Ohmic sensing
Provided by the ASK Keyboard Dictionary
Also known as: conductive-contact sensing, contact-based sensing
Ohmic sensing is IBM's term for the simplest form of keyboard sensing and operates on the principle of registering keys when electricity sent through a circuit (such as a key-matrix) returns. This is a principle shared by most keyboards whether it is Alps SKCx/SKBx, Cherry MX, IBM membrane buckling springs or buckling sleeves, or rubber dome over membrane key-switches in question. As the aforementioned key-switches work by closing a circuit when two contacts are closed, this principle is more commonly referred to as contact-based or conductive-contact sensing. Keyboards that use ohmic sensing are known as contact-based keyboards or ohmic keyboards. It's believed that "ohmic" refers to Ohm's law as a whole (ie, operates on basic electric principles) rather than resistance or Ohms as a unit.
