When purchasing a power adaptor for your electrical device, there are two general types: AC adaptors and DC adaptors. they may look very similar and have similar inputs and outputs, but their functions are very different ,so what's difference bettween AC and DC adapter ??
Alternating Current Adaptors
Alternating current (AC) is an electric current that reverses direction in a circuit at regular intervals. This means that the amount of current (measured in amperes, or amps) goes from positive to negative at a regular interval, Unless the AC adaptor changes the interval at which the current reverses direction, AC adaptors will only be rated at the input interval (such as 60 Hz for the United States).
Direct Current Adaptors
Direct current (DC) is an electric current flowing in one direction only.Therefore, the direct current remains flowing in a constant direction, with no changes in frequency or polarity (changing from positive to negative).
A DC adaptor differs from an AC adaptor in that the DC adaptor converts AC electricity into DC electricity. For example, a power adapter 12v sold in the United States will convert 120 V AC at 60 Hz into 12 V DC.Typically, your electronic device will tell you which type of electrical current is required. This will also be in the form of "12 V DC, 10 A" or "12 V AC, 10 A, 60 Hz