How It Works
As can be seen from the diagram below, the membrane keyboard basically consists of three layers; two of these are membrane layers containing conductive traces. The center layer is a "spacer" containing holes wherever a "key" exists. It keeps the other two layers apart.
Under normal conditions, the switch (key) is open, because current cannot cross the non-conductive gap between the traces on the bottom layer. However, when the top layer is pressed down (with a finger), it makes contact with the bottom layer. The conductive traces on the underside of the top layer can then bridge the gap, allowing current to flow. The switch is now "closed", and the parent device registers a keypress.
Typical applications include;
- Industrial controls
- Access control systems
- Medical equipment
- Telecommunications apparatus
- Telephone systems
- Household appliances
- Security systems
Source, APEM, Membrane switch panels
Read more about this topic: Membrane Keyboard
Famous quotes containing the word works:
“There is a great deal of self-denial and manliness in poor and middle-class houses, in town and country, that has not got into literature, and never will, but that keeps the earth sweet; that saves on superfluities, and spends on essentials; that goes rusty, and educates the boy; that sells the horse, but builds the school; works early and late, takes two looms in the factory, three looms, six looms, but pays off the mortgage on the paternal farm, and then goes back cheerfully to work again.”
—Ralph Waldo Emerson (1803–1882)