130
2.46 Whistle buoy
Circuit 105:
Whistle buoy
Setup information
Install the two transistors, the five resistors, the ceramic capacitor and the electrolytic capacitor as shown in
Fig. 2.105.
The ten jumper wires come next. Finally, insert one end of the jumper wire, which will function
as switch (shown dashed) and is labelled with
Start
. 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 2N3906 transistor,
1 x 10
Ω
resistor, 2 x 10 k
Ω
resistors, 1 x 47 k
Ω
resis-
tor, 1 x 100 k
Ω
resistor,
1 x 10 nF ceramic capaci-
tor, 10 x 1000 μF electro-
lytic capacitor, 10 x Piezo
element, 1 x breadboard,
1 x 9V battery with clip
connector
Fig. 2.105:
Whistle buoy
Experiment
A whistle buoy is used to produce a loud and prominent warning signal. Our circuit is at least capable of
accomplishing the second point. Close the
Start
switch. You do this by inserting the end of the wire jumper.
The generator howls. Open the switch again, by pulling out the appropriate wire end. The whistle buoy
slowly reduces its frequency. Repeat this play as often as you like.
The circuit diagram for this experiment is shown in Chap. 3, Fig. 3.105.
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...
