Voltage

The Lenovo ThinkPad SL510 AC Adapter scales the 120 volts from your wall down to a voltage in the area of 6 to 18 volts using a small transformer. A transformer consists of two coils of wires interspersed around an iron core. By electromagnetic law, the ratio of the number of coil turns in one wire to the other will equal the ratio of the voltages in the two wires.

Rectifying

After converting the power to the desired voltage level, the adapter converts the AC to DC using a setup called a rectifier. The rectifier uses a combination of diodes, one-way electronic components, to make constant DC power from alternating Asus Z65R AC Adapter.

Example

A 12-volt adapter performs the following steps. First, the 120 volts of AC power from the wall goes into one end of the transformer, which has 10 coil windings on the input for every 1 on the output, and induces 12-volt AC power. Next, the AC power goes through a series of diodes and comes out as 12 volts DC, ready to power your laptop, your home telephone, or to charge your cellphone.

How to Attach an AC Adapter to a Battery Pack

Unlike desktop computers, which require an internal power supply to function, laptop computers use an internal battery pack and external power supply. The external power supply, or alternating current (AC) adapter, provides the computer a steady stream of electricity. The Asus Eee PC 1201N AC Adapter also recharges the battery pack installed inside the system so the laptop can temporarily run without needing electricity from a wall outlet.

Connect the power cord to the AC adapter. Insert the other end of the cord into an active power strip or wall outlet.

Insert the cable connected to the Dell XPS M1330 AC Adapter to the power jack located on the side or rear of the laptop. The AC adapter will begin charging the battery pack installed to the laptop.

Open the display lid. Press the "Power" button to turn on the laptop.