Bursts Of Light - Maker Factory ELECTRONICS EXPERIMENTS BOX Manual

The circuit diagram for this experiment is shown in Chap. 3, Fig. 3.92.

2.39 Bursts of light

Circuit 93: Fast LED flash
Setup information
Install the two transistors, the LED, the three resistors and the two electrolytic capacitors as shown in
Fig. 2.93 followed by the eight jumper wires. Check the placement on the board again and only then con-
nect the battery.
Experiment
If everything is wired correctly, the circuit immediately starts generating very short LED flashes at an interval
of about one second. The repetition frequency in our circuit is basically defined by C2. Circuitries of this
kind can be used as a stroboscope in many applications.
The circuit diagram for this experiment is shown in Chap. 3, Fig. 3.93.
118
Components required:
1 x 2N3904 transistor,
1 x 2N3906 transistor,
1 x red LED, 1 x 100 Ω
resistor, 1 x 100 kΩ
resistor, 1 x 220 kΩ
resistor, 1 x 1 μF electro-
lytic capacitor, 1 x 10 μF
electrolytic capacitor,
1 x breadboard, 1 x 9V
battery with clip con-
nector
Fig. 2.93: Fast LED flash