Demonstrate effects of electromagnetically induced currents.
- Energetic classroom demonstration of induced currents
Lenz’s Law comes to life with this innovative device. The Ring Launcher consists of a vertically mounted solenoid of thick copper wire with an iron core made up of a bundle of thin iron rods. The coil can be briefly energized with 110VAC by pressing the Launch button on the control panel. For student safety, an electronic circuit ensures that the coil is only energized one time briefly for each separate button press, no matter how long the button is held down. A series of rings is also supplied with the apparatus — these rings fit over the solenoid and are supported at some height above the base by an adjustable collar. The behavior of the rings when the coil is energized depends on the material of the ring placed over the coil at the time, and can be explained using concepts of electromagnetic induction, including Lenz’s law. The unit also includes a large display which graphs the voltage and current in increments of 50 milliseconds. With this data, the charge and discharge of the unit can be easily seen. Additionally, a secondary coil is provided with 200 and 700 turns so investigations into transformers can also be studied. A coil of wire with a low voltage lamp bulb attached is available separately — placing this coil over the solenoid coil and energizing illustrates the transformer principle.