Choosing the Right Resistor for Your Project
Electronic resistors are one of the major electronic components of all the devices that we use today. This is because of this electronic part’s wide range of applications. Resistors are everywhere in the electronic world, from microwave ovens to speakers to electric motors, stoves, heaters, and even LEDs.
But resistors come in different types, and that is where things get a little complicated. People usually do not know which resistor is right for their project. This often leads to confusion and results in selecting a resistor that is not best suited for a particular project.
We will discuss different factors that must be kept in mind while choosing the resistor for your project. But before we dive into the selection factors, let us see what exactly a resistor is and how this electronic component has become so important in our lives. Let’s begin!
What are Resistors?
As their name suggests, resistors are electrical components that resist the flow of electric current within circuits. Since they control the flow of electricity, they are made of a material that is difficult for the electric charges to pass through. This is commonly referred to as the resistance. Copper and carbon are the most commonly used materials, which resistors are usually made of.
Importance of Resistors
Resistors are important in circuits for the following reasons.
- Protection Against Voltage Spikes – if a resistor is removed from a device like LED lights, there is a high chance that such devices will not be able to resist (quite literally) sudden spikes in electric current flowing through them.
- Provision of Required Voltage – resistors ensure the provision of proper voltage to the electrical components because every component has a different voltage requirement.
Types of Resistors
Electronic resistors are not of a single type; rather, they have a number of different types depending on various factors. Following are the two major types of resistors.
1. Linear Resistors
The resistance value of linear resistors changes with the change in temperature and the applied voltage. Linear resistors are further divided into two types.
- Fixed Resistors – This type of linear resistor is the most commonly used resistor. The resistance value of the fixed resistors is fixed at their design phase. Using various resistor materials allows for this.
- Variable Resistors – In contrast to fixed resistors, the resistance value of variable resistors is adjustable. The resistance value is changed in variable resistors through mechanical movement, which can be either linear or rotary.
2. Non-linear Resistors
In non-linear resistors, the flow of electric current changes with a change in temperature or the applied voltage; however, it does not follow Ohm’s law. Non-linear resistors can also be of different sub-types.
- Thermistors – These non-linear resistors are temperature sensitive; therefore, their resistance changes with a change in the temperature value.
- Photoresistors – As their name suggests, these resistors are sensitive to light, and they change their resistance value in response to the light intensity.
- Varistors – These resistors are voltage-dependent resistors. The resistance value of varistors depends on the amount of voltage applied. As the voltage changes, the resistance of varistors also changes.
Factors To Keep in Mind While Choosing a Resistor
We now know that there are a number of types of resistors. Therefore, some important factors need to be considered to ensure that you choose the right type of resistor for your project. These factors include:
Resistance Value of a Resistor
It is important to know the resistance value of an electronic resistor before finalizing it. This is because the resistance controls the flow of current in a circuit. The resistance value of a resistor depends on the amount of current that will be allowed and the required voltage.
Power Rating of a Resistor
Another factor to consider while choosing a project’s resistor is its power rating. A resistor is bound to burn out if too much power stress is applied to it. Therefore, the power dissipation of a resistor must be found to ensure that your chosen resistor will withstand the power stress.
Tolerance of a Resistor
Tolerance is also important when selecting the appropriate resistor for your project. The tolerance of an electronic resistor is the variation that a resistor can safely withstand. Tolerance is always represented in percentages like 5%, 10%, etc. This means a 1000 ohms resistor with a tolerance of 10% will have a range between 900 ohms and 1100 ohms. It must also be remembered that for critical circuits, always go for resistors with a lower tolerance.
Temperature Coefficient of a Resistor
The temperature coefficient measures the variation in an electronic resistor’s resistance in response to the changing temperature. Different resistors have different temperature coefficient values. A smaller value of the temperature coefficient is always better because this means that the resistance of a resistor will not be greatly dependent on temperature changes.
Operating Temperature Change of a Resistor
The operating temperature of a resistor should also be considered when selecting an electronic resistor. As the name suggests, the operating temperature is the temperature at which a resistor will safely operate without burning out.
If, for example, your product will be exposed to a maximum temperature of 75 degrees Celsius, then you should choose a resistor with an operating temperature of more than 75 degrees Celsius.
Other than the aforementioned factors, a resistor’s size and mounting style are also important factors when it comes to resistor selection.
Conclusion
Electronic resistors are important components in circuits as they control the current flow through a circuit. There are a number of different types of resistors, with fixed resistors being the most common type.
Now, when it comes to buying the right resistor for a certain project, people often get confused about what factors to keep in mind while selecting a resistor for a project and where to buy resistors from.
This article gives the answer to the first question in detail. As for the second question, Partstack is the place for all such purchases because it is the fastest-growing marketplace for buying, selling, and discovering new electronic parts.