How ATM (automated teller machine) count the notes ?

[kseng2002]

how does a machine count notes

Does any1 know how ATM (automated teller machine) count the notes ? What sensors does ATM use ? Any1 have any ideas ? Can provide any block diagram of it ? Thanks in advance.

 

[vamanan]

atm sensing thickness bill pdf

ATM's use LVDT(Linear variable differential transformer) for sensing the bills. They measure the thickness of the bill and detect if 2 or more bills stick together etc.
**broken link removed**

 

[cyberrat]

LVDT's - fiddlesticks!!

They have a little man inside them, he does all the counting & giving out of money.
If he does not like the look of you on his monitor he will keep your card & not let you have any money.

 

[kseng2002]

Hi, is it only LVDT ? No other sensor ? Thx in advance ~

 

[rikie_rizza]

Wow LVDT, I never realize that. So, if I bring a powerful magnet and place it near the sensor, would it mess the reading?
Must try!