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Production run of GpSpeed controllers !
Production run of GpSpeed controllers !

Electrics The Basics

To understand the basics of Electrics and Electronics you need to understand the principles of electricity. This Atomall comes down to the study of a small particle called an electron. All the materials around us are made up from Atoms. An atom has a positively charged nucleus and a set of negatively charged electrons surounding it. Different materials have different numbers of electrons and different nucleouses. The electrons are attracted to the nucleous as it has opposite charge (negatively charged electrons are attracted to positively charged things). In some materials the electron is relatively losely bound to the nucleus and can be moved from atom to atom relatively freely. These materials are called conductors. In other materials it is hard to move the electrons, these materials are called insulators.

Electrics and Electronics involves moving these small particles around circuits to make them do useful things. One aspect of an electron is that it is very small and light. This allows it to be accelerated to very high speeds close to the speed of light, 299,792,458 meters per second, and moved backwards and forwards very quickly (more than 1000,000,000 times per second).

In electrics and electronics we manage and measure the flow of these electrons around circuits of conductors, resistors and semi-conductors. Unfortunately we cannot easily see electrons flowing around a circuit and thus need to use instruments to measure the flow of electrons. To provide a basic understanding of electricity and the flow of electrons an anology with the flow of water in pipes is often used. This is not a perfect anaolgy, but can be useful to aid basic understanding. There are a number of important attributes and parts used:

  • Voltage: This is a measure of the "pressure" of electrons. This is measured in Volts and we use a Volt Meter to measure it. This can be likend to the presure of water.

  • Current: This is a measure of the amount of electrons that are flowing due to the pressure of electrons (Voltage) through a material (could be a wire). This is measured in Amps and we use an Amp Meter to measure it.This can be likened to the amount of water flowing.

  • Resistance: This the the amount of resistance to electron flow a material or component has. It is measured in Ohms and we use an Ohm Meter to measure it. This can be liked to a narrow or big pipe.

  • Battery: A battery or other power source can be thought of as a pump of electrons that will pump a current of electrons around a circuit.

In order to do anything with electrons, we nee to get them moving. This can be accomplished in a few ways:

  • An electrostatic field. The Negatively charged electrons are repulsed from negatively charged things and attracted to positively charged things.
  • Magnatism: A magnetic field can be used to move electrons. This is used in generators. The reverse is also true, a moving electron can create a magnetic field. This is used in electric motors to move things.
  • A battery: This is an electro chemical pump that uses chemical reactions to move electrons between two conducting plates.

There is a useful law called "Ohm's Law" that defines a relationship between Voltage, Current and Resistance. This is defined in terms of a mathmatical equation:

Voltage = Current x Resistance