Basic Electrical and Electronic Circuits

The first thing a beginner needs to know to understand a system of electrical circuits and electronic circuits is the understanding of basic electrical theory including electron and basic unit of electrical measurement such as the value of current, the value of voltage, and the value electrical power; the introduction of codes and electric and electronic symbols; understanding of basic electric and electronic formulas; understanding of basic electrical circuits and electronics; and ways of working components.

In principle, the basic electrical circuit consists of three parts:

1. Voltage source: Voltage source (Power Supply) can be either voltage AC (Alternate Current) 220-240 VAC from the power company or a DC voltage (Direct Current) like an Accumulator (Battery Cell)
2. Conductor: Conductor can be a cooper wire, cable, or other objects that are conductive.
3. Load:  Load can be either electric or electronic devices such as televisions, refrigerators, washing machines, computers, electric motors, radios, lamps, LEDs, etc.

The third part of the electrical circuit can be connected or disconnected by a switch. When the switch is closed, electric current will flow from the source voltage through the load so that the load will work, and will be disconnected when the switch is open (disconnect) to turn off the load.

If the resistance of the conductor ignored or considered to be zero (0 Ohm). The greater voltage source, the greater current flowing to the load. The larger the load resistance, the smaller current flowing in the electrical circuit. In this condition shall apply Ohm's Law.

Ohm's law is a statement that the electrical current flowing through a conductor is always proportional to the applied potential difference to it. A conductive object will be in accordance with Ohm's law if the resistance value does not depend on the value and polarity of the potential difference. Although this statement does not necessarily apply to all types of conductors, but the term "law" still used by historical reasons.

Mathematically Ohm's law written by the equation:

"I" is electric current flowing in a conductor in Amperes (A), "V" is the voltage present at both ends of the conductor in Volts (V), and "R" is the resistance contained in a conductor in Ohm . This law was initiated by George Simon Ohm, a physicist from Germany in 1825 and published in a paper titled The Galvanic Circuit Investigated Mathematically in 1827. (Wikipedia)