Instructables: Build An Optical Theremin An Instructables by Sacred Table of Contents Intro: How To Build An Optical Theremin Step 1: Gather Materials! Step 2: Putting it together Step 3: The Finished Product and Video Intro: How To Build An Optical Theremin

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.

Here is a video of a real thermin:



This is where I learned how to do this:

The original optical theremin



Step 1: Gather Materials! (top)
This needs very few parts, I made mine for under $20.
Here is what you need:

Tools List	Mfr P/N	Jameco P/N
Two phototransistors	UT1893-91-0125-R	373001
One TLC555 timer IC	TLC555CP	761272
One .047µF capacitor	DC.047B	1947351
One 100µF capacitor	RA100/16-R	330422
One 1MΩ resistor	CF1/4W105JRC	691585
One 10kΩ resistor	CF1/4W103JRC	691104
One Battery pack (to fit 4 AA)	SBH-341-1AS-R	216187
Four AA batteries	ALK AA (EN91)	198707
Hook-up wire	#9313-0-R	36792
One breadboard	WBU-301-R	20601
One small speaker	KWT2340F12L-2E	336314
Tools:
Wire stripper	JE-2022C-R	215889

Image Notes 1. These are not LEDs. They are phototransistors. Make sure you get the right thing!	Image Notes 1. 1MΩ Resistors 2. 10kΩ Resistors
Image Notes 1. The TLC555 IC timer. Mine is an IC socket. I recommend getting a socket for your chip.	Image Notes 1. The .047µF Capacitor. It reminds me of chicklets.
Image Notes 1. The 100µF capacitor	Image Notes 1. My battery pack. It has an on/off switch built right into it. Very convenient. 2. This is a breadboard.
Image Notes 1. Wire! I got mine from telephone line. Its sold by the foot at most hardware stores for a low price, and when you strip off the outer casing, theres 4 strands of wire inside.	Image Notes 1. My cheap little speaker. It's terrible, but it manages.

Step 2: Putting it together (top)
This is a really easy circuit to build. Just make sure you follow the directions. If any problems come up, I'll gladly try to help you out. Just send me a message. And yes, the image came from Instructables.com. It's a fascinating website.




Step 3: The Finished Product and Video (top)
At this point in the game, everything should be working. Congratulations on the build, have fun with it!

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