OPEN CIRCUIT: CHARACTERISTICS AND HOW IT WORKS - PHYSICAL - 2025

An open circuit is an electrical circuit through which the intensity of the electric current does not flow, due to the interruption of the circulation path of the same. As its name suggests, it is an electrical assembly that is not closed. This implies that electrical energy cannot be transported due to the absence of a conduction medium.

Consequently, the circuit will not do any work, since the energy receivers will not have access to it. If there is an unincorporated section, either due to the deterioration or absence of any of the conductors or components of the circuit, this will be enough so that the current does not flow through it.

characteristics

Open circuits are ready-made assemblies; that is, everything is ready for its operation, except for the final connection of one (or several) of the sections, which prevents the flow of current. The main characteristics of open electrical circuits are detailed below:

Current does not flow through the circuit

A basic premise of open circuits is that electrical current does not flow through the circuit. This is due to the interruption of the conduction loop. In short, it is certain that the circulating current through the circuit will be zero.

Given the nature of electrical energy, it does not flow to a point unless there is a receiving element that demands that energy.

The demand for electrical energy is instantaneous, it cannot be stored or postponed; therefore, it occurs in real time and is evidenced when the demanding teams are connected performing a job.

If there is no physical connection that routes the flow of electrical energy from the power source to the receiving entity, it will definitely not circulate through the circuit.

The resistance between the unconnected points is infinite

By definition, in open circuits there are two terminals that are not solidly connected.

Thus, the passage of electric current through the circuit is interrupted, since the resistance that exists between the physically separated points has a very high value, which theoretically tends to be infinite.

This represents that the dielectric breakdown of the air is very high, so much that it prevents the circulation of the current through it. Except for exceptional cases - such as electrical lightning - it is assumed that air is not a conductor of electricity.

In view of this, the resistance offered to the system is very high and prevents the flow of current through it.

There is an open circuit voltage

In the opening area of ​​the circuit there is a difference in electrical potential between the terminals that are not physically connected. That is, there is an open circuit voltage.

This is because the circuit has a power source that is providing an output voltage to the system, even though current is not flowing through the circuit.

As the current does not circulate, there are no energy consumption or voltage drops in any of the circuit's receivers. Hence, the open circuit voltage is understood to be, in essence, the source voltage of the circuit.

This voltage is real, and in the event that the circuit is closed -either by the operation of a switch or the connection of another element-, the current will flow through it immediately.

How does it work?

It is an essential requirement for the circulation of electric current that there is a closed path through which it can flow. This basically involves three conditions:

- The first element of the system must be a power generating source.

- At the other end of the circuit there must be one or more energy receiving elements.

- Both (source and receiver) must be physically connected by an electrical conductor.

In the case of open circuits, this premise is not fulfilled; consequently, the electrons do not find a continuous path to circulate and, therefore, the current does not flow through the circuit.

An open circuit is considered as such as long as there is a discontinuous section to its credit. This does not depend on the nature of the discontinuity.

For example: it does not matter if it is a manual disconnection, if the conductor melted in one of its parts or if perhaps one of the receiving components is faulty. The outcome is the same: the circulation path has been interrupted and the current does not flow through the circuit.

How to do it?

To verify the nature of an open circuit, simply perform a simple setup in which a section is deliberately left without a physical connection.

Thus, the electrons will not find a return path to the energy source, and ultimately the electric current will not circulate through the circuit.

Here are the instructions to simulate an open circuit quickly and easily:

1- Select the mounting base. For this you can use a wooden board, so that the circuit is stable and the assembly is isolated.

2- Place the voltage source. You can use a standard 9-volt battery. It is important to properly fix the stack on the base.

3- Hold two bulb holders on the base of the circuit and install the corresponding bulbs.

4- Make the connection of the negative pole of the battery and the first bulb holder. Then connect the remaining terminal of the first bulb holder with the second receiver.

5- Don't close the circuit; that is, do not connect the remaining terminal of the second bulb holder with the positive pole of the battery.

6- If you have a voltmeter, measure the voltage between the open points.

You can also simulate the open circuit by connecting a switch to the positive pole of the battery, and opening and closing the circuit by activating the device as many times as you consider appropriate.

Examples

The most palpable example of an open circuit occurs in the residential environment. It is common to find electrical outlets in homes, which are, in essence, open circuits.

When an appliance is plugged into the outlet, the circuit is being closed, as a load that demands energy is being added to the system.

Thus, the current will find a circulation path and the receiving element will automatically energize.

However, when no item is connected to the outlet, it operates as an open circuit, with an associated open circuit voltage.

References

1. Open circuit and short circuit (2015). Recovered from: snaiderrodriguezacostaitec3.blogspot.com
2. Circuits - Open and Closed - Background (nd). International Space Station (ISS). Recovered from: 198.185.178.104/iss/
3. Difference between open and closed circuit (sf). © Differences.cc. Recovered from: differences.cc
4. Open circuit, closed circuit (sf). Energy Dictionary. Recovered from: energyvortex.com
5. What is Open Circuit Voltage? (sf). Recovered from: learningaboutelectronics.com
6. Wikipedia, The Free Encyclopedia (2018). Open circuit. Recovered from: es.wikipedia.org