Bill acceptors revolutionized vending machines in the late 1960s, simplifying soda and candy bar purchases. These devices authenticate currency for product dispensing. Modern vending machines, including those from various manufacturers, rely on advanced bill acceptor technology.
Early bill acceptors employed magnetic heads, similar to those in cassette players, to read the magnetic ink on banknotes. The Treasury’s high-content ink enabled this process, requiring direct contact between the magnetic heads and the bills. However, grime and lint often interfered with this process. Older machines were sometimes fooled by black and white photocopies of bills.
Today’s advanced magnetic readers hover above the bill’s surface, differentiating between copier ink and genuine Treasury ink. This is achieved by measuring the magnetic field and the pattern of magnetic particles within the ink, creating a unique ‘fingerprint’ for each bill.
Bill acceptor problems can arise, most notably poor acceptance rates. This occurs when the magnetic reader heads become worn, impairing their ability to read bills accurately. Preventative maintenance is crucial; regularly clean the bill acceptor with cotton swabs and alcohol.
If a vending machine accepts bills but fails to provide change, it indicates severely worn magnetic heads, necessitating servicing. Conversely, if the acceptor doesn’t pull in bills at all, it’s typically due to a faulty front sensor.
Proper maintenance is paramount. Each bill and coin leaves traces of ink and metal flakes, respectively. Periodically disassemble and clean the validator, focusing on the bill path, sensors, and belts. Inspect the belts for wear and tear. Consistent maintenance ensures the smooth and reliable operation of the vending machine’s bill acceptor.