China cell phone jammer will have the normal dissipation as the working time accumulates

38 electromagnetic shielding and application of technical analysis approach within a safe distance from overhead lines alarm signal [3]. Another component of the alarm device is receiving the wireless signal receiver, in response to sound and light alarm. Transmitter and receiver wireless transmitter receiver module PT2262 PT2272 chip, anti-jamming performance, high reliability and is widely used for a variety of short-range radio path; coded transmitter is based on the PT2262 chip encoding, with 315MHz of transmitter module, and reasonable solution to a safety device channel aliasing problems. china cell phone jammer will have the normal dissipation as the working time accumulates. Figure 2 shows the wireless alarm transmitter block diagram, overhead transmission lines generated electric field changes, the sensor detects the electric signal and converted to the corresponding change in output voltage to the amplifier. Amplified voltage signal is filtered through the filter and rectifier rectification process. After treatment by the starter according to the preset voltage and threshold voltage comparison results decide whether to activate the wireless transmitter. Third, the shielding material of choice in theory should be reflective of the high absorption of low electromagnetic shielding material is the ideal choice. Whether it is the general installation of     cell phone jammer to get the general shielding effect or the scientific and intelligent centralized controlling shielding. However, to increase the absorption loss, you must use magnetic permeability material or by superposition of layers of materials and other methods. R is the relative conductivity of tin 0.151, relative permeability 2 wireless alarm transmitter block diagram of the encoding and decoding chip chip PT 2262 PT2272 1 of 8 feet to the address set foot, there is vacant, then the positive power supply and grounded three states, namely, the address code is not repeated a total of 6561 kinds of 38. Only when the transmitter and the receiver PT2262 PT2272 of eight identical code to match the address used. Paired with PT2262 and PT2272 corresponding data input and output pins D0 ~ D5, when the address code corresponding to the data output pin when the PT2272 and PT2262 will output the corresponding data input pin of the same logic level. In the design process, the wireless transmitter module of the transmitter front-end circuit interference, affecting its normal work, must take effective shielding measures. Be well prepared for site investigation, inspection and testing of agent or manufacturer of the future     cell phone jammer    system construction project. Emission level for the purpose of a shield to prevent interference to the harmful effects within the system, and second, to prevent transmission circuit itself can not work properly. From the interference source nature, the source of interference to meet the low-voltage, high current, the loop antenna transmitter module generated interference, that is the source of interference near the main magnetic field. Because the system uses 315MHz frequency wireless transmission method, the frequency above 100kHz high frequency magnetic field shielding is the use of electromagnetic induction shielding shell surface in the vortex generated by the anti-magnetic field to achieve their goals. Figure 3 is a good conductor shield made of shell on the shield an electronic circuit equivalent circuit [4]. Which, L is the inductance of the electronic circuit, M is the electronic circuit mutual inductance and shielding shell, Ls is the inductance shielding shell, I is the current electronic circuit, Rs is the resistance shielding shell. It is the comparison of merit and demerit of     cell phone jammer    and the intelligent management system.To be formed on the shielding shell is equivalent eddy current. At low frequencies? Reduced to the equivalent eddy current, Low Is small, poor shielding.