Understanding Electricity and Electronics: DC and AC

Understanding Electricity and Electronics

Electricity

Matter is formed by atoms consisting of negatively charged particles (electrons) and positively charged particles (protons). Between these particles, there are forces of attraction or repulsion that generate a type of energy called electricity.

In a balanced atom, the number of protons is equal to the number of electrons. The forces of attraction and repulsion between these particles are balanced. When this balance is disturbed, the electrical forces become unbalanced and the electrons are driven by their electrical energy to other atoms in search of new balances.

We call this transfer of charges electrical current, and it is produced in conducting materials.

Conducting materials transmit electrical energy across their surface.

Electric circuits allow us to use electricity as light or other forms of energy (heat, sound, or movement).

Electronics

Electronics is the branch of physics that studies the control of the movement of electrons in semi-conducting materials.

The behavior of semi-conducting materials is halfway between conducting and insulating materials.

Under normal conditions, these materials do not conduct electricity (they are insulators). However, when certain factors are changed (electric fields, magnetic fields, pressure, etc.), they become conductors. The most common semi-conducting materials are silicon (Si) and germanium (Ge).

Electronic circuits are mainly used to control and distribute information. They have been very important in the progress made in computing.

Analog Electronics and Digital Electronics

We can divide electronics into two main branches: analog and digital. In this unit, we will discuss analog electronics.

• Analog electronics studies systems where the variables (current, voltage, etc.) can take on any values over time, i.e., they are continuous.
• Digital electronics studies systems where the information is encoded in discrete values (traditionally zeros and ones).

An electronic circuit can have analog and digital areas. Very often, the inputs and outputs of a digital system are analog.

Direct Current

Direct current (DC) is the current produced when electrons always move in the same direction inside an electric circuit.

These electrons move from the negative terminal of the cell in the circuit to its positive terminal.

In direct current circuits, the voltage is constant and is only a few volts. The current that flows through these circuits is also small.

Cells and batteries supply direct current. The appliances powered with DC are usually portable devices (computers, mobile telephones, battery-powered toys, personal care devices, small tools, etc.).

Alternating Current