97
2.30 Low pass
Circuit 72:
RC low pass 1.5 kHz
Setup information
Install the transistor and the electrolytic capacitor as shown in
Fig. 2.72.
Last but not least, connect the
Piezo element. Check the placement on the board again.
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 100
Ω
resistor,
1 x 1 μF electrolytic capaci-
tor, 1 x Piezo element,
1 x breadboard
Fig. 2.72:
RC low pass 1.5 kHz
Experiment
We will use electrical filter circuits, among other things, to suppress the noise. The basic circuit that serves
this purpose is a RC or LC filter consisting of a resistor/inductor and a capacitor. Depending on the wiring,
this creates a low pass or a high pass. In our case, we are using an RC low pass filter. The cutoff frequency,
up to which signals can pass, is 1.5 kHz. If you connect an mp3 player to the input, you will hear how dull
the playback sounds at such a bandwidth.
The circuit diagram for this experiment is shown in Chap. 3, Fig. 3.72.
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...
