The electric bell was first invented by British physicists in the mid 1800s following the invention of electromagnets. When current was passed through the wire, it creates an electromagnetic force which made the bell arm swing sideway and hit the bell, which then broke the current arm fell back. This action repeats, which causes vibration of the arm.
Through this DIY kit, you can build an unique electric bell of your own. The bell is made of inner pot of rice cooker and the wooden board came from wine boxes. All upcycled materials are collected from Hong Kong.
Download: [Electric Door Bell Instruction]