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]
Capacitor Ceramic 0.047uF
Paper (a nice piece of card stock would be nice)
No 2 Pencilnotes:
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.