TV Remote
Just point this small device at the TV and the remote gets jammed .
The circuit is self explanatory . 555 is wired as an astable
multivibrator for a frequency of nearly 38 kHz. This is the frequency
at which most of the modern TVs receive the IR beam . The
transistor acts as a current source supplying roughly 25mA to the
infra red LEDs. To increase the range of the circuit simply decrease
the value of the 180 ohm resistor to not less than 100 ohm.
It is required to adjust the 10K potentiometer while pointing the
device at your TV to block the IR rays from the remote. This can
be done by trial and error until the remote no longer responds.
The estimated cost of the whole circuit including IR LEDS and
battery is not more than Rs. 40/-