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DIY High Current Inductors

An inductor is an electrical device that resists changes in current. It generates a magnetic field. It is used in filters, voltage regulators and many modern electronic devices. Inductors are often made with high-gauge wire, which is very thin, in order to make them as small as possible. However, the thinner the wire, the less current it can safely handle before overheating and posing a fire hazard. High current inductors need to be made a little differently.

Things You'll Need

Iron or steel bar
Low gauge copper wire
Ruler
Electrical tape
Wire strippers or emery board

Instructions

- 1
  Select a wire gauge with a maximum current rating above the maximum current to which your inductor will be exposed. The electronics industry usually refers to currents of 10 amps or above as high current. This means that you will need a gauge of 11 or lower.
- 2
  Measure the length of the metal bar. Measure the width and thickness, if it is square, and multiply them to get the cross-sectional area. If the bar is round, divide its width by 2, square the result, and multiply the result of that by 3.14 to get the area. Make all of your measurements in meters.
- 3
  Multiply the inductance you need your inductor to be, measured in Henries, by the length of the iron or steel bar. Divide the result by the cross-sectional area of the bar. Divide this result by the magnetic permeability of which the metal the bar is made. For steel, this value is around 50. For iron it is around 150. Take the square root of the result. This final result is the number of loops of wire of which your inductor needs to be made.
- 4
  Tape one end of the wire to one end of the bar, using the electrical tape. Leave a few inches of the wire sticking out past the tape. Wind as many loops around the bar as necessary for the inductance you need, per your calculations. Wind always from one end to the other and do not move the wire back and forth. Once you have wound the requisite number of loops, tape the free end of the wire to the other end of the bar. Cut away the excess, leaving a few inches sticking out past the end of the tape.
- 5
  Remove 1 inch of insulation from both ends of the coil wire. Use the wire strippers if the insulation is rubber or plastic, use an emery board if it is enamel insulation.

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