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How to Make a Resistor Wire

Resistors help control the flow of current in circuits. The most commonly used ones are formed from carbon, but some are made from wire. This is because a wire is not an ideal conductor, so it has properties that allow it to resist the flow of current. The size of this resistance is based on composition, length and gauge -- gauge means diameter size. To make a resistor wire, select a wire based on its properties, attach jumper wires to it and then measure its resistance. The wire chosen should have a high gauge, since thin long wires have the most resistance.

Things You'll Need

Solid wire
Wire cutter
Plastic or cardboard tubular holder
Needle nose pliers
Soldering iron
Solder
Shrink tubing
Heat gun
Digital multimeter
Battery
Resistor
Jumper wire

Instructions

- 1
  Check the gauge size against the voltage and amps that will be drawn on the circuit. This information may be found on a chart. For example, a 22-gauge copper wire that is 10 feet long can draw 5 amps at 12 volts.
- 2
  Find the resistance per 1,000 feet. This information may also be found from a table. A 22-gauge aluminum wire has 26.5 ohms of resistance per 1,000 feet, while a 22-gauge copper wire has 16.5 ohms of resistance per 1,000 feet.
- 3
  Calculate the amount of wire needed to create the desired resistance. Practice with the calculation for a 0.5-ohm resistor made from 30-gauge aluminum wire. At room temperature, aluminum̵7;s resistance is 169 ohms per 1,000 feet or 0.169 ohms per foot. This means that 3 feet is needed because 3 x 0.169 = 0.507 ohms.
- 4
  Increase the amount of wire by three times or more. In the aluminum example, the amount should be at least 9 feet. If the wire is to be wound in a circle, add 2 to 5 extra inches to function as leads or lead holders.
- 5
  Trim the wire to its proper length using wire cutters or needle nose pliers.
- 6
  Place shrink tubing over the wire and melt it into place with the heat gun. The shrink tubing is unnecessary if the wire already has insulation. If the resistor is to be a wire wound type, wrap the wire around a plastic or cardboard tubular holder before applying the shrink tubing.
- 7
  Solder jumper wires to both ends of the homemade resistor, if necessary. Test the component by placing it into a circuit formed from a battery and an ordinary resistor. Measure the component̵7;s resistance with a digital multimeter.

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