Homemade Resistors

Save

Electrical resistors are passive electrical components that limit current flow in an electrical circuit. Resistors can be constructed from different materials. Some of the most common materials used are metal and carbon. Carbon-based resistors are preferable to metal-based resistors where inductive interference is an issue. For many analog electric and electronic circuits, metal-based resistors (such as the wirewound resistor) can be used with no ill effects.

How a Wirewound Resistor Works

  • Electrical current flow is explained by a physical relationship discovered by Georg Simon Ohm, a nineteenth-century German physicist. That explanation is known as “Ohm’s Law.”

    Ohm’s Law explains that the voltage difference in an electrical circuit is the product of the electrical current value (in Amperes) multiplied by the circuit resistance value (in Ohms). Explained another way: an electrical circuit that has a difference of 2 volts, with 1 Ampere of current flowing through it, has a resistance of 2 Ohms.

    All electrically conductive materials are somewhat resistive, too. Because of this, even a good electrical conductor, such as metal wire, can be used as a resistor. Resistance can be adjusted by limiting how thick the wire is, and by increasing or decreasing the conductive path through the wire. Resistance can also be controlled by wire material. Some metals, such as gold, silver, and copper, are excellent electrical conductors and have a lower resistance value. Other metals, such as iron, tin, or platinum, do not conduct electrical current very well because of their higher resistance values.

Creating a Wirewound Resistor

  • To create a wirewound resistor, one piece of wire would have to serve as the path for the electrical current to flow from one end of the resistor to the other. To create a resistor with a small resistance (or Ohm) value, use a thicker, shorter wire as the path between the two electrical leads. To create a resistor with a larger Ohm value, use a thinner, longer wire.

    As the name would suggest, a wirewound resistor is typically wrapped in some way around an electrically insulated material (such as plastic or ceramic). To lengthen the conductive path and raise the Ohm value, wrap a longer wire more times around the insulator. A more direct path will lower the Ohm value and allow more current through.

    Another factor in creating a wirewound resistor is what type of wire is used. Steel wire is not as good a conductor as copper wire; therefore, steel wire may be used when a larger resistance value is needed.

References

  • Photo Credit Hemera Technologies/AbleStock.com/Getty Images
Promoted By Zergnet

Comments

Resources

You May Also Like

  • Types of Resistors

    Different materials conduct electrical current with differing facility. For example, increasing the mix of carbon in a ceramic resistor reduces its resistance....

  • How to Wire a Variable Resistor

    A potentiometer, or "pot" for short, is also known as a variable resistor. Variable resistors are used to dynamically change the resistance...

  • How to Wire Resistors in a Series & in Parallel

    Resistors are electronic components used to regulate the flow of voltage through specific parts of circuit boards. The more resistance the circuit...

  • Learn About Resistors for Homemade Synthesizers

    Learn about resistors for a homemade synthesizer in this free instrument-building video series that will show you how to create the perfect...

Related Searches

Check It Out

How to Build and Grow a Salad Garden On Your Balcony

M
Is DIY in your DNA? Become part of our maker community.
Submit Your Work!