Over the years my first simple electronic project has been published as a web standard. Visit Make Magazine
|Note: Q1 & Q2 could be replaced with a single CdS LDR light dependant resistor removed from a wall plug night light.|
Board size 1.6" x 1.8" (40mm x 45mm)
PDF (168k) <= Etch your board using this file.
Go sub-sonic and shake the walls!
If bread boarding the phototransistors must be opposite to one another as in the schematic.
The phototransistors physically mount on the etched circuit board in the same direction. Look for the fat internal lead (collector). Either direction is fine as long as both transistors are the same.
You need a black plastic sleeve around the phototransistors to block the
light coming from the sides. This will make the light exposure more directional
toward the phototransistors front lenses.
A triangular waveform which creates a better tone is generated at pins 2 & 6 which is the top connection of C1 of the TLC555. This can be made useable by tapping off here and driving the high impedance input of an additional Op-Amp like a TL082. This Op-Amp is needed for isolation of the triangular wave to avoid loading down the performance of the TLC555 circuit. You might also try feeding the signal from here to your main amplifier, if it does not work it will distort the frequency of the sound.
|RS Theremin Says "Hello World"|
|C1||.047 uf||1||272-1068||1.29||1||1.29||Pack has two|
|IC Sockets||8 Pin||1||276-1995||0.69||1||0.69||Use a Socket !|
|PC Board||Generic||1||276-159||2.29||1||2.29||Etch your own PDF (168k)|
|V1 Battery||4 AA Holder||1||270-409||1.89||1||1.89||Switch in Battery Holder|
|Line Out||PC Board Term.||1||276-1388||2.29||1||xx||Optional Pack of 4|
|Prices as of Sept. 25, 2004||US Dollars||Total||=||14.30||<=Batteries Not Included (-;|