Fantastic Atom Expander

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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

This is the printed circuit layout for the Fantastic Atom Expander

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

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.

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Comments

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anonymous Fantastic Atom Expander Sunday, August 02, 2009 5:20:54 PM

J means Jumper

anonymous Fantastic Atom Expander Thursday, April 16, 2009 10:34:22 AM

What yhe J letter means? It appears like J1, J2, J3, J4, J5 and J6! Thanks!

João Silva Brito Fantastic Atom Expander Thursday, April 16, 2009 9:59:32 AM

It's just me or its missing from the parts placement de led place or number 85. From my count is 97 leds not 98!?!? Please advise!

João Silva Brito Fantastic Atom Expander Thursday, April 16, 2009 7:02:54 AM

Hello! Could you please send me or improve the showned Schematic because i can't see all the numbers in the ICs. It's really important! Thank's!

ChrisWhewell Fantastic Atom Expander Friday, January 23, 2009 10:38:13 AM

Is it a one-shot deal, or does it provide a continuous series of expanding light effect ? Thanks

suraj Fantastic Atom Expander Tuesday, October 14, 2008 12:41:35 AM

circuit diagram is not clear

anonymous Fantastic Atom Expander Wednesday, April 23, 2008 12:59:36 AM

I built my atom expander following the design on this page. But it didn't work at first because the capacitor was to small. Eventully after trying many capacitors a 220pf(0.22uf) worked and gave me a working project. So i don't know what happend, everything else is right it was just the capacitor. oh well, anybody building the project, if it doesn't work and the ic's are working make the capacitor a bit bigger like a 220pf.

RedWagnum Fantastic Atom Expander Saturday, March 15, 2008 8:27:24 PM

This circuit works very well! I bought a couple of these in kit form from electronicsgoldmine.com a couple of years back. I substituted ultra-bright LEDs for the "100 for a buck" red ones that came with the kit. Red on the outer ring, then amber, green, blue, pink (yes PINK), and then an 8mm white in the center. Changed resistor values where needed and it works just great. I've run it from various voltage sources anywhere from 6V to 12V with no problems. The transistors get a little warm but the duty cycle is low enough that it is not an issue.

SeanFalloy Fantastic Atom Expander Thursday, March 13, 2008 2:17:00 PM

## ali ##This circuit will never WORK! because u need to use 8 diode on out pins the output is triggering a transistor which will amplify the signal to usable levels without the draw on the output Pins.

jparker Fantastic Atom Expander Thursday, December 27, 2007 8:59:46 AM

You cannot combine colors on the same circuit; LED's are not lamps. They are non-linear devices. Reds want to drop about 1.8 volts, yellow about 2 volts, green 2.1 (new technology green ~3.5), and blue ~3.5 volts. You can usually get by parallelling the same color on one circuit, but they won't all be the same brightness (and one might burn out). Parallelling for example a red and a green, the red gets all the current (because of its lower voltage drop). Being non-linear, the best circuit is a series resistor for each LED --- the LED will set its own voltage. Calculate the series resistor by taking the supply voltage, subtract the LED voltage, and divide the result by the current (.010 amps for most LED's). If you use only one resistor per color, then multiply the current (.010 amps) by the number of LED's (24 for the outter ring). Example: Blue LED R = (Vs - Vled) / I led R = (9 - 3.5) / (.01)(24) R = 5.5/.24 R = 23 ohms Be sure the resistor can handle the power: P = (I**2)(R) P = (.0576)(23) P = 1.3 watts I suggest a chip resistor for EACH Light Emitting Diode. LES's will be safer, resistors cooler, and the world geopolitically safer (maybe not the last one)...
(Editor's notes: Just a note that the version I made with a rainbow of different LEDs has been working fine for over 10 years.)

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anonymous	Fantastic Atom Expander	Sunday, August 02, 2009 5:20:54 PM
J means Jumper
anonymous	Fantastic Atom Expander	Thursday, April 16, 2009 10:34:22 AM
What yhe J letter means? It appears like J1, J2, J3, J4, J5 and J6! Thanks!
João Silva Brito	Fantastic Atom Expander	Thursday, April 16, 2009 9:59:32 AM
It's just me or its missing from the parts placement de led place or number 85. From my count is 97 leds not 98!?!? Please advise!
João Silva Brito	Fantastic Atom Expander	Thursday, April 16, 2009 7:02:54 AM
Hello! Could you please send me or improve the showned Schematic because i can't see all the numbers in the ICs. It's really important! Thank's!
ChrisWhewell	Fantastic Atom Expander	Friday, January 23, 2009 10:38:13 AM
Is it a one-shot deal, or does it provide a continuous series of expanding light effect ? Thanks
suraj	Fantastic Atom Expander	Tuesday, October 14, 2008 12:41:35 AM
circuit diagram is not clear
anonymous	Fantastic Atom Expander	Wednesday, April 23, 2008 12:59:36 AM
I built my atom expander following the design on this page. But it didn't work at first because the capacitor was to small. Eventully after trying many capacitors a 220pf(0.22uf) worked and gave me a working project. So i don't know what happend, everything else is right it was just the capacitor. oh well, anybody building the project, if it doesn't work and the ic's are working make the capacitor a bit bigger like a 220pf.
RedWagnum	Fantastic Atom Expander	Saturday, March 15, 2008 8:27:24 PM
This circuit works very well! I bought a couple of these in kit form from electronicsgoldmine.com a couple of years back. I substituted ultra-bright LEDs for the "100 for a buck" red ones that came with the kit. Red on the outer ring, then amber, green, blue, pink (yes PINK), and then an 8mm white in the center. Changed resistor values where needed and it works just great. I've run it from various voltage sources anywhere from 6V to 12V with no problems. The transistors get a little warm but the duty cycle is low enough that it is not an issue.
SeanFalloy	Fantastic Atom Expander	Thursday, March 13, 2008 2:17:00 PM
## ali ##This circuit will never WORK! because u need to use 8 diode on out pins the output is triggering a transistor which will amplify the signal to usable levels without the draw on the output Pins.
jparker	Fantastic Atom Expander	Thursday, December 27, 2007 8:59:46 AM
You cannot combine colors on the same circuit; LED's are not lamps. They are non-linear devices. Reds want to drop about 1.8 volts, yellow about 2 volts, green 2.1 (new technology green ~3.5), and blue ~3.5 volts. You can usually get by parallelling the same color on one circuit, but they won't all be the same brightness (and one might burn out). Parallelling for example a red and a green, the red gets all the current (because of its lower voltage drop). Being non-linear, the best circuit is a series resistor for each LED --- the LED will set its own voltage. Calculate the series resistor by taking the supply voltage, subtract the LED voltage, and divide the result by the current (.010 amps for most LED's). If you use only one resistor per color, then multiply the current (.010 amps) by the number of LED's (24 for the outter ring). Example: Blue LED R = (Vs - Vled) / I led R = (9 - 3.5) / (.01)(24) R = 5.5/.24 R = 23 ohms Be sure the resistor can handle the power: P = (I**2)(R) P = (.0576)(23) P = 1.3 watts I suggest a chip resistor for EACH Light Emitting Diode. LES's will be safer, resistors cooler, and the world geopolitically safer (maybe not the last one)... (Editor's notes: Just a note that the version I made with a rainbow of different LEDs has been working fine for over 10 years.)