Types
Mechanical keycard locks employ detainers which must be arranged in pre-selected positions by the key before the bolt will move. This principle was the base for the first known mechanical holecard operated lock, the VingCard, invented by Tor Sørnes. This was a mechanical type of lock operated by a plastic key card with a pattern of holes. There were 32 positions for possible hole locations, giving up to different keys. The key could easily be changed for each new guest by inserting a new key template in the lock that matched the new key.
In the early 1980s the key card lock was electrified with LEDs that detected the holes.
Magnetic strip (sometimes "stripe") based keycard locks function by running the magnetic strip over a sensor that reads the contents of the strip. The strip's contents are compared to those either stored locally in the lock or those of a central system. Some centralized systems operate using hardwired connections to central controllers while others use various frequencies of radio waves to communicate with the central controllers. Some have the feature of a mechanical (traditional key) bypass in case of loss of power.
Some models of card locks used in hotels use batteries and when the batteries fail the lock will fail safe meaning the lock stays open and therefore the door can be opened without the keycard. It may be possible to set this to fail secure meaning when the power is out the lock stays locked.
Read more about this topic: Keycard Lock
Famous quotes containing the word types:
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—Michael Blankfort. Lewis Milestone. Johnson (Reginald Gardner)
“Our children evaluate themselves based on the opinions we have of them. When we use harsh words, biting comments, and a sarcastic tone of voice, we plant the seeds of self-doubt in their developing minds.... Children who receive a steady diet of these types of messages end up feeling powerless, inadequate, and unimportant. They start to believe that they are bad, and that they can never do enough.”
—Stephanie Martson (20th century)
“Science is intimately integrated with the whole social structure and cultural tradition. They mutually support one other—only in certain types of society can science flourish, and conversely without a continuous and healthy development and application of science such a society cannot function properly.”
—Talcott Parsons (1902–1979)