Cell phone blocker can avoid students using the cell phone in the class

Different holes in the surface leakage will not increase, because of its radiation in a different direction, this feature can be used in the design of one side to avoid excessive radiation. In addition to pore size is much smaller than the wavelength of electromagnetic waves, as far as possible away from the hole with radiation and other methods other than reducing the leakage holes, holes increase the depth of holes can reduce the leakage, which is the principle of cut-off waveguide. Under normal circumstances, different parts of the chassis shield junction can not be completely exposed, can only touch on some points, which form a hole array. Gap is caused by degradation of the shielding effectiveness of shielded enclosures one of the main. cell phone jammer has the unique over-current and over-voltage protection Reduce the gap leakage method: ● increase the conductive contact points, reducing the width of the gap, such as using mechanical processing means (such as the contact surface with the milling machine) to increase the contact surface roughness, increase fasteners (screws, rivets) density; ● to increase the overlap between two metal plates area; ● use of electromagnetic sealing gasket, sealing gasket is a flexible magnetic conductive material. If the gap at the installation of a continuous magnetic seal on the liner, then, for the electromagnetic wave is concerned, just as in the liquid container lid after use of a rubber gasket does not occur as fluid leakage, the leakage of electromagnetic waves does not occur.  cell phone jammer has machine body made of aluminum material and good heat dissipation performance.3 through the shield conductor shield caused by failure of the treatment, another main reason is through the shield conductor. In practice, many of the shielding structure is very tight enclosure (cabinet) is due to conductor shielded box which led directly through the electromagnetic compatibility test failed, which is the lack of electromagnetic compatibility experience designers confused the typical problems. This problem is to determine the device on the test is not necessary to disconnect the connection cables, electromagnetic compatibility if the problem disappears, the cable is causing the problem factors. There are two ways to solve this problem: ● cell phone jammer can prevent some students from cheating in the exam. For the lower frequency signal transmission cable, the cable port at the use of low-pass filter, filter out unwanted high frequency cable frequency components, reducing the electromagnetic radiation generated by the cable ( most likely because of high-frequency current radiation). The same can also be induced on the cable to prevent noise transmission into the device's electrical circuits. ● For the high frequency signal transmission cable, low-pass filter can cause signal distortion, then the method can only be shielded. But pay attention to shielded cable shield to 360 ° lap, it is often difficult. Installation of the cable port has two low-pass filter mounted on the circuit board. ● This method has the advantage of economic disadvantage is the high-frequency filtering is ineffective. cell phone blocker can avoid students using the cell phone in the class.  Obviously, this drawback for this purpose, the filter is very fatal, because the purpose of the filter we use is likely to lead to filter out high frequency signal radiation, or high-frequency electromagnetic waves in the cable space on the induced current. ● Install the panel, the filter is installed directly on the metal panel on the chassis shield, such as feed-pass filter, the filter array panel, filter connectors. As installed directly on the metal panel, the filter input and output are completely isolated, well-grounded, wire port on the chassis of the interference is filtered, so filter achieved very good results.