Plasma Speaker (Senior Design Project)

While still enrolled at Wake Technical Community College as an electrician, I never graduated because I moved on to a 4 years school after I graduated high school; however I did take enough courses that my electronics professor let me take senior design. So I set out right away to build a circuit designed to do one of the most interesting tasks: produce sound by change the air pressure, not with moving parts and magnatism we are familiar with in speakers but no moving parts and ionized gas produced with a high enough voltage to overcome and produce a spark across the air gap between two electrodes. When the arc is stuck by high voltage supplied by a flyback transformer, it ionizes the air around it, which has two primary effects: first, the plasma makes a much better conductor that the normal air is, which allows better continuity of the arc, and allows the newly-found conductor to vibrate with varying magnetic fields. Secondly, and probably more importantly, the plasma is relatively massless, and as the current through the arc varies, the higher-resistance air around the plasma stays stuck to it, and is thereby driven by its vibration. As I mentioned, the plasma is relatively massless, so almost no energy is wasted on moving it. This allows for a much clearer, almost perfect, reproduction of the original sound.

However, it is important to note that plasma speakers completely act as a tweeter and can not reproduce bass frequency sounds.

Here is the circuit diagram:







Since at the time I had a lot less theory as I do now, it took me weeks of prototyping to get this project right, but I finally got sound the day before my presentation!

Some photos:


Flyback Driver and electrodes:Image



I’ll have to post a video of it working this weekend along with the schematic I designed myself to power the device.



About craiggleso

B.S. Industrial Management - Grove City College Studied Applied Electronics at Wake Technical Community College
This entry was posted in Uncategorized. Bookmark the permalink.

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google+ photo

You are commenting using your Google+ account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )


Connecting to %s