eli5: how does a rf safestop work?
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it’s a narrow-beam EMP that is supposed to shut down car engines by jamming their electronics:
https://phys.org/news/2013-12-pulses-immobilize-cars-rf-safe-stop.html
The article is from 2013, yet we do not see it used widely. I suspect it will not work on older car with no electronics, it can be blocked by simple shielding, and also the range seems a bit limited (50 meters in article)
It’s a medium power radio frequency jammer that’s intended to disrupt automotive computer systems. This might cause a modern car to stop moving in a less dangerous way that using a police car to push them, like the pit maneuver. Of course, it doesn’t work on cars and trucks with analog engine controls, so that 66 Thunderbird is still going to blaze past your checkpoint laughing “Keep on going”.
There is a fundamental field that extends throughout the entire universe called the “electromagnetic field”. Certain kinds of disturbances in this field we defined as positive and negative charges. When charges move they create disturbances in the electromagnetic field around them. In a practical sense when electricity flows through a conductor it creates a magnetic field around the conductor, and when a conductor is exposed to a changing magnetic field it will create an electric flow within the conductor. This phenomenon is called “induction” and is crucial to understanding how many kinds of modern technology works.
For example an electric motor and an electrical generator are basically the same thing just in different directions. The motor uses electricity to make magnetic fields to turn a rotor, and the generator turns a rotor to create changing magnetic fields that create electrical current. Radio communication uses electrical current to wiggle the electromagnetic field, and an antenna is basically just a conductor so those wiggles induce a small electrical current which is detecting the transmitted signal.
The technology you reference “RF Safe-Stop” uses these concepts. The “RF” stands for “radio frequency”, and basically what they are doing is blasting out a very powerful radio transmission which is tuned to the lengths of wire in the target car’s electrical system. Just like as described above the disturbance in the electromagnetic field will induce a current in a conductor, which means they are remotely introducing current into the car’s electrical system.
Modern vehicles use computers to manage the car’s systems, and are constantly monitoring things like engine timing and diagnostic information. Putting these random unexpected signals into the electrical system will confuse the computer and make the car shut itself down, killing the engine.
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