Electric strike

According to the type of control electric signal, the electric strike includes:

• Direct current (DC)
• Alternating current (AC)
• Universal (AC / DC)

The supply voltage can vary and usually ranges from 6 to 48 V.

In terms of fail-safety, electric latches are divided into normally closed (fail-secure) and normally open (fail-safe). Fail-safe are normally-open electro-latches.

Normally Closed

Unlocking the normally-closed electrolatch mechanism occurs when an electrical signal is applied. Such electric latches are not allowed to be used on evacuation routes, since they are not fail-safe .

According to the type of control electric signal, the electric latches are divided into potential and pulse:

• the potential mechanism goes into the open state and remains in it when there is a control voltage and is automatically blocked immediately after the voltage is removed.

• the holding mechanism (arresting, pulsed) is unlocked and goes into the open state when the control signal is briefly supplied, remaining in the open state even after its removal. It is realized with the help of a locking pin , which, after removing the voltage, is pressed and held by an oblique crossbar, leaving the electric latch in the unlocked state. To bring the mechanism into a normal closed state, it is necessary to open and close the door, and only after that the mechanism will be locked. Such an unsafe algorithm for the operation of the electric latch may be necessary in pulsed door control systems.

In a number of normally closed models, the “constantly open door” mode is provided, that is, the “hold open” function is implemented, which allows a fixed mechanical unlocking of the latch. It is a small two-position lever for switching modes.

Normally Open

A normally-open mechanism is used to build emergency exits, vestibule locks and other fail-safe passages where unlocking is required when the power is turned off. In the presence of an electric signal, the latch mechanism and, accordingly, the door are locked. In the absence of a control signal, the door remains open. Thus, the normal-open latch operation algorithm is similar to an electromagnetic lock . Additional security can be provided by the door status monitoring function.

• Unlock function or “Manual unlock” ( Eng. Hold Open ). Convenient for occasional need to keep the door unlocked, for example, with high traffic. Do not use on fire doors that prevent the spread of fire.

• Hold function or "Catch". If a normally closed electrical latch is unlocked by a short-term pulse, then this mechanism holds it open until the door is opened.

• Status monitoring or feedback function with oblique bolt of the lock. Usually indicated by the abbreviation RR for it. Riegel Rückmeldung . When the door is closed, the lock bolt presses on a special platform, which signals the "door is closed" state. An electrolatch with this function usually has a slightly longer length due to an extra pad with output contacts C, NO, NC.

• Radial (rounded, radial, English Radius ). The turntable has a rounded profile and rotates to a smaller angle, so that it is recessed inward, the dimensions of the electric latch do not increase when the door is opened, which means a smaller cutout in the profile of the door frame is required.

• The adaptation function ( Easy Adapt ) eliminates the need to make a cutout in the door frame to the exit of the oblique crossbar, which gives protection against breaking the door and significantly improves the appearance. It is a beveled stationary platform along which the crossbar slides when the door is opened, rising above the profile of the door frame.

• Door frame
• Door furniture
• Door knob
• Lock bolt
• Mechanical door closer

• http://www.secuteck.ru/articles2/sys_ogr_dost/vidi-elektromehanicheskih-zamkov
• Electromechanical locks and latches