All electronic equipment is made up of a number of component parts that work together, modifying and managing current and voltage in a variety of different ways. Here is a brief overview of the functions of each of these basic electronic components.
An integrated circuit is a special component that contains an entire electronic circuit, complete with transistors, diodes, and other elements, all photographically etched onto a tiny piece of silicon. Integrated circuits are the building blocks of modern electronic devices such as computers and cellphones.
Resistors are simple electronic components that limit the amount of current passing through a circuit. On a board, resistors are small horizontal cylinders bearing four or five colored stripes; the stripes are a code that reveals the part’s resistance in ohms. For example, the color code red-red-orange-gold is a 22,000-ohm resistor accurate to 5 percent. A board may have dozens of resistors.
Next to resistors, capacitors are probably the second most commonly used component in electronic circuits. A capacitor is a device that can temporarily store an electric charge.Capacitors come in several different varieties, the two most common being ceramic disk and electrolytic. The amount of capacitance of a given capacitor is usually measured in microfarads, abbreviated μF.
A circuit board may have one or more connectors attached to it; a cable snaps onto the connector and carries electrical signals from it to other parts of the electronic equipment. Connectors are usually plastic and have one or more metal pins or fittings that mate with the cable.
A transistor is a three-terminal device in which a voltage applied to one of the terminals (called the base) can control current that flows across the other two terminals (called the collector and the emitter). The transistor is one of the most important devices in electronics.
A diode is a device that lets current flow in only one direction. A diode has two terminals, called the anode and the cathode. Current will flow through the diode only when positive voltage is applied to the anode and negative voltage to the cathode. If these voltages are reversed, current will not flow.