Views: 197 Author: Site Editor Publish Time: 2021-08-13 Origin: Site
Rubber contact strip is also called as digital piano keypad rubber contact strips, which is typically used in Yamaha keyboard.There is conductive contact under the rubber contact strip, which will touch the digital piano’s PCB when press down the button of piano keyboard.This allows the keyboard and PCB to be connected, achieve a circuit, so that the digital piano can produce sound.
There are many conductive ways of silicone rubber keypad, such as carbon pills, conductive ink printing, metal pill, metal dome and nickel pill.We can call it contact point.
For digital piano keypad rubber contact strips, there are double conductive contact point. And you can see that, their contact height is different.
What does the double contact do?
When test actuation force of common silicone keypad, we can found that the graph is just a waveform (similar to parabola).When test the rubber contact strip of digital piano, there are two waveforms. This is because the rubber contact strip have double contacts and different heights.
Why do the digital piano rubber contact strip have such a design?
When presses down or presses to the bottom, the sound will present a heavy bass situation.
So the different rubber contact strip height is designed.
How to produce a good quality rubber contact strip?
-Rubber contact strip need to use high quality and high tensile silicone material, so that can achieve good rebound.
Note:The rubber contact strip cannot deform easily, cannot broke easily and should have good tensile.
-High precision compression mold is necessary.Rubber contact strip always have strict dimension requirements,and need low actuation force.So we need to use good-quality steel to manufacture the rubber contact strip mold.
-Conductive ink and conductive rubber carbon pills are used for rubber contacts.
Therefore, need to choose low resistance(less than 30 Ohms)conductive ink or carbon pill is effective.
-In addition to resistance, special attention should also be paid to the shape of conductive printing.Print too thick or too thin will affect the conductive sensitivity, so as to effect the sound of the piano.