Now, if we reverse the polarity of the battery, the direction of the current changes, consequently poles of the electromagnet are reversed, and the direction of magnetic lines of force also gets reversed. And magnetic lines flow from N to S pole. This electromagnet has its North Pole, N, and South Pole, S, like a conventional magnet. When the switch S is turned on, current starts flowing through the inductor, a magnetic field is produced and the inductor becomes an electromagnet. Let us take a simple circuit as shown in Figure 2, where a battery is connected to an inductor L in parallel, and a switch S in series. It is denoted by the letter L and its SI unit is Henry, H.įigure 1 depicts the symbol of an inductor.įigure 1: Symbol of Inductor Working of Inductor It could be a tiny piece of straight copper wire or wire wound into rings called a coil.Īn inductor inherently opposes the change of current through it. What is an Inductor?Īn inductor is a two-pin passive component that stores energy in the form of a magnetic field when a current flows through it. Let us take a deep dive into the world of inductors. Things are not that exact with this.Inductors are vastly used from mobile, laptop chargers to high-end communication equipment like mobile base stations to the satellites orbiting the earth. If forms that fit the model are not available, you can interpolate by the forms that are larger or smaller. If possible, try to keep the DC resistance below 1 ohm, even 1/2 ohm if possible. The 18 gauge wire has about a third of the cross-sectional area of the 14 gauge, and shoud cost commensurately less-but have higher DC resistance. Suffice it to say, American gauge 14 thru 18 are the best choices. I would post the chart, but it dies not fit with the posting parameters of this BB program. I believe the chart is in American gauge wire. Note that the wire diameter, in Metric, is included so you can get the right gauge. Note: I believe the wire gauges are somewhat different in America and India. Using that program, here are wire guages, forms, etc. If you are using an 8 ohm speaker and a 12dB/octave crossover, you want the inductor to be about 12 ohms at the crossover frequency. The men in the white coats should be coming for me any moment now. Yesterday I posted a long message telling you I was going to to give you the link to an air core inductor calculator. Let us know how you are making out on the project! You would have to knowĪ) the permeability of the ferrite you are working withī) the inductance of a given ferrite inductor and just calculate how many more turns are required to change it. Other forms of ferrite require more turns of wire-less than air core inductors, of course-but give low distortion that begins to approach air core inductors. Some ferrite cores add a lot of distortion but gives you a lot of inductance for a comparatively few turns. However, there is one thing-there are different kinds of ferrite. I might be able to dig up something for a ferrite core inductor. If you plan on crossing over at 500 Hz or above, then air core inductors are a reasonable way to go. Say dhar, just how big an inductor do you need? Alternatively, where are you trying to cross over? If you are looking to crossover at 100 Hz, then air core inductors might be simply too big. Fill in the desired value in a box-bing!-get the number of turns you need. If you have decided to go air core, this is one more program to help you. I am sure the CAL SOD program is good, but this is one more option. Well, it's a little late, but I could not help but post this real easy air core inductor calculation program I came across.