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What Is Radio Frequency Induction? Part 3
Induction is everywhere. The flow of current in the 50 or 60 Hz A.C. power lines are producing magnetic fields. These magnetic fields are inducing currents into countless systems in the environment. The systems that are receiving these currents are systems that are able to conduct electricity.
Any electrical or electronic circuits are subject to this induction. Any metal structures, appliances, etc. will have currents induced in them. Any chemical system that is electrically conductive will have currents induced in them, including a simple glass of water with some salt dissolved in it. Yes, the human body has water and at least 12 different salts in it and can have currents induced into it by fields.
There are many sources of magnetic fields, because there are many types of equipment that either deliberately or inadvertently generate these fields.
Exampls of equipment that intentionally generate fields, include: cell phones, cordless telephones, walkie talkies, broadcast stations, radars, microwave ovens, wireless internet systems, Blue Tooth devices, remote controls, etc.
Examples of equipment that unintentionally generate fields include: al manner of switching power supplies from the little boxes that plug into a wall AC outlet to computer power supplies, residential, commercial and industrial control systems, including the ubiquitous motor speed controls for fans, any computer or embedded processing system (micro-controllers, micro-processors) that are found in appliances, etc.
All of these devices are producing fields, and those fields, to a greater or lesser degree are inducing currents into various systems, including our bodies. The stronger the field the more current is induced. The closer to the antenna (whether an intentional antenna or an unintentional antenna), the stronger the field and therefore the greater is the current that is induced.
In the case of someone wanting to reduce their exposure to cell phone radiation moving away from the antenna of the cell phone is a good idea.
In the next part we will begin to explore the two common approaches to ebbing the flow of RF energy in a circuit or a conductor.
NOTE: We have not treated the subject of another type of field – the Electric field. The Electric field is similar in some ways and different, very different in other ways. Suffice it to say that the discussion on fields is similar for the Electric field.
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