/ / Zippers
There are three different types in the market in terms of materials: brass, nickel, aluminum and plastic. Brass is the most conductive followed by nickel and aluminum.
How Resistors can be attached
This schematic shows a pull-down resistor. The circuit needs one because
when both sides of the zipper are separated,
the signal thread will loose the connection to the ground and give random values.
The slider itself has the perfect structure to connect two stitch
lines sewed in the opposite sides.
Though the zipper teeth are made out of plastic, usually sliders are made
of painted nickel. So by sanding the inside part of the slider body
where it holds the tape, the slider can tranfer the electricity
from one stitch to the opposite side one.
Red marks below are connecting parts between the thread and the slider.
A digital zipper sensor can be thought of as a multiple switch.
