Over the holidays I built a white noise machine for my food-frakking deputy Julia. You never know when you might need to drown out some ambient noise.
I’ve used an old coffeecan as a project enclosure, even though I really shouldn’t. When the circuit boards have a chance to move around inside the tangle of wires, the capacitors and other parts have a tendency to pick up signals that muddy up the sound.
It’s based on the premise that if you put a transistor into the circuit the wrong way, it emits a chaotic power signal, which I then feed through a pair of audio amp IC chips.
The variable potentiometer controls the amount of current bridging over the transistor, in effect tuning the sound.
On top you can see where I glued a sponge on top of the speaker to further smooth out the noise quality. Without the muffling, Julia says it sounds like doom.
And of course there are a number of LED status lights. Because you need LED status lights.
This is what it sounds like.
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