Magnetic Circuits

What is a magnetic circuit? To better understand magnetic circuits, a basic understanding of the physical qualities of magnetic circuits will be necessary.A magnetic circuit can be compared with an electric current in which EMF, or voltage, produces a current flow. The ampere-turns (NI), or the magnetomotive force (Fm or mmf), will produce a magnetic flux phi(Figure 1). The mmf can be compared with EMF, and the flux (phi) can be compared to current. Equation (1) is the mathematical representation of magnetomotive force derived using Ohm’s Law, I = E / R.phi = Fm / R = mmf / R……….(1)wherephi = magnetic flux, WbFm = magnetomotive force (mmf),...

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Magnetism

Certain metals and metallic oxides have the ability to attract other metals. This property is called magnetism, and the materials which have this property are called magnets. Some magnets are found naturally while others must be manufactured.Magnetism is a result of electrons spinning on their own axis around the nucleus (Figure 1).Figure 1 Electron Spinning Around Nucleus Produces Magnetic FieldIn magnetic materials, the atoms have certain areas called domains. These domains are aligned such that their electrons tend to spin in the same direction (Figure 2).Figure 2 Magnetic DomainsThe alignment of these domains results in the formation of magnetic...

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Methods Of Producing Voltage (Electricity)

This article provides information on the following methods of producing electricity:• Electrochemistry• Static (friction)• Induction (magnetism)• Piezoelectric (pressure)• Thermal (heat)• Light• Thermionic emissionElectrochemistryChemicals can be combined with certain metals to cause a chemical reaction that will transfer electrons to produce electrical energy. This process works on the electrochemistry principle. One example of this principle is the voltaic chemical cell, shown in Figure 1. A chemical reaction produces and maintains opposite charges on two dissimilar metals that serve as the positive and negative terminals. The metals are in...

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