Cell phone blocker can make the cell phone unavailable for calling

Drawback is that installation requires a certain structure, and this must be considered early in the design. As the work of modern electronic equipment more frequently to deal with the increasing frequency of electromagnetic interference, so interference filters installed on the panel to become a trend. A use is very convenient, very superior performance of the device is filtered connectors. Filter connector shape and general appearance the same connector can be directly replaced. It's on each pin or hole has a low-pass filter. Low-pass filter can be simple single-capacitor circuit, it can be more complex circuits. Solve the interference on the cable of a very simple way is to set the cable on a ferrite bead, although this method is often effective, but there are a number of conditions. cell phone jammer can prevent using of cell phone from making the noise in the meeting. Many people placed high expectations on the ferrite, as long as a cable radiation encountered problems on the set of ferrite on the cable, are often disappointed. The effect of ferrite bead prediction equation is: to improve common-mode radiation = 20lg (plus common-mode magnetic loop impedance after / plus magnetic loop before the common-mode impedance) For example, if the time did not increase the ferrite common-mode loop impedance of 100Ω, after the addition of ferrite is 1000Ω, the common-mode radiation improve 20dB. Note: sometimes put ferrite, the electromagnetic radiation is not significantly improved, this is not necessarily ferrite does not work, but may be in addition to this cable, there are other sources.  cell phone jammer can make the theater and church quiet. Use a ferrite bead on the cable, pay attention to the following questions:  magnetic bead as small as the diameter of the wall as thick as long as possible magnetic bead should be installed at the cable ends from: Today, electronic intelligent building electrical protection and grounding [Zhuantie] Abstract In this paper, several power grounding system overview, filter out the power supply suitable for intelligent building grounding system, and they should take all kinds of grounding in a relatively detailed description and analysis of intelligent buildings should be taken to protect the electrical grounding method is proposed with appropriate recommendations. Key words load balancing potential reference point TN-S single-point grounding anti-static grounding uniform grounding in the design of buildings for power distribution, grounding system design plays an important role, as it relates to the power supply system reliability, safety of. cell phone blocker can make the cell phone unavailable for calling or being called.  No matter what kind of building, in the total supply includes the design of grounding system design. Moreover, with the building requirements are different, different functions of various equipment, grounding systems accordingly different. In particular, after the 1990s, the emergence of a large number of intelligent building design of the grounding system a lot of new content. Common ground in several ways, which can be suitable for intelligent buildings? Let us analyze the following types of grounding systems. System is called the three-phase four-wire system, neutral and protective earth PE combined N, known as the PEN line. Although this grounding system with high sensitivity for ground faults, line economy is simple, but is only suitable for three-phase load more balanced place. cell phone jammer can stop students from texting during the class. Intelligent building, a larger proportion of single-phase load, it is difficult to achieve three-phase load balancing, PE N-wire line with the current imbalance due to the presence of fluorescent lights, thyristor (SCR) and other equipment caused by high harmonic currents in the non-failure cases, superimposed on the neutral line N, the neutral line N voltage fluctuations, and the current is varying very unstable, resulting in an unstable neutral point grounding potential drift.