28-03-2012, 02:58 PM
INFRARED BUG
ir bug.pdf (Size: 118.25 KB / Downloads: 55)
This circuit can be used to detect
the presence of modulated
infrared signals in its vicinity
from any electronic source, for instance,
an IR handheld remote controller.
It can also be used for testing IR
burglar alarm systems.
Fig. 1 shows the circuit of the infrared
bug. Besides the power supply
(one 9V PP3/6F22 compact battery
pack), it consists of an infrared
signal detector-cum-preamplifier
followed by a melody generator
and a tiny audio amplifier. The cir-