555 Timer TV Remote Jammer

How does the TV jammer work?

A television remote remote uses light to carry signals from the remote to the television. The Led on the remote emits invisible infrared light that correspond specific binary codes.These binary codes contain commands like power on, volume up, or channel change.For example when we try to turn on the TV it emits a signal containing binary codes which command the Television to turn on.This information is received by the television in which it decodes the incoming infrared pulses of light into binary code that the internal microprocessor processes. Once the signal is decoded, the microprocessor executes the commands.The TV signal jammer emits IR pulses and confuses the infrared receiver in a TV. It produces a constant signal that interferes with the remote control signal.

• 9V Battery
• Ne555 Timer
• 29304 transistor
• 2 ( 1n4148 diodes)
• IR LED
• 10 n capacitor
• Resistors, 10k,1k,470
• Breadboard

I used LTspice to simulate my circuit for this project. The first circuit is the circuit I used to construct the Signal Jammer. From the simulation it showed the voltage passing through the LED was about 0.5V, which is really less because about 1.4 V is required for the LED to work. For that first circuit the current running through the LED was about 650mA.

To make the current going trough the LED less I added a 5.6 omh resistor after the emitter of the transistor. This gave a result of of about 98mA current going through the LED. However it did not make a big different in the voltage across the LED.

The frequency emitted for both the circuits were about 14 kHz. I calculated it by finding the time difference in the graph and then used the formula f= 1/T(f is the frequency and T is the time period). However the frequency required to interrupt a TV remote signal is about 30-40kHz.

Things to remember:

• The threshold pin and the trigger pin should be connected to each other.
• The 10 n capacitor should be connected between the trigger pin and the ground pin.That wire then should be connected to ground
• The 1k resistor and the 470 ohm resistor should be connected in series coming out of the Out pin and should be connected to the base of the transistor.
• The two 1n4148 diodes are also connected in series.
• The negative end of the LED is connected to the emitter of the transistor.