Latch

Latch may refer to:

Technology

Other uses

See also

Flip-flop (electronics)

In electronics, a flip-flop or latch is a circuit that has two stable states and can be used to store state information. A flip-flop is a bistable multivibrator. The circuit can be made to change state by signals applied to one or more control inputs and will have one or two outputs. It is the basic storage element in sequential logic. Flip-flops and latches are a fundamental building block of digital electronics systems used in computers, communications, and many other types of systems.

Flip-flops and latches are used as data storage elements. A flip-flop stores a single bit (binary digit) of data; one of its two states represents a "one" and the other represents a "zero". Such data storage can be used for storage of state, and such a circuit is described as sequential logic. When used in a finite-state machine, the output and next state depend not only on its current input, but also on its current state (and hence, previous inputs). It can also be used for counting of pulses, and for synchronizing variably-timed input signals to some reference timing signal.

Latch (hardware)

A latch (called sneck in Northern England and Scotland) is a type of mechanical fastener that is used to join two (or more) objects or surfaces together while allowing for the regular or eventual separation of the objects or surfaces. A latch typically engages another piece of hardware on the other mounting surface. Depending upon the type and design of the latch, this engaged bit of hardware may be known as a keeper or strike. Note that a latch is not the same as the locking mechanism of a door or window, although often they are found together in the same product.

Latches range in complexity from flexible one-piece flat springs of metal or plastic, such as are used to keep blow molded plastic power tool cases closed, to multi-point cammed latches used to keep large doors closed.

Common types

Deadbolt latch

A single-throw bolt. The bolt can be engaged in its strike plate only after the door is closed. The locking mechanism typically prevents the bolt from being retracted by force.