This is my first project on instructables .
I would like to show you how to make a working electrical telephone that does not need any power to function .
I hope that you can read and understand the schematic diagram . I am sorry , but it was already built so i could not make step by step .
This device is simple to build , so anyone can make one . Sure , this device does not ring like conventional telephone , but with some modification , you could add some ring and a dynamo to power the ring while calling , but that is up to you . Earpieces used in this project are high impedance . I did not measure them , but i think that they are around 600 Ohm from used telephone .
Note that when speaking the sound is not very loud , so i think that loud people will not have problems using it :)
I suggest using it in a quiet environment .
Well , i dont see any practical use for this device so you will have to figure out where and how to use it .
But kids like it .