Review the input and output voltage specifications for different AC to DC voltage converters on the market. Make sure the converter has an AC input voltage range that will accept a 110 AC voltage input. Also check if the output will produces a 12 volt DC signal or can be adjusted to 12 volt DC.
Examine the power efficiency specifications of different 110 volt AC to 12 volt DC voltage converters. If you are interested in saving electrical costs over the long run, choose a converter with a power efficiency between 85 and 95 percent. Converters that a lower power efficiency consume more electricity but usually cost less to purchase.
Compare the power factor correction specifications of the converters. Those with a power correction factor close to "one" are more energy efficient and will reduce energy consumption. Those with a lower power correction factor aren't as efficient but are usually less expensive.