Fireworks - Maker Factory ELECTRONICS EXPERIMENTS BOX Manual

2.38 Fireworks

Circuit 92: LED firework
Setup information
Install the two transistors, the three LEDs from your experiment box, the four resistors and the two electro-
lytic capacitors as shown in Fig. 2.92. If you find another LED in your own hobby box such as a red one,
go ahead and use it. If not, simply use the IR diode from the experiments box. The nine jumper wires come
next. Check the placement on the board again and only then connect the battery.
Experiment
Your LED fireworks start instantly, if everything is wired correctly. In quick succession, one pair of LED will
flash up. The effect is amazing, especially if you have a criss-cross arrangement, and even more so in a
darkened room.
Components required:
2 x 2N3904 transistors,
1 x red LED, 1 x yellow
LED, 1 x green LED,
2 x 1 kΩ resistors,
2 x 100 kΩ resis-
tors, 1 x 1 μF elec-
trolytic capacitor,
1 x breadboard, 1 x 9V
battery with clip con-
nector
Fig. 2.92: LED fireworks
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