Here is the schematic, PC board pattern, and parts placement for a "Fantastic Atom Expander". This circuit produces an "exploding atom" effect using 98 LEDs.
| C1 | 1 | 0.1uf Mylar Capacitor | 0.1uF Ceramic Disc Capacitor |
| IC1 | 1 | 4017 IC | |
| IC2 | 1 | 555 Timer IC | |
| L1-L98 | 98 | Jumbo LED (any colour but blue) | |
| Q1-Q5 | 5 | 2N3904 NPN Transistor | |
| R1 | 1 | 4.7k Resistor | |
| R2 | 1 | 680k Resistor | |
| R3-R7 | 4 | 470 Ohm Resistor | |
| MISC | 1 | PC Board, 9V Battery Snap, IC Sockets |
1. The LEDs can be any colour but blue. For a very interesting effect, make one ring red, the next one green, the next one orange, then yellow, etc.
2. The transistors can be most any inexpensive NPN transistor (2N2222, PN2222A, Etc.).
3. For a very interesting (and expensive!) effect, replace the 2N3904's with 2N3055 power transistors on heatsinks and use 12 V 500ma incandescent bulbs instead of LEDs.