Explore a importância da resistência em circuitos eletrônicos

Explore the importance of resistance in electronic circuits

June 22, 2024 Luciano Bertene

the role of a decoupling coil and a resistor in a pdn-67998

This article examines resistors in electronic circuits and explains their main functions and properties. We will discuss how resistors affect circuit behavior, regulate current flow, control voltage levels, and provide necessary protection to other components. Additionally, we will explore different types of resistors and their applications, highlighting their different functions in circuit design.

Definition of resistance

A resistor provides resistance to the flow of electrical current. Resistance is the strength of resistance to the flow of current in a resistor. More resistance means more resistance to electrical phenomenon. The unit of resistance is ohms and is represented as Ω. If one V of electrical potential is applied to a resistor while one ampere of current flows through it, the resistance of the resistor is called 1Ω; The resistor is one of the most important passive components in electrical and electronic engineering.

Resistors are crucial for circuits and temperature stability

In many circuits, the resistor requires a minimum amount of time to introduce resistance and thus limit the current flowing through it. A resistor is a part of a circuit that does the same thing. The series-connected resistor limits the electrical current flowing through the light-emitting diode (LED). Furthermore, resistors perform several alternative functions in electrical and electronic applications.

An essential requirement for a resistor is that its resistance value does not fluctuate with large temperature fluctuations. This means that the resistance fluctuation should be as small as possible when there are large temperature fluctuations. In other words, the temperature constant of the resistor must be minimum for the materials from which the resistor is made.

Nominal voltage of the resistor

The nominal voltage of a resistor is defined as the continuous voltage that can be applied across a resistor while maintaining power dissipation within allowable limits. In fact, the voltage rating of a resistor is related to the power rating. As we know, the nominal power of the resistor is given as follows:

Where V is the operating voltage across the resistor and R is the resistance value of the resistor in ohms.

From the above equation, it is clear that to limit PV for a given resistance, it is necessary to limit with the resistance value R. This V is the nominal voltage of the resistor with the nominal power P Watt and the resistance value R in Ω.

Resistor rated power

As soon as current flows through a resistor, a I ² Loss R. Therefore, according to Joule's law of heating, the resistance must show a large increase in temperature. A resistor must work within a temperature limit. Therefore, high temperatures should not cause any harm. The rated power of a resistor is defined as the maximum power that a resistor can dissipate in the form of heat to maintain the temperature within the maximum allowable limit. The amount of power a resistor provides depends on the material, sizes, voltage rating, the resistor's maximum temperature limit, and the ambient temperature.

Resistance voltage coefficient

The resistance of a resistor can sometimes change with the applied voltage. This change is expressed as a percentage of resistance at 10% of the nominal voltage. Therefore, the voltage resistance coefficient is given by

Where R ₁ is the resistance at nominal voltage V ₁ and R ₂ is the resistance at 10% of the nominal voltage V ₂ .

The role of resistors in circuit behavior and protection

Effects on circuit behavior

Resistors have a significant influence on the behavior of electronic circuits. Its presence alters the flow of electrical current and affects other parameters of the circuit. An important aspect is resistance, which determines the resistance to current flow. By introducing resistors into a circuit, we can control the amount of current and influence the overall behavior of the circuit.

Current flow regulation

Resistors are often used to regulate current flow in electronic circuits. By connecting a resistor in series with a load, the flow of current through the package can be controlled. This is achieved by Ohm's law, which states that the current flowing through a resistor is directly proportional to the voltage across it and inversely proportional to its resistance. By adjusting the resistance value, we can limit the current to a desired level, thus avoiding damage to the circuit and its components.

Controlling voltage levels

Resistors are also crucial for maintaining voltage levels in a circuit. We can divide the input voltage into desired proportions using voltage dividers which consist of resistors connected in series. This technique is often used in a variety of applications, such as level shifting, biasing transistor circuits, or setting reference voltages. By carefully selecting the resistance values, we can obtain precise voltage regulation and ensure the proper functioning of the circuit.

Provide the necessary protection

Resistors play an important role in protecting other components in electronic circuits. For example, they are often used in series with light-emitting diodes (LEDs) to limit the current flowing through them and prevent excessive current that could damage the LED. Similarly, resistors are used in series with sensitive components such as integrated circuits (ICs) to protect them against voltage spikes and excessive current during voltage spikes or transient events. Acting as current limiters and voltage stabilizers, resistors protect the integrity and longevity of the circuit.

Conclusion

By strategically integrating resistors into circuit designs, engineers and designers can adjust current levels, regulate voltage relationships, and protect sensitive components from potential damage. Precise selection of resistance values allows fine-tuning of circuit parameters and ensures efficient and reliable operation.

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