| The operation of induction motors, like those used for driving most refrigerators and air conditioning compressors, relies on the principles of electromagnetic induction.
Electromagnetic induction uses the magnetisation of one material by a permanent magnet. The Permanent magnet creates a magnetic field from electric current flowing through a solenoid coil as shown in figures 5 through to 7. |
 Fig 8 The constant rising and collapsing of the magnetic field produces the effect of wires cutting across a magnetic field |
| To illustrate the principles of Electromagnetic induction the diagram shown in Fig 8 contains two electrically separate circuits. Circuit A which is electrically isolated from circuit B is connected to an AC power source through switch S. When the switch is closed an alternating current will flow through the inductor and light the load Lamp A. See illustration in Fig 8b Although lamp b is shown pulsing as the current ebbs and flows, in reality this would not be seen by the naked eye since the current alternates at 50 KHz or 50 thousand times each second. | An alternating magnetic field is set up around coil A which induces an alternating magnetic field in coil B. The animation in Fig 8b illustrates magnetic induction powering lamp b, the basic principle of electric generators and the operation of a transformer |
