Intrusion detector

Anti theft alarm: 1. Intrusion detector -- a device that turns the intrusion information on the protected site into electronic signals and transmits them to the outside. Commonly known as probe, also known as the front-end equipment of alarm. 2. Signal transmission part, also known as channel, is the external transmission channel of detector electronic signal. There are three main modes of transmission, i.e. wired, wireless, borrowing three different modes of transmission: wired transmission is also called special line transmission, i.e. using special wires, cables, optical cables to transmit alarm signals to other places. It has the advantages of strong anti-interference ability, anti-damage, short circuit and open circuit can be found immediately. The disadvantage is that the construction is troublesome. Wireless transmission will connect the intrusion detector with the wireless transmitter, once the alarm occurs, it will send a radio signal to the air. The wireless receiver receives the signal to generate an alarm, and informs the personnel for processing. It has the advantages of simple installation, strong mobility, multi-point transmission and one point reception, long control distance and large area. Its disadvantage is that it may be interfered by more powerful radio waves, lightning and other stray electric fields. The public lines such as telephone line, power line and cable TV network can be borrowed for alarm signal transmission. The advantages are easy construction and no special wiring. The disadvantage is that the ability to prevent damage is poor. 3. Anti theft alarm controller -- a device that can turn the electronic signal of intrusion information sent by intrusion detector into the acoustic and optical alarm signal and display, record and store it. Commonly used are table, cabinet, box and wall mounted. But it is necessary to produce alarm sound, display alarm position and store and record alarm informationYes. (2) intrusion detector point control type this is a series of intrusion detectors with small warning range and limited to local control. It is characterized by simple structure, stable operation, simple installation, low price, and its disadvantage is that the prevention is not strict enough. Magnetic switch intrusion detector magnetic switch intrusion detector: also known as magnetic control switch. It is composed of permanent magnet and reed. The dry reed, also known as the tongue reed, is constructed by encapsulating two or more soft iron electrodes in a sealed glass tube filled with inert gas. In the natural state, the two electrodes that are not in contact are called normally open type, and the ones that are in contact are called normally closed type. The normally open type is widely used. It is installed on the frame of the door or window. The electrode is connected with the controller by a wire, while the magnet is installed on the door or window sash. The door and window are closed, and the magnet is moved to make it just closed (when the magnet is close, the soft iron electrode is magnetized, and closed due to the attraction of the opposite sex). When the controller is opened, the door and window will enter the warning state (or fortification). At this time, the door and window will be opened again. As the magnet is far away from the reed, the electrode will be cut off automatically after loss of excitation, and the controller will give an audible and visual alarm. Because of the simple installation, the majority of residents can do it by themselves, and control the room door, balcony door and all windows. In addition to magnetic switch, such as micro switch, travel switch, mercury switch, pull switch can be used at the same time. All kinds of contact switches that can make the contact open under the external force and automatically reset after the external force disappears can be used together with the alarm controller. Using this principle, we usually call it switch alarm. This kind of alarm has a wide range of applicationsDifferent scale anti-theft systems are often used. But its disadvantage is that it is seldom used alone due to the lack of strict prevention area and parts and large loopholes. The glass breaking intrusion detector can be made by using the piezoelectric effect of piezoelectric ceramic sheet (the piezoelectric ceramic sheet will generate electric charge on its surface when it is distorted and deformed under the action of external force). Attach the detector to the glass of doors and windows, and connect the upper and lower surfaces to the control circuit with wires respectively. Once the glass is hit or broken by gravity, the piezoelectric effect will be generated. After the control circuit processing, the alarm will generate audible and visual alarm. The alarm is determined by the control circuit discrimination. The vibration caused by car passing, people walking, wind, etc. shall be eliminated. Only when the glass is hit can the alarm be given. This reduces the number of false alarms. Glass with different thickness and specifications can be used from tens of square centimeters to several square meters. When installing, pay attention to sticking firmly and reliably. If it is used with switch type alarm, the effect will be better. In the residential area, it is the most simple and practical anti-theft alarm system to connect the door lock control. The video image intrusion detector is in the field of view of the camera. The video alarm controller is used to set up the protection target, which is confirmed and then memorized. When the protection target is moved or new items are added, an alarm signal will be generated. The equipment is small and the size of items is unlimited, and can be increased or decreased at any time. It is very convenient to use. If the equipment is insufficient, the camera must be turned on, which will affect the service life. Touch inductive intrusion detectorThe electric film or metal wire will protect the safe, cultural relic cabinet or other valuables and exhibits. The alarm can be triggered when someone wants to touch it. In the family, we can set up defense at the balcony, guardrail, air conditioner outdoor unit, etc. once someone tries to climb, it will give an alarm. The inductive detector is mainly set up with metal wires, and the warning range can be expanded appropriately. For example, warning lines can be set up around cultural relics museums and Exhibition cabinets to prevent people from approaching and touching cultural relics exhibits. In case of any irregularity, the alarm sound will prompt the staff to stop it. The advantage of this product is flexible and flexible, the range can be large or small, the disadvantage is that the sensitivity should be adjusted frequently due to the influence of environmental humidity and temperature. Entry and exit control and access control system commonly used point control products various locks: key type, touch type electronic password lock; magnetic card lock; IC card lock; retina