"Door Magnetic Switch" in the security industry is generally used in anti-theft systems and access control systems, installed in the doors and windows of an intrusion detector. Security industry commonly known as "door magnet", security national standard CNCA-10C-047: 2009 "security technology to prevent the implementation of mandatory certification rules for the implementation of product certification intrusion detector products," the standard named "Magnetic Switch". Magnetic switch according to the type of supporting host is divided into wired door magnet and wireless door magnet, this paper does not talk about wireless door magnet.

1.0 Output signal of wired door magnet

Wired door magnet consists of reed switch and permanent magnet two parts, wired door magnet is basically compatible with all types of wired host, to achieve the intrusion detection of doors and windows. Door magnet is a switching signal, the door open and close triggered by the door magnet signal on and off, the door magnet output signal is divided into normally closed, normally open, and conversion type.

1.1 Normally Closed Door Magnet: When the door or window is normally closed, the permanent magnet and the reed switch are close to each other, and the magnetic field generated by the permanent magnet will absorb the contacts of the reed switch to form a closed state. If the door or window is opened illegally, the permanent magnet will be far away from the reed switch, and the magnetic field around the reed switch will disappear to cause the contacts to be disconnected, and the signal will be disconnected to trigger an alarm, which is usually called the disconnection alarm. Normally closed door magnet affordable, the market used the most.

1.2 Normally open door magnet: when the door or window is normally closed, the door magnet output signal is disconnected, when the door or window is opened illegally, the door magnet output signal is connected to trigger the alarm, called the pass-through alarm. The internal structure of the reed switch in the door magnet is more complex, the cost is also higher market use is relatively less.

1.3 conversion type door magnet: as the name suggests, the conversion type door magnet taking into account the characteristics of normally closed and normally open the door magnet, where it can be compatible with all the wired anti-theft alarm host.

2.0 wired door magnet installation

Wired door magnet installation is very simple, the reed switch partially installed in the fixed door frame, the magnet partially installed in the activities of the door window

2.1 Surface Mount Door Magnets

Surface mount door magnet is also called surface mount door magnet, general square wooden door magnet and metal door magnet can be surface mounted with double-sided tape and screws, the installation of the magnet and the reed switch part must be parallel alignment, if the installation has a misalignment may result in the switch sensing distance is reduced or can not be sensed. Commonly used models for surface mount wood door magnets are: 5C-31, 5C-37, 5C-38, 5C-44; Commonly used models for surface mount metal door magnets are: 5C-52, 5C-58, 5C-56, 5C-59.

Surface mount door magnets are relatively easy to install, the market is also the most used surface mount door magnets.

2.2 Embedded door magnet

Embedded door magnet is also called concealed door magnet, where the round door magnet is embedded door magnet, must be drilled to install, the same installation of magnets and reed switch part must be parallel alignment, if the installation of misalignment may cause the switch sensing distance is reduced or can not be sensed. Recessed wood door magnet commonly used models 5C-33, 5C-35; Recessed metal door magnet commonly used models: 5C-36

Embedded door magnet is characterised by more hidden, installation drilling is relatively more troublesome. Access control system door magnet selection is generally embedded door magnet, commonly used models: 5C-33B, 5C-36B

2.3 Rolling door magnet installation

General shops and garages commonly used rolling door magnet installation for buried type, reed switch department buried in the ground or ground, the magnet partially installed in the activities of the rolling door frame. Installation of the magnet and reed switch part must be parallel alignment, if the installation has a misalignment may cause the switch sensing distance is reduced or can not be sensed. Rolling door gap is generally larger, for safety reasons magnet part of the installation with adjustable bracket. Buried rolling door magnet commonly used models: 5C-55, 5C-55AL, 5C-61L

In Asia-Pacific Southeast Asian countries like to use the upper mounted rolling door magnet, representative model is: 5C-54