TV Remote Control Jammer - 555 Timer

This circuit is a TV remote control jammer. It is a very simple circuit by design, and it will not cost you too much money to make this. This circuit will mess with the infra-red receiver on a TV and block a channel change sent by the remote. It does this by producing a constant signal that will interfere with the remotes signal, which results in the remotes command not being received by the IR receiver. This specific TV Jammer produces signals of 38 kHz, which should work for most modern Televisions. Almost anyone can make this circuit, and I would recommend this circuit as one to make for someone new to electronics, who wants to have fun with their creation.

• Resistors of Values: 1k, 2*470, 5.6
• Polarimeter of Value: 10k
• Capacitor: 10nF (Digikey)
• Diodes: 1n4148 (2) Datasheet
• LED IR (Datasheet for IR LED I used)
• Transistor: 2n3904 (Datasheet)
• Breadboard (Digikey)
• 9 Volt power source

This circuit runs as a 555 Timer in the Astable Circuit mode. An astable circuit runs by causing the output voltage to constantly change between Vcc (Positive Supply Voltage) and 0 Volts.

In this circuit, the capacitor initially has 0 Volts across it. This also means that the threshold pin and the trigger pin on the 555 timer are also zero. This means that the output on the 555 timer will be high. As a result, this voltage will start to increase slowly until the capacitor is at two thirds of the Vcc (2/3*9 volts). Once it has reached a voltage that is two thirds of the Vcc, then the comparator attached to threshold inside the 555 timer will flip, and the output will now be low. This means that the capacitor will start to discharge, and it will do so until it reaches a voltage of one third of the Vcc (1/3*9). Then the same process as earlier will repeat (except it will start at 1/3*Vcc now instead of 0 Volts.) It is this constant process being repeated that causes a frequency in the circuit. Now, this constant change also affects the transistor that causes the IR LED to light up. When the output is low from the capacitor, the IR LED is off, and when it is high, the IR LED is on.

Above are two graphs to help you understand this concept better (the green line is what we are looking at). The first is the capacitor at the frequency where it blocks the TV IR receiver. The second is at a much lower frequency, allowing the constant charging up and discharging to be seen more clearly.

In order to actually change the frequency in the circuit, you need to mess around with the potentiometer. The potentiometer is actually what affects how fast the capacitor is able to charge up, and then discharge. In order to achieve a very high frequency (such as 38 kHz), you need to have the resistance in the potentiometer very low (if you look at the above circuit diagram, you want #1 on the potentiometer to be as low as possible).

So a normal television remote works by sending out a series of pulses (at a specific frequency) that are filled with information each time that you press a button. The receiver in the TV then decodes this information when it receives it, and does whatever action is programmed for the button that you've pressed. The television remote control jammer works by sending out constant pulses that are at the same frequency of the remotes (normally 38 kHz), just without any information. This then causes the receiver to act as if nothing happens if you try to use the remote while the jammer is on. This is because it instead receives the signals that hold no information in them.

Above is a schematic of the design, with another picture of the TV Remote Control Jammer made on a breadboard. These are to try and help you understand what it might look like when you've successfully made this circuit.

For me, there were quite a few problems with the circuit above. The original design did not have the 470 resistor between the IR LED and the power supply, which resulted in every LED burning out. I would recommend changing this and testing to see which value specifically gave you the best results. Additionally, you can also use different IR LEDs from the one that I used above, as there are so many options available (use what works best for you and your budget.)

I would recommend that those who struggle with cable management on their circuits really pay attention when making this. Depending on the size of your breadboard it is extremely easy to connect the wrong parts together.

This circuit could be very easily expanded upon in a simple way. You could add a switch that would turn the circuit on and off in order to use it much more easily in a business application. I would likely do this and then add housing to the circuit in order to make it much more difficult to damage (you're using a TV Remote Jammer, someone is going to get mad). Additionally, you could expand upon this design to make it so that it can produce a stronger signal. This would also allow the blocker to be placed farther away form the television, and would make it more practical for actual use.

This circuit would be quite useful for business owners who deal with the public quite often. For example, take someone who owns a bar. There might be someone in the crowd who decides to bring universal remotes to either mess with the owner, or to put what they want on the TV. All the owner needs to do is plug in this circuit and they no longer need to worry. The downside of this circuit is that it needs to be quite close to the TV in order to work, but it still is quite useful.