Instructables: Build An Optical Theremin

An Instructables by Sacred


What is a theremin? It is an instrument that can be played without being touched. Traditional theremins use antennas and oscillators to sense a person's hand and generate a tone. Ours will use light instead. Because of this, it is not an actual theremin, it just uses similar principles. As a side note, this is my first instructable, so please be nice.
Instructables Logo

A Real Theremin


Original Optical Theremin
The Original Optical Theremin


Step 1: Gather Materials

This needs very few parts, I made mine for under $20.
Here is what you need:

Qty.
Part Description Manufacturer Part Number
2
Phototransistors UT1893-91-0125-R
1
TLC555 Timer IC TLC555CP
1
.047µF Capacitor DC.047B
1
100µF Capacitor RA100/16-R
1
1MΩ Resistor CF1/4W105JRC
1
10kΩ Resistor CF1/4W103JRC
1
Battery Pack (to fit 4 AA) SBH-341-1AS-R
4
AA Batteries ALK AA (EN91)
1
Hook-up Wire #9313-0-R
1
Breadboard WBU-301-R
1
Small Speaker KWT2340F12L-2E
1
Wire Stripper JE-2022C-R


Phototransistors
These are not LEDs. They are phototransistors.
Make sure you get the right thing!
Resistors
1MΩ Resistors and 10kΩ Resistors

IC Socket
The TLC555 IC timer. Mine is an IC socket.
I recommend getting a socket for your chip.

.047µF Capacitor
The .047µF capacitor reminds me of chiclets.

100µF Capacitor
100µF Capacitor

Battery Pack and Breadboard
My battery pack has an on/off switch built right into it.
Very convenient. Above is a breadboard.

Wire
Wire! I got mine from telephone line and when you strip
off the outer casing, there's four strands of wire inside.

Speaker
My cheap little speaker. It's terrible, but it manages.


Step 2: Putting it Together

This is a really easy circuit to build. Just make sure you follow the directions, and yes, the image came from Instructables.com.

RS Optical Theremin


Step 3: The Finished Product and Video

At this point in the game, everything should be working. Congratulations on the build, have fun with it!

Optical Theremin
If you have an electronics story or project you'd like to share, please email MyStory@Jameco.com