Electric strike

An electric strike is an access control device used for doors. It replaces the fixed strike faceplate often used with a latchbar (aka a keeper). Like a fixed strike, it normally presents a ramped surface to the locking latch allowing the door to close and latch just like a fixed strike would. However, an electric strike's ramped surface can, upon command, pivot out of the way of the latch allowing the door to be pushed open (from the outside) without the latch being retracted (that is, without any operation of the knob) or while exited the knob or lever can be turned to allow egress from the secured area.

Electric strikes generally come in two basic configurations:

* Fail-secure. Also called Fail-locked or non-fail safe. In this configuration, applying electrical current to the strike will cause it to open. In this configuration, the strike would remain locked in a power failure, but typically the knob can still be used to open the door from the inside for egress from the secure side. These units can be powered by AC which will cause the unit to "buzz", or DC power which will offer silent operation, except for a "click" while the unit releases.

* Fail-safe. Also called Fail-open. In this configuration, applying electrical current to the strike will cause it to lock. In this configuration, it operates the same as a magnetic lock would. If there is a power failure, the door would open merely by being pushed/pulled open. Fail safe units are always run using DC power.

Electric strikes are sometimes equipped with buzzers which allow someone outside the door to hear when the door is open. The buzzing noise is typically simply a result of applying AC current to the strike instead of DC, keep in mind the "buzzing" varies depending on voltage, and the coil or solenoid, although the buzzing from the AC current is audible, it is not designed to be loud for everyone to 'hear'. If using DC voltage you would have to install a true buzzer if you want to "hear" the unit.

There are many manufacturers of strikes, and there are many things that have to be considered when buying one, i.e. type of jamb, type of locking hardware, whether you require fail secure or fail safe, length of latch, depth of jamb, voltage requirements and the length of the faceplate. In some cases it is better to go with a Magnetic lock