The core wire of the adapter of cell phone jammer has no exposure

Does the    cell phone jammer     need a preheat action before starting?
Low-frequency induced current is small, the shielding effect is poor; should ensure that all parts of the shell shield electrically continuous with the good, the induced current flowing in the shell in order to generate the induced electromagnetic field is large enough to offset the external electromagnetic field, otherwise it will affect the shielding effect . Loop 1 and Loop 2 flux between will not connect, so you can complete the shield. But, in fact, rarely used anti-harassment measures into the approach to magnetic shielding. This is because the appropriate ribbon tape is more expensive high-performance reasons. Truly effective and practical way is to avoid as much as possible the composition loops.The metalwork of the adapter of    cell phone jammer     has no oxidization, fungus, and stain. Shielding problems discussed above, it is important to distinguish what is due to electrical or harassment originated in the current situation must be determined in accordance with different electrostatic shielding or electromagnetic shielding. 2.3 low-frequency magnetic shielding for the magnetic field near the low frequency disturbance source (AC or DC power cord, power transformers, motors, relays, etc.), in order to protect sensitive magnetic equipment for the TF often work, the magnetic bypass is another kind of very effective shielding method, shown in Figure 4 where the magnetic field to provide a magnetoresistive ~ E4-, the channel will be bound by the magnetic field lines in this low reluctance path, so that the magnetic field sensitive devices from harassment. Can draw the following conclusions: a).The AC pin and DC plug of the adapter of    cell phone jammer     have no looseness. Low frequency, high magnetic permeability material above the tunnel shielding effectiveness of high conductivity material, but when the frequency is high, the high conductivity material may be higher than the magnetic shielding effectiveness of high permeability material. When high-frequency conductive material has a high shielding effectiveness, the reason is: the frequency increases, lower permeability, higher acoustic impedance, reflection loss increases; therefore, increase the shielding effectiveness of the method is: high permeability surface coating of high conductivity material; b). Low-frequency magnetic field shielding using high permeability magnetic alloy composition to short-circuit magnetic field lines; c). Magnetic shielding performance and the material thickness, permeability is proportional to the size and inversely proportional to shield other; d). The whisker of the adapter of      cell phone jammer has no burning, scoring, damaging and staining.Magnetic field is strong, to use the multi-layer shielded to prevent magnetic saturation; e). Machining of high permeability will reduce the shielding effectiveness of materials, heat treatment after resume; f). High permeability material permeability and frequency, is generally used only below 1 kHz; g). High permeability material plus a two special requirements, according to the manufacturer's specifications for processing, it is best to use the factory processed products.
Knowledge EMI shielding method of electromagnetic interference electromagnetic compatibility (EMC) refers to "a device, equipment or system performance, it can make it work in their own environment and this environment without any other equipment generating strong electromagnetic interference (IEEE C63.121987). "transceiver for wireless devices, the use of non-continuous spectrum can be part of the EMC performance, but many of the examples also show that EMC is not always able to do.
For example, in notebook computers and testing devices, printers and desktop computers as well as between mobile phones and medical equipment and so has the high-frequency interference, such interference we called electromagnetic interference (EMI).The core wire of the adapter of cell phone jammer has no exposure.