Electronic Drum - Maker Factory ELECTRONICS EXPERIMENTS BOX Manual

2.59 Electronic drum.

Circuit 127: Electronic drum
Setup information
Install the three transistors, the three, transistors, the eleven resistors, the four ceramic capacitors and the
two electrolytic capacitors as shown in Fig. 2.127. The 20 jumper wires come next followed by the jumper,
which will function as a switch (shown dashed). For your guidance, we labelled the "switch" with Drum.
Last but not least, connect the Piezo element. Check the placement on the board again and only then con-
nect 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
Experiment
Even if everything is wired correctly, nothing will happen at first. But when you activate the drum button
briefly, you will hear a beat coming from the Piezo element – although unfortunately, a bit low. Volume and
frequency range are reasonable if an audio amplifier is connected to the output of our circuit. But only if
you are familiar with the relevant safety guidelines on working with devices that are to be connected to the
mains as per VDE and know how to observe them should you connect the audio amplifier to the circuit.
The circuit diagram for this experiment is shown in Chap. 3, Fig. 3.127.
152
Components required:
2 x 2N3904 transistors,
1 x 2N3906 transistor,
1 x 220 Ω resistor, 1 x 1 kΩ
resistor, 1 x 10 kΩ resistor,
1 x 22 kΩ resistor, 1 x 47 kΩ
resistor, 2 x 100 kΩ resis-
tors, 3 x 220 kΩ resistors,
1 x 1 MΩ resistor, 3 x 10 nF
ceramic capacitors,
1 x 100 nF ceramic capacitor,
2 x 10 μF electrolytic capaci-
tors, 1 x Piezo element,
1 x breadboard, 1 x 9V bat-
tery with clip connector
Fig. 2.127: Electronic drum