7 ms·

He never explains why this actually happens. As a non-engineer, I'm curious why it's not immediate...

• jpm_sd 7y ago
  Nothing is perfectly stiff. Nothing moves perfectly smoothly. Every mechanical part has some amount of "springiness" and will vibrate when struck, pushed, flexed, etc. So a switch contact literally "bounces" like a hammer on a piano string as it is closed. His analogy of a ping-pong ball on a desk isn't great, but it's not exactly wrong, either. As for "immediate", the switch closure feels immediate to human perception (supposedly limited to about 1/20 second, for touch). But to modern electronics, nanoseconds are easily countable; and switch bounce can be measured in microseconds, or even milliseconds for a big, heavy electromechanical component. Here are some better articles. https://www.allaboutcircuits.com/technical-articles/switch-bounce-how-to-deal-with-it/ https://www.allaboutcircuits.com/technical-articles/switch-b... https://www.maximintegrated.com/en/design/technical-documents/app-notes/2/287.html https://www.maximintegrated.com/en/design/technical-document...
• cmroanirgo 7y ago
  A switch is a mechanical thing, obviously, that must have two metal plates touching one another fur electricity to flow. It takes time for one metal plate to move from position one to position two. So, while this switching is generally really fast, there is a period of time when the two metal plates are reeeally close, but not touching. Small bits of dust, grit and/or oxide on the metal can get in the way while the plates are really close, but not touching, causing electricity to flow, then not flow, then flow... Arcing can also happen when there's higher voltages used too. This happens a lot when you're using a push button, and also when you're switching on something that uses lots of current. You can actually hear the problem if you deliberately turn on your light switch really slow... The buzzing you hear is when electricity is arcing across the plates (wearing them out somewhat). It's not a problem for the light, but it's a huge problem for, say, a large pump.
• nerfhammer 7y ago
  when you move the switch contacts together or apart for a very brief moment they may literally bounce microscopically and make/break contact a few extra times
• roland35 7y ago
  Back in the day with big springy switches, the metal contacts would literally bounce off each other when turning on/off!