Power, power adapter

The laptop is powered by two ways, namely, the main power via a power adapter and batteries. Both are essential notebook accessories.

Supplying power to the laptop

Main Power supply
The computer power supply unit converts 110 Volts or 230 Volts AC (Alternating Current) power from the mains to low-voltage DC (Direct Current) power (less than 20 Volts) for the delicate electronic computer chips to work. These power supply units are built-in desktops; however, in notebook computers, they need to convert this power from AC to DC or to low voltage DC to medium voltage DC, outside the notebook computer by means of adapters.

Power adapters
There are two basic kinds of power adapters. AC adapters and DC adapters. Both types of adapters have connector plugs that exactly match the shape and size of the power receptacle in the notebook. The laptop notebook has specific input range measured in volts, amps, and/or watts, which the power output of the adapter matches.

Using an AC to DC Adapter.
These convert the AC power that comes from the wall socket to low-voltage DC power that the laptop uses. They are also called as chargers, because they can charge the internal laptop battery. They have a special connector which plugs into the laptop on one end, and an electric plug for the wall socket at the other end.

Input 100-240v AC 50/60Hz
Output 15v, 16v, 17v, 18v, 20v and 22v DC at 2.5amps
Short circuit and overload protection.
Up to 40% smaller and lighter than other chargers for easy portability
Powers and charges virtually all notebook computers from any AC or DC source
Provides the right power for iPods, cell phones, DVD players, and PDAs
120 watts--enough to power and charge larger, high-performance notebooks
An ideal replacement or upgrade for your existing power supply
Includes multiple tips for use with major-brand notebooks
Works with most Dell, HP, Compaq, Sony, Toshiba, IBM, Gateway, Averatec
Weight 6oz lbs.
5.6"L X 0.66"H X 3.1"W
1-Year warranty

Using a DC to DC Adapter.
These convert the DC power that comes from the auto batteries, in-flight power systems, and solar power systems to DC voltage that can be used by the laptop. At one end they have a special connector that connects to the laptop and at the other end, they have a DC input plug like a cigarette lighter plug. Laptop batteries can be recharged by this adapter either in aut or in-flight systems while using the laptop.

Input 11 – 15 Volts
Output V (out) - 15V, 16V, 18V, 19V, 20V, 21V (Volts) slide switch selectable
Output P (out) - 82 Watts
EMI - Compliant to FCC/VDE level B
Approvals - CE Mark
Mechanical - 92 x 58 x 40 mm (3 7/8 x 2 1/4 x 1 1/2 inches)
Weight - 255 grams (9 oz)
Connector, multiple connector kit for laptops including:
6.3 (OD) x 3.0 (ID) mm
5.5 (OD) x 2.5(ID) mm
5.0 (OD) x 2.1 (ID) mm
4.75 (OD) x 1.7 (ID) (ID) mm
6.5 (OD) x 4.3 (ID) x 1.4 (PIN) mm

Battery power supply
The notebook computer, depending on the make and type can have any one of the following batteries as a source of power while on the move or when the main supply is not available.

Alkaline (Zn/MnO2) batteries.
Nickel-cadmium (NiCd) batteries.
Nickel metal hydride (NiMH) batteries.
Lithium ion (Li-Ion) batteries. Latest notebook computers use Li-Ion batteries, which are found in many sizes.