Winn L. Rosch Hardware Bible, Sixth Edition

Electrical Function

In the macroscopic world in which we live, switches operate positively without hesitation or doubt. Switch on a light, and it comes on like, well, a light. In the realm of microelectronics, however, switches are not so certain in their first steps toward changing state. As a switch makes contact, it hesitates, letting tiny currents flow and then halting them; then letting more flow. These initial jitters are called switch bounce, and they result from a number of causes. The contact materials of most switches are far from perfect. They may become coated with oxidation or other impurities, and they often don't mesh together perfectly. The contacts touch, bounce, cut through the crud, and finally mate firmly together. In the ...