Instructables

Draw Minty Electronic Music

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Picture of Draw Minty Electronic Music
altoid000.JPG
This is taking a previous breadboard experiment and installing it in an Altoids tin.

Along the way I include a few tips about soldering.

A few things different from the breadboard project:
I used a toggle switch instead of a slider.

I added an LED so that you could tell if the power is on.  This is important because this unit is portable and operates on battery instead of a steady power supply.  If the LED goes dim you will want to replace the battery.  The downside to using a battery is that the sound will change pitch as the battery weakens.

All the connections are permanently soldered.

The components are hot-glued to secure them and to insulate them from shorting on other components and the side of the tin.

Consider:
You may want longer probe wires so you can stretch across larger drawings.

Parts Needed:

Power supply (a 9 volt battery and connector)
Wires (an assortment of sizes with the ends trimmed bare and tinned would help)
Small Switch (on-off or on-on will work fine)
Speaker 16 Ohm 25 W (Actually just about any little old speaker will work)
Audio Transformer (you can pick one up at Radio Shack for about $3) [Model: EI-19 Catalog #: 273-1380, Frequency response: 300Hz to 10kHz, 1,000-ohm center-tapped primary, 8-ohm secondary, Low-level impedance matching]
Transistor 2N3904
Capacitor Ceramic 0.047uF
Resistor 10K
Resistor 3.3K
Paper (a nice piece of card stock would be nice)
No 2 Pencil

notes:
For so many of my projects I scavenge my parts from old electronics that are worn out.  That saves a tiny fortune on parts but the cost of most of these parts brand new is probably under $10 especially if you order from a place like http://www.taydaelectronics.com
I was disappointed they didn't have the Audio Transformer but I did look it up and found it available at Radio Shack.
 
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rachl00912 months ago
Here's mine!

A few things I did different:
-I put the speaker on the top lid and sanded the paint off it.
-Used stranded wire for the probes and soldered solid wire ends on, then covered them with heat shrink.
-I also tried a few different speakers, the one that worked the best was a speaker like the one you used, except mine is 8 ohms instead of 16. I tried a piezo, and a small loudspeaker that had plastic instead of the black paper, they were both not very loud.
pencil music drawer.JPGpencil music drawer.JPG
Kepster (author)  rachl00912 months ago
That looks great!

:D
ljochoam11 months ago
Excellent!
rachl0091 year ago
what happens if you touch the two probes together? does it damage anything?
Kepster (author)  rachl0091 year ago
You may freely touch the two probes together. When you do it makes the highest pitched tone that this device can make. When you touch the probes to a line drawn with a no 2 pencil (generally) the farther apart the two probes are then the lower the pitch. The width of the line also affects the pitch as well as the amount of graphite built up on the paper (i.e. if you scribble a darker line it should make the pitch higher). Experiment to your hearts content.
Love music but not so much mints!! But still awesome!!!!!
Great tips