Basic Electronics Tutorial
Learning basic electronics requires an understanding of the vocabulary of electricity and the components used to control the electricity. Charge, an invisible force that can seem confusing at first, works quite similarly to other forces of flow that you may already understand. Perform basic electronics projects only with low-voltage equipment such as batteries, and always with an attentive adult handy.
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Understand Charge
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"Charge" refers to the physical forcepresent when current flows. Like gravity, charge itself is generally invisible, but you can observe and measure effects of its force. Measure charge in units called coulombs, abbreviated using a capital C.
Two types of charge exist: positive and negative. Though you cannot destroy charges, you can neutralize them with an opposite charge. Add a negative charge to a positively charged object to cause the object to become less positively charged; add an equal negative charge to a positively charged object to neutralize the charge. Though the object has become neutralized, it will no longer have a neutral charge if you separate the charges. Observe what happens when charges separate by rubbing an inflated balloon against your head; the charged balloon will cause your hair to stand on end. If the balloon has enough of a charge, it may stick to the wall.
Understand Voltage, Resistance and Current
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Current flows between two points over a conductive material such as metal wire. Current measures how much charge flows between the two points in a given time period; measure it in amperes, called amps for short.
A balloon with an electric charge sticks to the wall and attracts your hair because objects with opposite charges tend to attract each other. Once you have rubbed it to separate the charges, the balloon has an opposite charge to your hair and the wall. Like with magnets, similarly charged objects repel each other. The measured force of their attracting or repelling each other is called voltage, measured in volts. Voltage can be positive or negative depending on whether the measured objects attract or repel each other.
When defining the terms of measuring electric charge, think of the properties of current in relation to the properties of water. Like the water pressure in a water tank, voltage represents a measurement of the potential current force, while current represents the amount of water entering or leaving the tank at a given time.
A material's resistance affects how much electricity can flow from a source of charge. The resistance determines how a metal's ability to conduct electricity. Each type of metal has a different level of resistance that affects the power of the current. Measure resistance in ohms, abbreviated by the capitalized form of the Greek letter omega. High resistance in a metal works works similarly to a hose narrow enough to restrict the flow of water.
The Tools of Electronics
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The elements of a circuit include switches, resistors, capacitors and inductors. Use each element to control the flow of electric current in a circuit.
Switches turn the flow of current to a circuit on and off. You use switches in your home every day to turn lights and electronics on and off.
Resistors apply additional resistance to the system, stifling the flow that would usually pass over a segment of wire. A resistor plays an important role in a system because it can keep from overloading or overheating a piece of electronic equipment.
A capacitor stores a small amount of charge, like a very small battery. As charge builds up in the capacitor, it repels further charge, slowing the flow of electricity.
An inductor also controls the flow of electricity. An inductor is a coil of wire that, as current flows along it, builds up a magnetic force that causes the electricity to flow more slowly through the inductor.
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