lock; fingerprint lock; voice lock, etc. Combination of electronic lock and mechanical lock. This kind of lock is installed on the door of the house. The door can be opened with a key at ordinary times. When the owner goes out to open the alarm, he will enter the warning state when the door is locked. Back home, the key to open the door, turn off the alarm. In the alert state, even if someone steals the key to open the door, but does not know the password, it cannot be disarmed, and an alarm will still be given after a few seconds. If you try to break the door and enter, you will immediately call the police. Building intercom security door: commonly used for public protection of unit building. Install electric control anti-theft door, door closer and control keyboard at the door of unit building. Any living room in the unit can enter the building with the key, and the door closer will automatically close the door. Visiting relatives and friendsThrough the control keyboard, after pressing the corresponding signal, the intercom in the master's room makes a sound. After the intercom confirms the identity, press the door lock open key to open the unit door, and invite the guests to enter. Irrelevant personnel can not be easily mixed in to ensure the safety of the unit. When going out, press the unlock key in the door to enter and exit freely. As long as a micro camera is installed on the control keyboard outside the unit door, the host can see the visitor through the LCD screen when talking, so as to prevent the villain from passing off. As early as the early 1990s, the security door was widely used in Guangzhou, Fujian, Hainan, Shenzhen and other coastal open cities, and the northern cities were also installed and used in succession. When using this kind of door, attention should be paid to whether there are people who do not know when opening the door to follow up intentionally. Once followed up, it will pose a threat to the safety of this unit. Other common point control alarm products pressure pad: put the cultural relics on the pressure pad and send out an alarm once they are taken away. Put a pressure pad under the carpet and an alarm will be generated when someone moves around. Put a pressure pad under the driver's seat, and someone who steals the car can call the police. It has a wide range of applications. Anti theft camera: it is linked with other intrusion detectors. Once someone is active in the prevention area, the camera takes photos continuously while alarming. The number of photos can be set in advance and can be used as a basis for solving a case. Automobile anti-theft alarm: smashing glass, opening door, stealing tire and starting car can cause alarm. You can call in the car, report to the pager, or report to the alarm center. When the police center receives the alarm, it can immediately send out to arrest the criminal; if it has already left, it can track down the robbery through the electronic map. 　　（3） Warning line control intrusion detector the intrusion detector is used to set up defense, forming an invisible warning line, which will alarm when someone passes through. Common are: active infrared, passive infrared, laser, microwave, induction and so on. The active infrared intrusion detector is composed of two parts: the active infrared transmitter and the receiver. Infrared light is in the spectral range invisible to the human eye. After focusing the beam, an infrared beam is formed between transceivers. Someone passing through this invisible blockade line must completely or partially block the infrared beam. The receiver will automatically recognize whether to alarm due to the change of infrared beam. If small animals, leaves, dust, rain, snow and fog are blocked, the alarm shall not be given. If people or objects of equivalent volume are blocked, the alarm will be given. It is used to block doors and windows in the factory warehouse, channel in the shopping center, exit in the parking lot and balcony in the home. Due to the narrow beam, the transmitter and receiver shall be installed firmly and reliably, which shall not be affected by the ground vibration, and the optical system shall be kept clean and pay attention to maintenance. The main difference between the structure of laser intrusion detector and active infrared detector is the light source. The infrared laser beam is narrow, not easy to diverge, and can form a blockade line of thousands of meters. When it is used in the exhibition hall, a set of devices can be used to form a four wall loop to block, so as to make the prevention more strict. Although there are many advantages, because the beam is thin and the mirror is afraid of displacement, it needs to be adjusted frequently in the use process to ensure the effectiveness. It is not suitable for home application due to its strong professionalism. The reflective passive infrared intrusion detector is made by installing a pyroelectric device in the middle of the front of a cylinder and a reflector at the bottom of the cylinder. Passive infrared radiation can be found in any object at room temperature. The higher the temperature, the stronger the infrared radiation. Man is a constant temperature animal, and infrared radiation is the most stable. The reason why we call it passive infrared is that the detector itself does not emit any energy but passively receives the infrared from the environment. After the detector is installed, it has adapted to the environment fingerprint home lock supplier for several seconds. Once there is infrared radiation from the human body, the pyroelectric components will generate sudden electrical signal and send out an alarm after being focused by the optical system. The warning line formed by passive infrared intrusion detector can reach tens of meters. It is easier to install than active infrared, but do not face the heat source and strong light source, especially the air conditioner and heating. Otherwise, the changing hot air flow will cause false alarm. The microwave (microwave wall) intrusion detector is a kind of electromagnetic wave, which can not be seen by human eyes. On the ground where the cordon is needed, the two ends of the transceiver are separated, and an invisible wall is formed between them. The wall is one meter thick and two meters high. When people walk through it, they will absorb or reflect the microwave, visit which makes the receiving terminal change the microwave energy greatly and cause an alarm. It is used to block passageways, counters and shelves in shopping malls and ammunition depots. It is very effective to block the gate and the river and lake in the villa area, and to block the balcony and the external window in the residence. But in the outdoor application, it must be noted that dogs or animals larger than dogs cross the blockade line to avoid false alarm. Inductive intrusion detectorThe detector is used to block the fish pond and all around the warehouse. It can form a ring warning line, which is very effective and convenient to use.