Cable Shielding

Because cables are typically the longest component of many electronic systems, they are also the most prone to radiate and most susceptible to electromagnetic interference. Proper cable shielding can make a difference of close to 80dB in some cases, so it is a topic well worth spending the time to understand. There are two basic cabling types that provide shielding: coaxial cables and twisted wires pairs. Coaxial shields provide an inherent immunity to electric field interference, and twisted pairs provide an inherent immunity to magnetic field interference.

The worst type of cabling is that of a single wire, using the ground for return. The Earth's impedance can vary greatly, and the large loop area involved makes these systems horribly noisy. The Earth return system was used for telegraph and telephone systems of the late 1800s and early 1900s, but it was soon realized that they were much too susceptible to crosstalk and interference from manmade and natural noise sources. Crosstalk may not have been a problem when there was only one telegraph or telephone cable in each town and no radio stations, but as the electronic age was ushered in, engineers switched to using two-conductor transmission lines.

Solar Panel Basics

Solar Panel Basics

Global warming is a huge problem which will significantly affect every country in the world. Many people all over the world are trying to do whatever they can to help combat the effects of global warming. One of the ways that people can fight global warming is to reduce their dependence on non-renewable energy sources like oil and petroleum based products.

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