In the block diagram of a cash machine, there are three separate units, the bill handling unit, coin handling unit, and the coin hopper. The bill and coin units have to align the currency for sensors to validate them as well as deliver them to the user. The coin hopper will return what has been input if the user pushes the return button. While some of these units are stand alone for making change, most of them are usually part of bigger machine like a snack or beverage dispenser. The standard power supply in these machines produces 24 volts and each of the units has multiple applications of 24 V motors.