214
2.89 Active probe
Circuit 189:
Simple active probe with Piezo element
Setup information
Install the transistor, the three resistors, the ceramic capacitor and the three electrolytic capacitors
Fig. 2.189
followed by six jumper wires. 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 J111 FET transistor,
1 x 2.2 k
Ω
resistor,
1 x 4.7 k
Ω
resistor, 1 x 1 M
Ω
resistor, 1 x 10 nF ceramic
capacitor, 1 x 10 μF elec-
trolytic capacitor, 1 x Piezo
element, 1 x breadboard,
1 x 9V battery with clip
connector
Fig. 2.189:
Simple active probe
with Piezo element
Experiment
The active probe operates within a frequency range from 100 Hz to approximately 1 MHz. If our circuit is
used within the NF range, you will hear the signal coming from the Piezo element.
The circuit diagram for this experiment is shown in Chap. 3, Fig. 3.189.
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...
