The wireless transmission method uses radio waves to transmit an alarm signal. The method needs to be equipped with a transmitter and a receiver, and the detector is connected to the transmitter. The detectors can be of various types. The wireless alarm system adopts the microcomputer coding control method, that is, the microcomputer automatic error detection and error correction technology improves the reliability and anti-interference of the wireless alarm system, but the transmission of the wireless signal is affected by the transmitter power, receiver sensitivity, terrain, The influence of building structure, etc., must be carefully debugged before installation and use, and interference signals of the same frequency or adjacent frequency should be avoided in the same area. At present, China's wireless alarm system is stipulated to use radio frequency 315MHZ or 433MHZ wireless transceiver circuit, often using hardware or software codec.
Since the wireless alarm does not require wiring, it not only saves the cost of the wire but also has a great installation advantage in the renovated house. The biggest disadvantage of wireless alarm is that it is poor in security and susceptible to interference. Like frequency interference, environmental interference. Moreover, domestic wireless hosts rarely do the problem of detecting the status of wireless detectors and battery life. It should be said that wireless alarms are relatively large. The wireless controllers of international famous brands will adopt multi-frequency communication, two-way communication and other technologies, and the safety and reliability can be greatly improved, but the price will also rise.
At present, people still have doubts about the stability of wireless signal transmission. For example, wireless product transmission is susceptible to such as lightning strikes and electromagnetic interference, which greatly reduces the stability of the signal. At present, the development of frequency hopping technology has greatly enhanced wireless. The anti-interference of the transmission, when the wireless signal is interfered, it will automatically hop to another channel, thus ensuring the stability of the wireless signal transmission. And the general civil security is much lower than the requirements of important institutions such as finance, so wireless security products can fully meet the needs of civil security.
For the stability and reliability of wireless signal transmission, there are foreign brands. For example, Israel's Agility wireless alarm system has taken corresponding measures:
1. Two-way wireless technology, confirming signal feedback: The traditional wireless detecting device has a defect, that is, after the current end detector detects the alarm sent to the controller, the controller successfully receives the alarm signal, neither of which is known. . Then, the two-way wireless acknowledgment technology of the Agility wireless alarm system can solve such problems. The front-end detector sends an alarm signal to the controller. When the alarm controller successfully receives the alarm signal, it will immediately return an acknowledgement signal to the front-end detector to ensure the correct transmission of the alarm signal. It can be said that the two-way wireless confirmation technology is in the alarm product. Not much to see.
2. Electromagnetic environment and detector status monitoring: With the increasing severity of wireless electromagnetic interference, the application environment becomes very complicated, which also hinders the application of wireless devices. The key problem is that traditional technologies cannot rely on environmental electromagnetic interference and front-end. The state of the wireless detector proposes corresponding technical countermeasures, so that the probability of the detector being affected by the environmental electromagnetic interference is increased, so that the strength of the wireless signal of the detector is weakened; in addition, the power of the detector battery is insufficient, and the system is not working properly. And affect the effective transmission of the alarm information, resulting in the detector's detection distance becomes shorter, no work, leakage / false positives and so on. Then Reske's Agility alarm system has environmental background noise, wireless detector signal strength, wireless detector power state detection function, which can visually display the background noise size and detector signal in digital form on the system operating keyboard. The strength of the weak and the detector's electrical energy storage will make it very convenient for engineers and users to choose the most suitable installation solution, and can replace the battery in time for the detector, so that the alarm system is always in good working condition, not just a display.
Another example is Honeywell's 58×× wireless protocol designed for wireless RF 315MHz and 433MHz, and GWP wireless protocol based on FM spread spectrum technology, which can greatly improve the security and bandwidth of signal transmission. The company will have its own agreement.
Adjustable 12V DC 500W 6/17CH Rack Mounted Integrated Power Supply 1U
This product is based on the standard 19-inch cabinet assembly, meticulous design and manufacture, adopting modular design, input voltage 90V AC--246V AC, can output 5V DC/12V DC/ 24V DC / 48V DC, A total of 16 channels are divided into 4 groups of output, digital display, Each set of voltage can be adjusted, total power 600W, with lightning protection, over-voltage protection , over-current protection , overload protection , over-temperature protection and indicator acousto-optic and alarm function, power outages can be self-locking.
Features:
Use of efficient, environmental protection switching power supply circuit frame
Modular 1U standard 19" rack mount chassis
Small ripple & noise -- video output signal more stable, clearly images
Splitter output -- by-pass failure to protect other equipment to work
Power protection -- Output over-voltage protection, over-current protection, short circuit protection
Application:
It widely used in banks, government units, buildings, office buildings, garden community, square, Factory, prison, road traffic, gas station, ship and other machine rooms, can dock intelligent APPDU system, embedded in the back-end security system management platform, is an ideal intelligent security integrated power supply and Management System.
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Power Supply 12Vdc ,Power Supply 12Vdc 5A,Power Supply 12Vdc 10A,Power Supply 12Vdc 2A
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