CLOSED CIRCUIT: CHARACTERISTICS AND HOW TO DO IT - PHYSICAL - 2025

A closed circuit is an electrical configuration that has an energy source coupled with one or more receiver components, joined by a conductive material that allows the output and a return of the current. The circulation of current through the circuit makes it possible to supply the energy demand of the interconnected elements.

Therefore, it allows the completion of a job, from a physical point of view. It is also known as a closed circuit any installation that is under the mesh configuration, in which all its devices are linked to each other. For example: closed circuit television.

In short, a circuit is closed when the intensity of electric current flows from the primary energy source to the target receiver of the circuit.

characteristics

The primary objective of a closed electrical circuit is to transmit electrical energy through itself, in order to supply a specific demand. Broadly speaking, electrical circuits are characterized by the following aspects:

Current flows through the circuit

This is the main distinction of a closed circuit, since the connection of all its components is precisely what allows the electric current to flow through itself.

For a circuit to fulfill its function, electrons must find a continuous path through which to circulate freely. For this, the circuit must be closed.

If by some circumstance the continuity of this path is corrupted, the circuit is automatically opened and, consequently, the current stops its course.

They have a generating source, conductors, nodes and receiver components

The circuit can be large or small, depending on the function for which it was designed, as well as have as many components as necessary to fulfill that function.

However, there are some elements that are basic for a closed circuit to be considered as such. These are:

The generating source

It is responsible for supplying electrical energy to the system.

Electrical conductors

They are the means of connection between the generating source and the rest of the receivers. Copper cables are usually used for this purpose.

Nodes

They are common connection points between two or more components. A node can be understood as a point of bifurcation of the current, towards two or more branches of the circuit.

Receiver components

They are all those elements connected in the circuit. This includes: resistors, capacitors, inductors, transistors, and other electronic components.

Thus, the conventional cycle through a closed circuit consists of the following:

- The electric current starts from the positive pole of the power source.

- Current flows through the conductor (s).

- The current passes through the circuit components (power consumption).

- The stream forks at each node. The proportion of the current distribution will depend on the resistance of each branch.

- The current returns to the power source through the negative pole.

In this sequence, the circulation loop closes and the circuit fulfills its design function, with which each energy demand is supplied by the flow of current intensity.

The circuit configuration is free

A circuit, as long as it is closed, can have the configuration that is necessary. This implies that closed circuits can have series, parallel or mixed arrangements, depending on the interest of the application.

The type of current (DC / AC) is indistinct

Closed electrical circuits occur in any type of current, either direct current (DC) or alternating current (AC, for its acronym in English).

The type of signal will depend on the type of application. However, the principle of the closed circuit will be the same, regardless of whether the feeder emits continuous or alternating signals.

How does it work?

In a closed circuit, electrons travel from the beginning of the circuit at the positive pole of the source (current output), to their denouement at the negative pole of the source (current arrival).

That is, the electrons pass through the entire configuration, in a circulation loop that encompasses the entire circuit. Everything starts with the energy source, which induces a difference in electrical potential (voltage) between its terminals.

This difference in voltage causes the electrons to move from the negative pole to the positive pole of the source. The electrons then circulate through the rest of the connections in the circuit.

In turn, the presence of receptors in the closed circuit implies voltage drops on each component, and the performance of some work performed by one or more of the interconnected receptors.

However, it may be the case that a circuit is closed and does not perform any effective work. For example: the connection of a mesh whose energy source is a battery without charge.

In that case, the circuit is still closed, but current does not flow through it due to the failure of the power source.

How to do it?

The connection of a closed circuit can be verified by connecting a battery to a pair of bulbs, and verifying that they turn on and off as the circuit is connected and disconnected.

An elementary example of a series circuit is presented below, to demonstrate the theoretical notions previously indicated:

1- Select a wooden board and place it on a stable surface, so that this is the base of the circuit.

2- Place the voltage source. For this you can use a conventional 9-volt battery. It is important to fasten the battery to the base, with an insulating adhesive tape.

3- Locate the circuit breaker on the positive pole of the source.

4- Place two bulb holders on the base of the circuit and place the bulbs where they correspond.

5- Cut the circuit conductors to size.

6- Using the leads, physically connect the battery to the switch and to the bulb holders.

7- Finally, actuate the switch to close the circuit and verify its operation.

Examples

Electric circuits are part of our daily lives and are present in all electrical appliances and portable electronic devices, such as cell phones, tablets, calculators, etc.

When we activate a light switch we are closing the circuit that was open. This is why the bulbs or lamps connected to said switch turn on, and the desired effect is generated.

References

1. Circuits - Open and Closed - Background (nd). International Space Station (ISS). Recovered from: 198.185.178.104/iss/
2. Definition of Closed Circuit (sf). Dictionary Definition ABC. San Salvador, El Salvador. Recovered from: definicionabc.com
3. Definition of Electric Circuit (sf). Dictionary Definition ABC. San Salvador, El Salvador. Recovered from: definicionabc.com
4. Difference between open and closed circuit (sf). © Differences.cc. Recovered from: differences.cc
5. Gardey, A. and Pérez, J. (2011). Definition of Closed Circuit. Recovered from: definicion.de
6. Open circuit, closed circuit (sf). Energy Dictionary. Recovered from: energyvortex.com