Velleman EDU02 - Manual (Page 21)

21 www.vellemanprojects.com
Required parts: Solar cell, piezo sounder, IR remote control (option).
How it works: Solar cells are
sensitive to infrared light. When hit
by infrared light, they generate a
voltage, like they do with sunlight. IR
remote controls generate a beam of
infrared light when they are operated.
This beam of light is turned on and
off very fast by the internal
electronics of the remote control.
The pattern generated by the on-off
transitions is different for each button
of the remote. This allows the
receiver to recognise each individual
button. In this circuit, the on-off
transistions are translated into sound
by the piezo sounder.
More fun:
Try ‘listening’ to different light sources such as
led lighting, fluorescent lighting, etc...
SOLAR CELL
+
BUZ1
PIEZO