Electromagnetic shock waves N.Tesla! EMP will destroy any unprotected electrical equipment
In this issue I want to show the effect of an electromagnetic pulse, which leads to instant damage not only to complex electronic devices, but also to any unprotected electrical equipment, including power equipment. For some reason, many are sure that UAZ or gazelle cars do not have electronics and that these cars are not afraid of any EMP. It's a delusion!
The fact is that high power EMP causes overvoltage and short circuit in the switched on electrical equipment of any unprotected device. It is included! I'll explain why next.
Let's consider the mechanism of how exactly this happens. For example, in the body of a car there is a wire in which there is a section with micro-damage to the insulation. The wire itself is laid close enough to the conductive metal surface of the body. An electromagnetic shock wave acting on a car induces an EMF in a wire with a sufficiently high voltage amplitude. High frequency vibrations and standing waves are generated in the wire. The voltage in the area with micro-damage to the insulation relative to the car body in some way can reach a critical level and lead to a breakdown between the wire and the body. By itself, a high-frequency electric arc has a negligible energy of a few mJ and only exists for a fraction of a second. Therefore, it does not pose a particular threat. But, the situation changes dramatically if the wire is energized and connected to a voltage source with low internal resistance. For example, to a battery or generator. Here events are not developing in the best way. A spark breakdown in the area with insulation damage caused by EMP forms a conductive plasma channel between the core wire and the case, which closes the wire with the case for a few microseconds. Because Since the plasma channel has a high conductivity, the short-circuit current increases like an avalanche, the arc energy increases, and the temperature of the plasma channel also increases. An arc is formed already with an energy of several J, the short-circuit current reaches tens of amperes and finally destroys the insulation of the wire. As a result, there is a short circuit in the wiring and the operation of the fuse-link. In the worst case, the wire melts and can catch fire. To clearly demonstrate this effect, I had to put together a small stand. The EMP receiver is a half-wave dipole with a spark gap in the center. The interelectrode distance is approximately 1 mm. The arms of the dipole are connected to a switching power supply with an output voltage of 24 V DC. The voltage of the pulse unit is controlled by a dial voltmeter. The switching power supply must be of an obligatory industrial design with built-in filters for suppressing impulse noise. Otherwise, the UPS will instantly fail from the effects of EMP. If you are interested in how this happens, write in the comments. I'll take a video on this topic. The voltmeter must be a pointer. Electronic, even if it does not fail, it will definitely show nothing.
Of course, it would be possible to apply a voltage of 230 V to the shoulders of the dipole through an automatic machine or a fuse-link. The experiment would be more descriptive. But the electrical wiring in my house is very old and there is no desire to arrange a stress test for it. :-)
Now I will tell you what happens when you start the EMP generator. If no voltage is applied to the shoulders of the dipole (the power supply is turned off), then a violet sparkle, barely visible to the eye, is visible in the spark gap. The camcorder does not see her. For the purity of the experiment, he covered the spark gap of the emitting unit with a towel to exclude ultraviolet illumination of the spark gap of the half-wave dipole. When the power supply is turned on, a bright white arc appears in the spark gap of the dipole. The output of the power supply goes into a short circuit and the output current overload protection built into the switching power supply is triggered. The voltage on the shoulders of the dipole drops and the arc is extinguished. Without short-circuit protection, the dipole arrester would quickly melt.
The above effect is manifested not only when the electrical equipment is exposed to EMP. A similar scenario can develop, for example, from a lightning strike.