Mains electricity or utility power, power grid, 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 laptop computer or notebook computer, also known as a laptop or notebook for short, is a small, portable personal computer (PC). Laptops typically have a clamshell form factor with a flat panel screen on the inside of the upper lid and an alphanumeric keyboard and pointing device on the inside of the lower lid, although 2-in-1 PCs with a detachable keyboard are often marketed as laptops or as having a "laptop mode". Most of the computer's internal hardware is fitted inside the lower lid enclosure under the keyboard, although many laptops have a built-in webcam at the top of the screen and some modern ones even feature a touch-screen display. In most cases, unlike tablet computers which run on mobile operating systems, laptops tend to run on desktop operating systems which have been traditionally associated with desktop computers.
A power supply is an electrical device that supplies electric power to an electrical load. The main purpose of a power supply is to convert electric current from a source to the correct voltage, current, and frequency to power the load. As a result, power supplies are sometimes referred to as electric power converters. Some power supplies are separate standalone pieces of equipment, while others are built into the load appliances that they power. Examples of the latter include power supplies found in desktop computers and consumer electronics devices. Other functions that power supplies may perform include limiting the current drawn by the load to safe levels, shutting off the current in the event of an electrical fault, power conditioning to prevent electronic noise or voltage surges on the input from reaching the load, power-factor correction, and storing energy so it can continue to power the load in the event of a temporary interruption in the source power.
A jump start, also called a boost, is a procedure of starting a motor vehicle that has a discharged battery. A temporary connection is made to the battery of another vehicle, or to some other external power source. The external supply of electricity recharges the disabled vehicle's battery and provides some of the power needed to crank the engine. Once the vehicle has been started, its normal charging system will recharge, so the auxiliary source can be removed. If the vehicle charging system is functional, leaving the engine running will restore the charge of the battery.
A DC connector is an electrical connector for supplying direct current (DC) power.
IEC 60320 Appliance couplers for household and similar general purposes is a set of standards from the International Electrotechnical Commission (IEC) specifying non-locking connectors for connecting power supply cords to electrical appliances of voltage not exceeding 250 V (a.c.) and rated current not exceeding 16 A. Different types of connector are specified for different combinations of current, temperature and earthing requirements. Unlike IEC 60309 connectors, they are not coded for voltage; users must ensure that the voltage rating of the equipment is compatible with the mains supply. The standard uses the term coupler to encompass connectors on power cords and power inlets and outlets built into appliances.
In all fields of electrical engineering, power conversion is the process of converting electric energy from one form to another. A power converter is an electrical or electro-mechanical device for converting electrical energy. A power converter can convert alternating current (AC) into direct current (DC) and vice versa; change the voltage or frequency of the current or do some combination of these. The power converter can be as simple as a transformer or it can be a far more complex system, such as a resonant converter. The term can also refer to a class of electrical machinery that is used to convert one frequency of alternating current into another. Power conversion systems often incorporate redundancy and voltage regulation.
An adapter or adaptor is a device that converts attributes of one electrical device or system to those of an otherwise incompatible device or system. Some modify power or signal attributes, while others merely adapt the physical form of one connector to another.
IEC 60309 is a series of international standards from the International Electrotechnical Commission (IEC) for "plugs, socket-outlets and couplers for industrial purposes". They are also referred to as "pin & sleeve" connectors in North America or as "CeeForm" connectors in the entertainment industry. The maximum voltage allowed by the standard is 1000 V DC or AC; the maximum current, 800 A; and the maximum frequency, 500 Hz. The ambient temperature range is −25 °C to 40 °C.
An AC adapter or AC/DC adapter is a type of external power supply, often enclosed in a case similar to an AC plug. AC adapters deliver electric power to devices that lack internal components to draw voltage and power from mains power themselves. The internal circuitry of an external power supply is often very similar to the design that would be used for a built-in or internal supply.
A battery charger, recharger, or simply charger, is a device that stores energy in a battery by running an electric current through it. The charging protocol depends on the size and type of the battery being charged. Some battery types have high tolerance for overcharging and can be recharged by connection to a constant voltage source or a constant current source, depending on battery type. Simple chargers of this type must be manually disconnected at the end of the charge cycle. Other battery types use a timer to cut off when charging should be complete. Other battery types cannot withstand over-charging, becoming damaged, over heating or even exploding. The charger may have temperature or voltage sensing circuits and a microprocessor controller to safely adjust the charging current and voltage, determine the state of charge, and cut off at the end of charge. Chargers may elevate the output voltage proportionally with current to compensate for impedance in the wires.
MagSafe is a series of proprietary magnetically attached power connectors developed by Apple Inc. for Mac laptops. MagSafe was introduced on 10 January 2006, in conjunction with the MacBook Pro, the first Intel-based Mac laptop, at the Macworld Expo. A MagSafe connector is held in place magnetically so that if it is tugged, it will be pulled out of the port without damaging the connector or the port, and without pulling the computer off its surface. A thinner and wider version, called MagSafe 2, was introduced in 2012. It was discontinued across Apple's product lines between 2016 and 2019 and replaced with USB-C. MagSafe returned to Mac laptops with the introduction of updated MacBook Pro models with MagSafe 3 in 2021.
A voltage converter is an electric power converter which changes the voltage of an electrical power source. It may be combined with other components to create a power supply.
An automobile auxiliary power outlet in an automobile was initially designed to power an electrically heated cigarette lighter, but became a de facto standard DC connector to supply electrical power for portable accessories used in or near an automobile directly from the vehicle's electrical system. Such include mobile phone chargers, cooling fans, portable fridges, electric air pumps, and power inverters.
A USB decoration is a decorative device that uses the Universal Serial Bus (USB) connector for electrical power, and sometimes the protocol, on a computer or other host. In addition, some lightweight devices use the USB connector itself for mechanical support.
ISO 4165 is a standard adopted by the International Organization for Standardization (ISO) that describes a double-pole DC connector to supply between 12 and 24 V DC at up to 12 amps to appliances in vehicles. Although roughly similar in design to an automotive accessory receptacle, the ISO 4165 connector is shorter and smaller in diameter. It was originally a standard fitting on all the German military vehicles during World War II.
SAE J1772, also known as a J plug or Type 1 connector after its international standard, IEC 62196 Type 1, is a North American standard for electrical connectors for electric vehicles maintained by SAE International under the formal title "SAE Surface Vehicle Recommended Practice J1772, SAE Electric Vehicle Conductive Charge Coupler".
The Universal Power Adapter for Mobile Devices (UPAMD), codename IEEE 1823-2015, is an IEEE standard for power supply design intended to cater to the power range of 10–130 W for mobile devices like laptop computers. The power supply was required to have an output capacitive energy of less than 15.1 µJ and an inductive energy at disconnect of less than 5.3 µJ.
IEC Technical Specification 62700: DC Power supply for notebook computer is an IEC specification of a common standard for external laptop computer AC adapters. Laptops and AC adapters following this standard will have interchangeable power supplies, which will enable easy reuse of used power supplies and make buying a new compatible power supply for a laptop simpler.
The initial versions of the USB standard specified connectors that were easy to use and that would have acceptable life spans; revisions of the standard added smaller connectors useful for compact portable devices. Higher-speed development of the USB standard gave rise to another family of connectors to permit additional data paths. All versions of USB specify cable properties; version 3.x cables include additional data paths. The USB standard included power supply to peripheral devices; modern versions of the standard extend the power delivery limits for battery charging and devices requiring up to 240 watts. USB has been selected as the standard charging format for many mobile phones, reducing the proliferation of proprietary chargers.
