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.

Schematic

PC Board Layout

Parts Placement

Parts

Part Total Qty. Description Substitutions 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

Notes

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.