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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 |
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Related Circuits |
Comments |
| 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. | ||
| 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. | ||
| ## 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. | ||
| 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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| .can i lessen the no. of led's use?and what would be the adjustments in using only half of 98leds. | ||
| looks like a really fun project. it there anyway i can build to use blue leds? any info would be very helpful. thank you | ||
| i just want to know
will this thing work or not (Editor's notes: Yes.) |
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| This circuit "OR-ties" the outputs of the 4017 counter, which is not the best methodology. The circuit should be modified to include OR gates (either sections of type 4071 ICs or discrete diode-resistor gates). Otherwise, the 4017 will be stressed and may burn out. Also, many types of 555 timer ICs, when used as a clock, may cause unreliable counting in the 4017. Use a clock comprised of one section of a 40106, along with a resistor and capacitor, instead. | ||
| It*s verry OK ! | ||
| the layout for the ic is too small..i suggest using a matrix board.. | ||
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