How to Choose the Right Resistor
When working with a printed circuit board (PCB), it is vital to incorporate one or more resistors as a means of controlling current flow and for the benefit of other applications. These include dividing voltage, generating heat, matching and loading circuits, controlling gain, powering LED lights, and fixing time constraints. For any electronics project you might partake in, it is important to understand what exactly a resistor is, how it functions, and how to choose the right design. As such, this blog will provide a brief overview of all you need to know.
Essentially, a resistor is one type of passive electrical component used for creating resistance in the flow of current through a circuit. A resistor’s value is determined by its resistance as measured in Ohms (?). Resistors can be categorized by either their construction type or their resistance material resistors, as both factors impact their functions.
When looking at construction types, resistors can be fixed or variable in their resistance levels. While fixed resistors have a fixed-resistance and tolerance regardless of any changes in external factors like temperature or light, variable resistors and physical quality resistors have changing resistances. The difference between these two is that a variable resistor requires a manual change to its modifiable resistance, while physical quality resistors can change their resistance on their own based on a variety of physical properties. Most variable resistors incorporate a dial that can be turned to increase or decrease resistance. Meanwhile, physical property resistors use changes in temperature, light levels, and even magnetic fields to adjust their resistance.
The material of the resistor you choose also makes a big impact on its function. For example, carbon composition resistors are a more outdated material design as they have a low degree of precision. Today, metal and metal oxide resistors are the most widely used, and are better for providing a stable tolerance and resistance, while also being less influenced by changes in temperature.
Once you have decided on the type of resistor that makes the most sense for your applications, it is important you understand how to operate one. One such application is to measure electrical current by monitoring voltage drop in a circuit. You may also use a resistor in tandem with an LED light to prevent it from receiving too much current and burning out. Other common applications include slowing the ventilation system in a car, and more.
Before purchasing your resistor, it is important to calculate your required resistance with Ohm’s law, so you slow your system enough without slowing it down too much. Then, it is important to calculate the amount of power your resistor will dissipate with your calculated resistance value. Lastly, you should determine the proper construction and material type needed for the resistor.
When you are ready to move forward with the procurement process, make Purchasing Efficiency your purchasing partner. As an ASAP Semiconductor owned and operated enterprise, we make quality the cornerstone of all we do. With access to an inventory of over 2 billion new, used, obsolete, and hard-to-find part types from manufacturers around the world, you can rest assured that all orders you place with us will ship to you alongside their applicable manufacturer and trace documentation. As such, we encourage you to browse our ever-expanding inventory at your leisure until you locate one or more items you desire. Then, kickoff the procurement process by submitting a completed Request for Quote form with all details relevant to your purchase. Our team of experts uses information like target prices, shipping deadlines, and desired quantities to formulate custom quotes for your comparisons in 15 minutes or less. To learn more, call or email us at any time, 24/7x365!