Well, according to The Art of Electronics by Horowitz & Hill (Page 506 of the Second Edition), “When the switch is closed, the two contacts actually separate and reconnect, typically 10 to 100 times over a period of about 1 msec.” This just goes to show you how undefined this field is, because this book is regarded as the “Electronics Bible” by many engineers, but their value of 1 msec (which is the one I was told as a young engineer) is less than Jack’s average findings, let alone his maximum findings.
In the Third Edition, on page 802, Horowitz and Hill write "For physically large switches, the bounce can be as long as 50ms." That first quote is from a section on clocked debouncing, which can be made insensitive to contact bounce by digital means.
I like the data sheet for the automotive contact debouncing IC.[1] That's very cute. In dirty environments, you need a minimum current and voltage, maybe 10mA, 12V, to punch through dirt and water on the contacts. That IC does that, but it only turns on the power intermittently, so you don't drain the battery polling the dashboard switches.
I've hit that with the antique Teletype machines. They were intended to run with 120VDC on the keyboard contacts, and you need about 24V or so to get reliable punch-through.
The Maxim's MAX6816/MAX6817/MAX6818[1] are pretty good as well in that you don't need RC filters for each input, so less components needed to debounce inputs.
In the Third Edition, on page 802, Horowitz and Hill write "For physically large switches, the bounce can be as long as 50ms." That first quote is from a section on clocked debouncing, which can be made insensitive to contact bounce by digital means.
I like the data sheet for the automotive contact debouncing IC.[1] That's very cute. In dirty environments, you need a minimum current and voltage, maybe 10mA, 12V, to punch through dirt and water on the contacts. That IC does that, but it only turns on the power intermittently, so you don't drain the battery polling the dashboard switches.
I've hit that with the antique Teletype machines. They were intended to run with 120VDC on the keyboard contacts, and you need about 24V or so to get reliable punch-through.
[1] https://www.ti.com/lit/ds/symlink/tic12400-q1.pdf