Basic Topics for Electronics Engineering.

In this tutorial, we are going to learn about basic electronics.


Resistors are Electronic devices that are designed to restrict the flow of current and there by create a voltage drop-change within a circuit. Other devices run at various current and voltage levels; resistors are used to create the static conditions inside a circuit to enable other control ling devices to function properly. Resistors are the most common part you will find on a circuit board.

The resistor and its symbol- the component uses a color code or number to indicate its resistive value in ohms


A Capacitor component is similar to a battery; it is designed to hold energy in the form of an electrical charge. The units of the device are rated in Farads and are based on the amount of energy storage capacity. These devices are available in microelectronics size or can be the size of a TV set. Because of their ability to remain energized even with power is turned off, you must use extreme care with large size devices. It is possible to receive a fatal charge from a de energized circuit containing these devices.

Inductors and Transformers

Inductors and transformers are simply wire wrapped around a metal or air core. As current flows through a wire, it creates a magnetic field around the wire, by wrapping the wires upon themselves many times you create a dev ice with a stronger magnetic field. Magnetic energy is used inside electrical circuits and devices as controlling element. An example is a transformer used to reduce the level of AC voltage. Another use is to hold a magnetic field and then release the energy back into an electronic circuit as needed. An inductor can push or pull, this is used extensively with electric motors. Inductor/Transformers are rated in Volt-Amps or Henrys

These are the symbols used to show an inductor with two terminals and a transformer with four connections,

Fuses and switches

These are mechanical parts used to protect and control power applied to circuits or external motors or assemblies. Fused are rated by Ampere maximum limits and Voltage for maintaining physical integrity when the fuse blow. Switches have limits of voltage and current and are more versatile in their construction. With a switch, the greatest danger is a flash when the switch is opened or closed. This flash can damage the contact surfaces of the switch.


Another class of parts that make up parts of the circuit components of modern electronic devices are called Semi-conductor. Materials fall into three categories, they can be magnetically weakly bond to make good conductor, they can have strong magnetic characteristics and be an insulator, or fall exactly in the middle, being neither a good conductor nor good insulator -this material is called semi –conductive. With doping semi   -conductive materials can be having insulation or conductive properties.

All matter is made up of groups of elements called atoms, this is the building block of matter, and electrically the outside area of the atom provides a useful tool for use with electricity. The more electrically charged electrons found there the more resistance the materials has as a conductor. A low number of electrons in the outer surface provide easy use in moving current. Semi conductors are exactly in between these two extremes, not a good conductor or insulator. The material is then doped with other elements to make them good conductors or good insulators with various electrical conditions. This is useful to control electrical characteristics such as limiting the amount of current flow or reflecting a change of voltage at a higher voltage than the source voltage within designed circuits. The electrical terms for this is rectifying or amplifying.

Three common devices that are made with semiconductors, they are the Diode, the Transistor, and the Integrated circuit. Modern life would not exist without these three devices.

IC Chips – Integrated Circuit Devices

As circuits are created using discreet parts such as conductors, switches, diodes, capacitors and inductors, the need to make circuits smaller and more   powerful resulted in the integration of many components inside of a single assembly. This first stared as small circuit boards that were covered with insulation plastics, with even increasing parts needed for more complex circuits, the components were ma de so small that a circuit board contains thousands of parts could be made to fit on the back of a fly. This is an incredible feat completed in just decades of time!

It is hard to imagine that today’s integrated circuits have conductor surfaces just atoms    wide.     One integrated circuit IC chip can do fantastic work such as the job of a Color TV that would weight 100 Ibis just 20 years ago.

Each IC has a part number – Each pin of the device requires differing electrical demands to work properly. If too much energy is pulled out of a pin of pushed in – the device may simply shut off or with excessive power can be damaged. Some pink take control voltages and current, others reset the device; all chips need a power and a ground pin. IC’s are easily diagnosed with proper documentation. Start with checking reset pink, power and then input signals.

Other Devices

In addition to the general parts described   in his section, specialized components exist that do unique tasks within a circuit, include electronic switching such as with SCR’s, Triad and Data switches, or isolations of circuits with photo optical transistors or LED’s. The key to understanding any electronic component is good documentation. Manufactures can provide technical details or this information may be available from specific generic technical manuals.

The Internet is also a great source to find exact specifications or technical del ails of a component such as those shown below.

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