Electronic Components: Capacitors, Diodes, and Transistors

Electronic Components and Their Applications

Applications of capacitors include acting as battery charging and power circuits. The known duration of loading and unloading processes makes them essential in timing circuits.

Diodes and Their Functions

Diodes are active components that allow electric current to pass in one direction and block it in the opposite direction.

Types of Diodes

• Regular: These show the general behavior described above.
• Special: These include additional features that expand the applications of diodes.

Key Applications of Diodes

The most important application is switching, or turning on and off automatically, allowing the passage of current for positive voltages and blocking it for negative voltages. They are also used to protect circuits against discharges by diverting the flow the other way.

Transistors: Active Control Components

Transistors are three-terminal active components designed to control the current flow between two terminals through the third terminal.

Types of Bipolar Transistors

• PNP Transistor: Formed by two P-type semiconductors and one N-type; the current enters the emitter and exits the collector.
• NPN Transistor: Formed by two N-type semiconductors and one P-type; the collector current enters and exits the emitter.

Characteristics of Electronic Devices

Electronic devices process information using electrical signals. They have inputs, processing, and outputs for information. Their components may be discrete or individual:

• Passive Components (Liabilities): These are components that do not adjust the amplitude of the signals.
• Active Components (Assets): These are components that modify signals and include integrated circuits.

Resistors and Current Flow

Resistors provide resistance to electrical current flow. There are resistors whose value is fixed, meaning they have a constant resistance. Others have values that can change manually, such as potentiometers, or change based on light (LDR) or temperature (NTC or PTC).

Capacitors: Storing Electric Charge

Capacitors are passive components designed to store electric charge. They consist of two conducting plates separated by an insulating layer.

Types of Capacitors

• Fixed Capacitors: These have a fixed capacity stamped on the package along with the maximum voltage they support. They can be:
  • Electrolytic: These have a polarity that must be respected.
  • Non-polarized: Their dielectric shows that the direction of the connection is indistinct.
• Variable Capacitors: These are composed of moving plates. Moving a cursor rotates the plates so that the variation of the surface area facing the plates changes the capacitance of the capacitor.