A few things to consider when choosing a power supply. Many of our  products will work on both low 
voltage ac or dc and sometimes either 12 or 24 volts also . Always check on the item page-it will 
always tell you. A plug in transformer is the easiest way to apply power. If your doing a small system
meaning a single or two door system, plugins should be fine. If you'll be installing a larger system,
then try a multi terminal power supply. We have two types listed here -  4 and  5 terminal models. 
With these you'll find it easier to have all your power coming from in one source. The multi 
terminal models come from the factory with no AC plug. You can either wire them right into a 
circuit or it may just be easier to attach a plug and plug into an AC outlet. 
Don't forget when using magnetic 
locks that if the power fails there is no locking so order the backup battery option when using the multi-
terminal DC power supplies.
 See for power requirements
 See how to calculate voltage drop for long wire runs 
Caution: This may be more info than you want to know!