A buck converter is disclosed which prevents a voltage drop below a desired voltage when a load change occurs. In a preferred configuration, the scanner is integrated with a weigh scale for obtaining a dynamic weight of an item as the item is moved across the weigh scale. Information relating to the parameterizable components is embedded on the programmable chip by storing the information using mechanisms such as look up tables associated with logic elements. Preferably, the conveyor belt includes means for its rotation in a generally horizontal direction. A gap between the apparatus side terminal and an inner circumference of the apparatus side housing is sealed with a seal member which is externally fitted around the extension portion of the apparatus side terminal.