I included an EAGLE Schematic file of the schematic and a pdf version. Furthermore I have those files hosted on my github account. The schematic was taken from the circuit used in MAKE Magazine's Introduction To Transistors video. The video is a good basic introduction to transistors. However, I don't really understand the inner workings of transistors so I am going to avoid in depth discussions of transistors, instead resorting to links to explain a little more about transistors.
Step 1: What You'll Need
- 20MM Coin-Cell Battery Holder
- 3V 20MM battery (I used Energizer CR2016, but a thicker battery would be preferred. I needed to tape the battery into the casing to maintain a good connection)
- 3mm Red LED (color, size and quantity may vary depending on your card)
- 2N3904 NPN Transistor (any low power BJT NPN Transistor SHOULD work)
- 1/4 Watt Resistors: 220 ohm, 1k ohm, 100k ohm
- A SPST Toggle Switch
- Aluminium Foil
- Electrical Tape
- Nice Paper
- Tracing Paper
- Wire (22 gauge is fine)
- A Card Design
- Solder and Soldering Iron
I included a csv with the bill of materials (including Supplier Part Numbers) and heart.svg the base card I used (Inkscape will open the file for editing).