(13 Reviews)
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This kit, though is great, could use some ic sockets for the chips so they can not be wrecked by heat from soldering. Also the kit could come in different color leds like blue and green.
Get a bag of ten 2N2222 NPN transistors. Connect the Base of transistor as the anode lead of the LED onto circuit board, and the Emitter lead where the cathode of the LED is supposed to go on the circuit board. The Collector leads of the transistors and the positive supply now become the two point where you should now connect the LEDs instead - with anode of LED to the positive supply and the cathode of LED to the Colector leads of each transistor. To make the high tech back and forth scanning of LEDs rather than the monotonous one way running lights, you will need only 6 LEDs. Just short the transistor collector leads of 7th output with the 5th, the 8th output with the 4th, the 9th output with the 3rd, and the 10th output with the 2nd. The ten transistors will activate the Collector current sequentially all the time, but in this instance the 6 LEDs will be lit 10 times in a back and forth manner in this sequence - 1, 2, 3, 4, 5, 6, 5, 4, 3, 2 and cycle repeats back at 1 giving a back and forth scanning visual. If you need to control light bulbs, instead of LEDs, get the reed relays instead. And BTW, if you are using a 5V supply instead of 9V batteries (which I tap the 5V from my PC supply), short the 330ohm resistor to activate the reed relay switches.
The LONG end of the LEDs that came with the kit is NEGATIVE, contrary to the LEDs you will find at Radio Shack. Also, using an oscilloscope, we found excessive noise coming upstream from the 555 chip which caused erratic flashing; A 9 volt capacitor solved that problem.
The flashing lights look pretty cool when finished. It was easy to put together, except for the IC's. They fried when I tried soldering them. While you're paying the shipping,you might as well buy two cheap IC sockets.
I don't know what the IC problems were with the other reviews, but I had this circuit together, soldered, and fully functional in less than 5 minutes! Great circuit & easy to follow instructions. This can be assembled with very little electronics knowledge!
| 100 + | $0.40 each |
| 100 + | $0.15 each |
| 100 + | $0.20 each |
| 500 + | $0.18 each |
| 1000 + | $0.14 each |
