Intro

I'm gonna build a transducer. The aim is to have a little fun and learn some stuff along the way. Then take over the world with my new best-driver-in-the-world.

This web page will be diary of my research activities.

Warning: This project is about trial and error, a little scientific exploration and a lot of guesswork. I'm literally starting from scratch armed only with my desire to have fun and learn. I may end up nowhere - I may end up somewhere. Any help, pointers, criticisms are all appreciated: vikash@purplecoral.com

Materials

Materials for the job. Well, to begin with at least.

0.265mm (approx 30 awg) enammelled copper wire and 10 neodymium disk magnets (10mm x 5mm). These little things are strong for their size. Try to pull them apart a couple of times and you're sure to have sore fingers. They pull 2.5Kg in contact, and 0.9Kg in a 1mm air gap.

Transducer in a hurry v1

Ok, sanity check. Let me prove to myself that this magnetic/electromagnet phenomenon actually works. Should have payed more attention at school...

Yes, I actually used the inside of some bog roll - and crudely wound some wire around it. It measured in at 4.5 Ohms.

I'm in a hurry to get some sound, any sound, so I just threw the magnets in the middle of the roll and hoped it would be enough to excite my bog roll coil.

Woohoo. I think I just made the most inefficient speaker ever. But I can hear sound, and i'm satisfied. Watch out all you driver manufacturers, i'm a coming...

Magnet Circuit Design

Ok, so now the inital excitement's over and I've got round to making a serious first design cad drawing. Features: 30mm T-shaped vented pole. 5mm trench to allow former travel. 1.2mm air gap.

Well it looks cool, I have to give it that. While I wait for my uncle to machine the front & back plate, and pole piece, I think I'll take my bog roll speaker a step further.