It’s So Easy To Make A Speaker At Home!

By Anupum Pant

While doing a random experiment with the ordinary motor, a youtuber Andy Elliott who runs the channel mist8k (known for his awesome videos) mistakenly touched the 3.5 mm jack of a speaker cable to the motor’s wires.

This resulted in something very interesting. The sound being transmitted through the cable started coming from the motor. And consequently, he invented the very basic speaker. Then he made a video of him explaining how to make a speaker at home using just a copper wire, magnet, tape, jacks and a disposable plastic cup.

I first saw this on Gizmodo and I thought it deserved a mention in the engineering section of this blog. I can’t wait to try it myself and probably improve the “very basic speaker” to make a nice iPod dock in the future…

Here is what he does –

  • Uncoils a copper wire from a component of an old PC, turns it into a small circular coil of the size of the circular magnet and then tapes it to the back of a disposable plastic cup.
  • Then, makes a larger coil by winding it around a bottle cap and tapes it on top of the smaller coil.
  • Connects one end of the larger coil to the tip of the 3.5 mm jack and the other end of the coil to the base of the jack. The other end of this wire having the 3.5 mm jack is also a 3.5 mm jack, which goes into the computer’s (or any player’s) speaker plug.
  • Places a strong neodymium magnet on top of the coils and plays the music. That’s it!

The computer turns the sound signal into an electric current. This current flows into the jack and then into the coil. Thus, the coil produces a magnetic field of its own. This varying magnetic field coupled with the static magnetic field of the neodymium magnet makes the coil move. Which in turn moves the back of the cup (as it’s taped on it) and makes the air vibrate. As a result, sound is created.

Here’s the video where he teaches how to do it…

A Fan With No Blades

By Anupum Pant

Fans have always had blades which chop up the air and send a turbulent gush towards you. Also, “you can’t put your head or hand through the traditional fan”. Although these things aren’t big problems that the device says it’d solve, I still like how different and innovative this thing is. Certainly worthy of sharing in my engineering section…

This one, one of the many amazing things invented by sir James Dyson, is a blade-less fan. Or as the man likes to call his invention – an air multiplier. As the name suggests, the device has no blades and yet it is capable of shooting out a steady stream of air on your face.

It’s amazing how it works. Watch Sir James Dyson himself explain it to you.

A Man-Made Leaf

By Anupum Pant

Julian Melchiorri, a graduate student from Royal College of art, claims to have fabricated the first ever man-made biological leaf which absorbs water & carbon dioxide, just like a leaf does, and produces oxygen.

It looks like a promising first step towards enabling longer distance space travel – in a way that the artificial leaf made by him could be used to supply oxygen in micro-gravity, in which terrestrial plants have a hard time growing.

The artificial leaf he made for his project involves extracted chloroplasts from plant cells laid on a matrix of silk protein.

The “first man-made biological leaf” could enable humans to colonise space from Dezeen on Vimeo.