555 Square-Wave Theremin




Introduction: 555 Square-Wave Theremin

About: I'm a 18 year-old guy who loves tinkering with and building electronics. I am self taught (in terms of electricity), my grandpa was an electrician, and a vein in my left hand makes the symbol for alternatin...

For this project, you will need:
10k ohm resistor
10 megohm resistor
A 3.9k or 4.7k ohm resistor 
555 Timer ic & socket
2N3904 NPN transistor 
.01u ceramic capacitor
USB cable
Piezoelectric speaker
photo-transistor (or other type of input, pot's and skin work fine)
wires and connectors 

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Step 1: Schematic

Since i didn't take pictures while i was making it, here's the schematic (better than pictures in my opinion). 

Step 2: Finished Product

Step 3: For Added Effect

use an arduino board and solid-state relays for a synthesizer effect. or use push buttons and resistors for a more simple synthesizer like i did. or even better, find a way to combine both!  i had a picture to add, but the uploader was on the fritz. :(

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    4 Discussions


    7 years ago on Step 2

    I thought 555s were supposed to handle 5v to 12v? I've put 12v through 555s more times than I can count.


    That last step would be a great place for a video if you could make one.


    Reply 8 years ago on Introduction

    yes, i agree i will try to add one if the uploader will work.