are best known for their use in mini-light style low-voltage Christmas tree lights.
A plasma ball, plasma globe, or plasma lamp is a clear glass container filled with noble gases, usually a mixture of neon, krypton, and xenon, that has a high-voltage electrode in the center of the container. When voltage is applied, a plasma is formed within the container. Plasma filaments extend from the inner electrode to the outer glass insulator, giving the appearance of multiple constant beams of colored light. Plasma balls were popular as novelty items in the 1980s.
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. Discrete circuits are made of individual electronic components that only perform one function each as packaged, which are known as discrete components, although strictly the term discrete component refers to such a component with semiconductor material such as individual transistors.
A cable tester is an electronic device used to verify the electrical connections in a signal cable or other wired assembly. Basic cable testers are continuity testers that verify the existence of a conductive path between ends of the cable, and verify the correct wiring of connectors on the cable. More advanced cable testers can measure the signal transmission properties of the cable such as its resistance, signal attenuation, noise and interference.
An earthing system or grounding system (US) connects specific parts of an electric power system with the ground, typically the equipments conductive surface, for safety and functional purposes. The choice of earthing system can affect the safety and electromagnetic compatibility of the installation. Regulations for earthing systems vary among countries, though most follow the recommendations of the International Electrotechnical Commission (IEC). Regulations may identify special cases for earthing in mines, in patient care areas, or in hazardous areas of industrial plants.
The Pearson–Anson effect, discovered in 1922 by Stephen Oswald Pearson and Horatio Saint George Anson, is the phenomenon of an oscillating electric voltage produced by a neon bulb connected across a capacitor, when a direct current is applied through a resistor. This circuit, now called the Pearson-Anson oscillator, neon lamp oscillator, or sawtooth oscillator, is one of the simplest types of relaxation oscillator. It generates a sawtooth output waveform. It has been used in low frequency applications such as blinking warning lights, stroboscopes, tone generators in electronic organs and other electronic music circuits, and in time base generators and deflection circuits of early cathode-ray tube oscilloscopes. Since the development of microelectronics, these simple negative resistance oscillators have been superseded in many applications by more flexible semiconductor relaxation oscillators such as the 555 timer IC.
A solenoid voltmeter is a specific type of voltmeter electricians use to test electrical power circuits. It uses a solenoid coil to attract a spring-loaded plunger; the movement of the plunger is calibrated in terms of approximate voltage. It is more rugged than a D'arsonval movement, but neither as sensitive nor as precise.
A touch switch is a type of switch that only has to be touched by an object to operate. It is used in many lamps and wall switches that have a metal exterior as well as on public computer terminals. A touchscreen includes an array of touch switches on a display. A touch switch is the simplest kind of tactile sensor.
In electrical safety testing, portable appliance testing is a process by which electrical appliances are routinely checked for safety, commonly used in the United Kingdom, Ireland, New Zealand and Australia. The formal term for the process is "in-service inspection & testing of electrical equipment". Testing involves a visual inspection of the equipment and verification that power cables are in good condition. Additionally, other tests may be done when required, such as a verification of earthing (grounding) continuity, a test of the soundness of insulation between the currentcarrying parts, and a check for any exposed metal that could be touched. The formal limits for a pass/fail of these electrical tests vary somewhat depending on the category of equipment being tested.
Stray voltage is the occurrence of electrical potential between two objects that ideally should not have any voltage difference between them. Small voltages often exist between two grounded objects in separate locations by the normal current flow in the power system. Contact voltage is a better defined term when large voltage appear as a result of a fault. Contact voltage on the enclosure of electrical equipment can appear from a fault in the electrical power system, such as a failure of insulation.
A fault indicator is a mechanism that conveys an indication of a fault, or absence of it, in a system. For example, the purpose of the engine-check light commonly found on the dashboard of motor vehicles is to indicate whether or not there is a fault with the engine.
An electrical outlet tester, receptacle tester, or socket tester is a small device containing a 3-prong power plug and three indicator lights, used for quickly detecting some types of incorrectly-wired electrical wall outlets or campsite supplies.
In electrical engineering, capacitive sensing is a technology, based on capacitive coupling, that can detect and measure anything that is conductive or has a dielectric constant different from air. Many types of sensors use capacitive sensing, including sensors to detect and measure proximity, pressure, position and displacement, force, humidity, fluid level, and acceleration. Human interface devices based on capacitive sensing, such as touchpads, can replace the computer mouse. Digital audio players, mobile phones, and tablet computers will sometimes use capacitive sensing touchscreens as input devices. Capacitive sensors can also replace mechanical buttons.
A tube tester is an electronic instrument designed to test certain characteristics of vacuum tubes. Tube testers evolved along with the vacuum tube to satisfy the demands of the time, and their evolution ended with the tube era. The first tube testers were simple units designed for specific tubes to be used in the battlefields of World War I by radio operators, so they could easily test the tubes of their communication equipment.
