The power adapter box does several things. It lowers the voltage from the wall's 120 volts AC to typically 19 volts DC (it will be labeled with the exact voltage). It includes some power noise filtering. It often includes an automatic circuit breaker or overload detection. If this gets tripped, you can generally reset it if you unplug it from everything for a few minutes.
The most common type of AC power adapter involves a small box, with one wire to go to the computer and another wire to go to the wall. There is usually an LED light on it, to tell you that it is on. (Is it lit on yours?) By the way, Apple notebook power adapters often have an LED that is actually built into the side of the computer, not into the adapter box, so obviously it won't light up when it's not connected to the computer.
Batteries, given their chemical nature, are prone to wear, corrosion, leakage and outright failure due to events like short circuits and LIGHTINING STRIKES. Given their propensity to fail and to have decreased performance over time, it is important to be able to identify and monitor their performance. With BatteryMon, monitoring the state of your battery has never been easier. BatteryMon is an easy to use Windows program that allows the monitoring of laptop computer batteries and uninterruptible power supplies (UPS). Graphically see the battery charge / discharge rate, diagnose problem battery cells, compare your batteries performance with expected discharge rates and see the status of each individual battery pack (when multiple batteries are in use).
For those of you with circular connectors, your task is easy. Measure the voltage between the inside and the outside. A diagram on the adapter's label will tell you which should be positive and negative
Answered by
shepherd
, an ibibo Master,
at
9:17 AM on April 16, 2008