Double Detect On Friction System.

On Dispenser a mandatory sould have one sensor to detect money double or not and to check size of money correct or not. double detect commonly is the sensor work principle with light sensor or lvdt sensor(mechanicly system)
On this article we will talk about LVDT double detect on Dispenser with friction system. For illustration I will use dispenser old IBM series.


From Picture Above, we can see the Feed wheel assembly, this roller which this function roller is picking the money. Actualy the roller is not realy simetris rounded, but the eccentric. This mean the ecentric area will pick the money on the cycle of roller. Media on the picture is money.
The working this module is, when the money picking by eccentric roller of feed whell, the money will try to go inside small gap between Fork Block and Fork. When the money on gap, the fork mechanicly will move depend the thickness of money, and this will change the value of lvdt sensor by Proximity probe. The default value of lvdt set by double detect adjust screw. So if double money go inside, the value of LVDT will be out of range, and by dispenser control module , this is indicate the the double money happened on the feeding action.