LVDT/LVIT Case Study

Repeatability Reliability

A world leader in precision electro mechanical assemblies came to us looking for a high volume supplier to provide measurement feedback for bills passing between rollers in an ATM Machine. As the ATM can be used hundreds of times during the course of a day, repeatability and reliability was extremely important.

A typical bill measures 0.0003” (0.0075mm) the solution had to eliminate the risk of passing an unexpected number of bills while compensating for any dirt accumulation on the rollers that could cause inaccuracy.

We determined that an AC-operated LVDT would provide the optimal solution where by bills passing between the rollers could displace the LVDT core causing the output to change according to their thickness.

Any zero-offset value is stored and, then, compared against the LVDT output as the customer’s currency is measured, eliminating the risk of passing multiple bills while at the same time compensating for any variation of the roller surfaces.

We produced hundreds of thousands of these LVDT’s to support a 24/7 schedule at our customers facility, precise accurate feed back with high volume manufacturability.