
ID TECH SecureHead SPI with TMIV User Manual
Page | 53
8.
The bottom of slot and the slot walls should not have any discontinuities and
must be flat (no deformation is allowed). The portion of the slot wall, about
10mm on each side of the magnetic head’s crown, should not have draft and
must be perpendicular to the bottom of slot (reference surface). The slot width in
lead-in and lead-out area shall be greater and must have gradual transition with
no edges, or angles to interfere with the smooth swiping of a card.
A.
Plane of Head Gap
B.
Plane of Slot Wall
9.
Depending on the requirement of swipe life cycles, a suitable material for the rail
shall be decided. If the life of the reader is to be greater than 50,000 passes, the
bottom of slot must embed a metal wear plate (stainless steel is the metal of
preference to avoid corrosion), or the plastic material used for the slot needs to
be significantly harder than the card material to ensure adequate rail life.
10.
The back side (pin side) of magnetic head shall have enough reserved space to
prevent interference with other parts during swiping of maximum thickness
cards. The design must provide for a minimum of 1.25~1.52mm space behind the
head to allow for proper gimbal and head movement during card swiping. The
head opening in the rail must allow room for maximum gimbal action.
11.
When the head is installed into the rail, the spring holding the head should be
slightly preloaded. Preloading the spring will ensure that the head has some
stability at the first impact with the card, which is important especially if the card
is swiped at high speed. (If the spring is not preloaded it will tend to vibrate when
the card impacts the head; vibration would cause head to lose contact with the
card.)
12.
ID TECH’s solution to preload the head spring is to add 2 symmetrical bumps one
on each side of the head (head window), molded into the rail (see drawing below).
We recommend that the difference between the spring resting surfaces and the
crown of the bumps is 0.06+/_0.03 mm, which for a head spring that is 0.20 mm