Mad Of Science

You might have all came across many electric bells using electromagnet ,this is yet another one with slight modification , a home made electric bell.



Materials Required:

1. Gong ( toy car )
   
2. Hammer (battery cover sheet)
   
3. Electromagnet ( Picture tube coil)
   
4. 9 V battery
5. Simple Switch Mechanism.(hanging wire)
   
6. Pole Supporting Hammer ( pen refill)
   

Electromagnet:

When electric current passes through a coil wound on a soft iron core ,iron acts as a temporary magnet. It acts as a magnet until current passes through it. I got this electromagnet from junk TV picture tube, works perfectly.


More the number of turns ,more the applied voltage the strength of electromagnet will increase.

Gong :

Look for it in some toy cars ,or else take some tensile metal .


Hammer:

Do it yourself. I made one out of a battery cover metal sheet.

Simple Switch Mechanism:

It is the switch mechanism which varies from bell to bell. It depends upon creativity of creator. Many types mechanism are available. I have used hanging type switch. Nothing but a simple strip of wire hanging down touching the hammer.


Whenever the hammer is pulled and released , the circuit opens and closes.

Pole:

A small pole is erected near the electromagnet , bearing spring and holding hammer. I used a pen refill as a pole and a spring around the refill. Which gives the necessary tension to the hammer.




This is how it works . The speed of the hammer can be increased by increasing the power of electromagnet .