What is an AC DC adapter?

Answer 1

Most electronic equipment runs on DC (direct current), while the power supplied at receptacles is AC (alternating current). Some electronic equipment contains a power supply internally that converts AC to the required DC. Other equipment requires an external adapter to convert.

When looking at an adapter it is important to get one that is compatible with the requirements of the equipment. The wrong adapter can damage equipment, or overheat. An adapter should be labeled with the following information.

1. check that the adapter input voltage matches your local power (i.e. 110-125VAC in US)

2. check that the adapter output voltage matches the equipment to be powered.

3. be sure the adapter output voltage is DC if the equipment requires DC--some adapters produce AC.

4. check that the adapter can supply at least as much current as the equipment requires. If it can supply more, that is fine. This will be in amps or more typically milliamps (mA) (for example it will say "200mA")

5. check that the connector on the adapter matches the input to the equipment-can it be plugged in?

6. important--even if the connectors mate, check that the polarity is the same. Unfortunately some commonly used power plugs are found wired both ways. For example, on round power connectors, sometimes the center is positive, sometimes it is negative.