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:
“As for types like my own, obscurely motivated by the conviction that our existence was worthless if we didn’t make a turning point of it, we were assigned to the humanities, to poetry, philosophy, painting—the nursery games of humankind, which had to be left behind when the age of science began. The humanities would be called upon to choose a wallpaper for the crypt, as the end drew near.”
—Saul Bellow (b. 1915)
“If there is nothing new on the earth, still the traveler always has a resource in the skies. They are constantly turning a new page to view. The wind sets the types on this blue ground, and the inquiring may always read a new truth there.”
—Henry David Thoreau (1817–1862)
“He’s one of those know-it-all types that, if you flatter the wig off him, he chatter like a goony bird at mating time.”
—Michael Blankfort. Lewis Milestone. Johnson (Reginald Gardner)