ID TECH VP3300 OEM User Manual
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Figure 2: Standard Magnetic head assembly showing tolerances of Azimuth
4.2.
Reference Surface/Wear-Plate
The reference surface is an important element for the proper design of all credit card readers because
all dimensions for installing magnetic heads are measured from that surface. There are important
considerations to understand when designing the reference surface/wear-plate:
1.
ID TECH uses stainless steel for the reference surface/wear-plate in most of our credit
readers to prevent any measurable wear from the pressure exerted by card edges,
assuring negligible wear. Integrators should remember that the magnetic head’s
installation dimensions are taken from the reference surface and that any variation from
those dimensions could have a negative effect on reading reliability.
Note that electrostatic discharge can be an issue for MagStripe readers. When using metal
for the reference surface/wear-plate, integrators should either ground the plate or use
conductive plastic to help minimize ESD.
2.
ID TECH uses wear-resistant 30% glass-filled plastics in applications where stainless steel
is impractical, such as insert readers. In this type of reader, the force from the card’s edges
is small while inserting and withdrawing cards compared to the force exerted on the wear
plate in a conventional swipe reader. ID TECH’s insert readers use a 30% glass-filled
polycarbonate plastic in the insert reader’s rails.
3.
It is extremely important that the reference surface not have any bumps or abrupt changes
on the surface for
one card length
(3 and 3/8 inches) from the centerline of the read head’s
gap; any irregularities will cause reading failures. The critical design requirement is that the
reference surface/wear-plate must be at minimum flush to above any surface within a
card length of the read head’s center line. Any surface that is in-line with the card swipe, if
