PLC based change dispensing machines capable of identifying counterfeit currency using sensors

Abstract

Change dispensing vending machines are used to provide change to the user as per the denomination of
note given to the machine by the user. Change dispensing vending machine using PLC can be implemented using various
devices or techniques such as transistors, transducers, sensors and image processing technique. In this research paper
sensors are used with PLC for change dispensing machine. Counterfeit currency is the major problem associated with
change dispenser machine. To detect the counterfeit note and to identify its denomination various sensors are used as
detector. The outputs of the sensors are given to the PLC and the operation of PLC is programmed using ladder logic in
this paper.