The Induction Coil Experiment
Starredreviews is presenting you an interesting experiment which is simple to understand the basic concepts in electronics. Theoretically copper wire coil winded on a thick iron bar can induce electricity while knocking with a magnet bar (this magnet bar can be obtained from old speakers of any appliance in your home)
The Circuit Diagram
Make 1000 turns of copper coil on a thick iron bar. Connect a diode and LED to the connection leads. Diode ensures unidirectional flow of current to LED. While knocking on the iron bar with a permanent magnet, the LED glows. This is a simple and gentle way of showing electromagnetic induction. You can avoid the diode, but the LED glows only using single way current from the AC output flow obtained while knocking the magnet on top. If you are using a bipolar LED or a multicolor LED, all colors will glow at the same time without the diode in this circuit. Diode can filter the current to a single direction DC (Direct current) and gives a rectified output. Always use thin insulated copper wires to make the turns.
At a glance
1. Use magnet pieces obtained from old audio speakers.
2. Thin coil can be obtained by unwinding the thin primary coil of ac to dc adaptor.
3. Make more turns on a thick iron bar to maximize the output voltage while hitting the iron bar with magnet.
4. If using a diode in circuit, please ensure the correct polarity of LED terminals.
5. Make the windings tightly.
6. After making the turns just show the ends of copper coil to a lighted candle or cigarette lamp to remove the insulation. You can also scratch the tip part with a blade to do the same.