How to Make an Inductor

PARTS AND MATERIALS

• 26 Feet (8 Meters) of 26AWG Magnet Wire (Radio Shack catalog #278-1345 or equivalent)
• 6/32X1.5 inch screw, a M4X30mm screw, or a nail of similar diameter cut down to size, steel or iron, but not stainless
• Matching lock nut (optional)
• Transparent Tape (optional, needed if using screws)
• Super Glue
• Soldering Iron, Solder

As has been mentioned before, this is not a precision part. Inductors in general can have a large variance for many applications, and this one specifically can be off on the high side a large amount. The target here is greater than 220H.

If you are using a screw, use one layer of the transparent tape between the threads and the wire. This is to prevent the threads of the screw from cutting into the wire and shorting the coil out. If you are using a lock nut put it on the screw 1" (25mm) from the head of the screw. Starting around 1" from one end of the wire, use the glue to tack the wire on the head of the nail or screw as shown. Let the glue set.

Wind the wire neatly and tightly 1" the length of screw, again tacking it in place with super glue. (Figure45033.png above). You can use a variable speed drill to help with this, as long as you are careful. Like all power appliances, it can bite you. Hold the wire tight until the glue sets, then start winding a second layer over the first. Continue this process until all of the wire except the last 1" is used, using the glue to occasionally tack the wire down. Arrange the wire on the last layer so the second inductor lead is on the other end of the screw away from the first. Tack this down for a final time with the glue. Let dry completely.

Gently take a sharp blade and scrap the enamel off each end of the two leads. Tin the exposed copper with the soldering iron and the solder, and you now have a functional inductor that can be used in this experiment.

Here is what the one I made looked like: Figure45034.png below.

The connections shown are being used to measure the inductance, which worked out pretty close to 220µH.