Portable Generator For Sale

How can I make an electric generator that does not use a permanent magnet?

There are lots of places to find methods of making small generators that use permanent magnets, but I have always wondered how they do it when there aren't any such magnets available.

Public Comments

1. Large commercial generators do not have permanent magnets. The rotating field is magnetized via slip rings that feed current into it's windings. The current is generated by the exciter which is either a small generator attached to the end of the shaft or, in modern applications, an electronic SCR converter.
2. The altenator on your car uses the very method that you are asking about. You use an electromagnet instead of a permanent magnet. As you vary the current through the coils of the electromagnet, the magnetic field will increase or decrease, and that will in turn lead to more or less current being generated from the altenator.
3. First of all which generator u want to make ( induction, synchronous generator). Large generators are mostly made of, using coil wrapped on a ferromagnetic material to produce flux which is alternate of using permanent magnet. This coil is normally energized by external source which convert it into electromagnet. e.g Solenoid. Moreover we have more control on flux in the electromagnet case. If u need more details i will email u a file.
4. You can develop a generator without using a permanent magnet. Use of coil assembly would and supply elctricity would turn in to an electromanget and on moving this electromagnet with a second coil would produce elctricity from the second coil