Instructions

47
Game and Knowledge in Electronics-Lab
Valuable items in a museum and in a safe
of a bank are secured with laser beams. As
soon as a burglar interrupts a light beam,
the alarm is triggered. You can build such
an alarm for yourself. The light comes from
46
PROG
Laser alarm
Build a U-shaped scaffolding using the
mounting plates so that the tricolour LED and
the light sensor are directly opposite each
other. The room needs to be very dark so
that the surrounding light does not confuse
the light sensor. Only the LED light should
be on. If you hold your hand between the
light source and the sensor, the alarm siren
will sound. The alarm system is now armed.
You can place something valuable or sweets
inside the U. If a thief tries to grab them, the
alarm will scare him off.
the tricolour LED and is detected by the
light sensor. You also need to connect the
loudspeaker. The programme is started with
the connection E - G .