176
Experiment
If everything is wired correctly, you will hear a clear tone with a sinusoidal waveform coming from your
Piezo element once the battery is connected. This is a pure tone without any harmonics unlike the complex
tone, which would be composed of several pure tones. This is also the reason why a pure tone sounds arti-
ficial and sterile. In our case, frequency is about 100 Hz. You can use this test signal to check audio circuits.
The circuit diagram for this experiment is shown in Chap. 3, Fig. 3.150.
Circuit 151:
Simple tone generator 100 Hz
Setup information
Install the transistor, the five resistors and the three ceramic capacitors and the electrolytic capacitor as
shown in
Fig. 2.151.
The thirteen jumper wires come next. Last but not least connect the Piezo element.
Check the placement on the board again and only then connect the battery.
You can significantly increase the sensitivity of the Piezo element by using a sound plate or even a sound
box. Read more about it in Chap. 1.2.3
Components required:
1 x 2N3904 transistor,
1 x 47
Ω
resistor,
1 x 2.2 k
Ω
resistor,
2 x 4.7 k
Ω
resistors,
1 x 220 k
Ω
resistor,
3 x 100 nF ceramic
capacitors, 1 x 10 μF
electrolytic capaci-
tor, 1 x Piezo element,
1 x breadboard, 1 x 9V
battery with clip con-
nector
Fig. 2.151:
Simple tone
generator 100 Hz
Experiment
If everything is wired correctly, you will hear a clear tone with a sinusoidal waveform coming from your
Piezo element once the battery is connected. This is a pure tone without any harmonics unlike the complex
Summary of Contents for ELECTRONICS EXPERIMENTS BOX
Page 4: ......
Page 265: ...267 Fig 3 56 Cir cuit 56 Audio limiter Fig 3 57 Circuit 57 Amplifier for a storm detector...
Page 269: ...271 Fig 3 64 Circuit 64 Stabilizer for 1 9 V Fig 3 65 Circuit 65 Stabilizer for 2 5 V...
Page 275: ...277 Fig 3 80 Circuit 80 Quiztimer 30 seconds Fig 3 81 Circuit 81 Handy diode tester...
Page 315: ...317 Fig 3 179 Circuit 179 HF generator 150 kHz Fig 3 180 Circuit 180 HF generator 420 kHz...
