A PDQ electric strike is an access control device used for doors. It replaces the fixed strike faceplate often used with a latch bar. Like a fixed strike, it normally presents a ramped surface to the locking latch allowing the door to close and would latch just like a fixed strike. However, an electric strike's ramped surface can pivot out of the way when the lock on the door is in the locked position and the door is opened, allowing a user to open the door without operating the mechanical lock or using a mechanical key. After the door is opened past the latch, it returns to its standard position and re-locks when power is removed or applied, depending upon the strike's configuration.
Electric strikes are sometimes equipped with buzzers that allow someone outside the door to hear when the door is open. The buzzing noise is typically made by applying alternating current to the strike instead of direct current. When using a DC powered strike, if desired a buzzer accessory can be added to create the buzzing noise.