Fantastic Atom Expander
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 |
- 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.
- The transistors can be most any inexpensive NPN transistor (2N2222, PN2222A, Etc.).
- 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.