We’ve already seen how to jam mobile signals with a simple mobile jammer circuit in previous postings. Now, in this project, we’ll learn about another intriguing concept: the TV Remote Jammer Circuit, which is a simple and practical circuit based on the NE555 Timer IC.
Outline
- Introduction
- TV Remote Control Jammer Principle
- Features of RC5 protocol
- TV Remote Control Jammer Circuit Diagram
- TV Remote Jammer Design
- TV Remote Jammer – Circuit Simulation Video
- How to Operate this TV Remote Jammer Circuit?
- TV Remote Jammer Advantages
- Limitations of the Circuit
Introduction
The TV jammer circuit in this project disrupts the functioning of a TV’s infrared receiver by emitting a constant signal that interferes with the remote control’s signals. When the circuit is activated, the TV becomes unresponsive to any remote commands, ensuring that you can enjoy your program without the fear of others changing channels or adjusting the volume.
TV remote controls primarily employ infrared light technology. While this type of light is invisible to the human eye, it can be observed using a camera.
TV Remote Control Jammer Circuit Principle
The concept behind the TV remote control jammer is to emit a continuous infrared (IR) pulse at the transmitter’s carrier frequency. This action causes the receiver to receive an unrecognized signal, resulting in no responsive actions being taken.
When you press a button on the TV remote, it emits a series of IR pulses. The IR transmitter is permanently affixed to the surface of the TV remote, and it emits pulses in distinct patterns for each button.
The IR receiver, which is positioned on the TV, receives the sequence of pulses sent by the TV remote and deciphers which button has been pressed.
Typically, Philips TV remotes adhere to the RC5 (Remote Control) protocol. This protocol was developed by Philips in the late 1980s. According to this protocol, the remote transmits 14 bits for each button press. The diagram below illustrates the frame format of the RC5 protocol.
The initial two pulses both correspond to logic 1 start bits.
The third bit in the sequence serves as the toggle bit. It switches state when a button is either pressed or released, allowing us to discern the button’s activation.
The subsequent 5 bits represent the device address. Bit 4 stands as the most significant bit (MSB) of the device address, while bit 8 signifies the least significant bit (LSB) of the device address.
The remaining six bits in the frame format are allocated for the command bits. Each button on the IR remote possesses its unique set of command bits, enabling us to identify which button on the remote has been pressed.
Features of RC5 protocol
- Bi-phase coding (Manchester coding)
- 36Khz or 38Khz carrier frequency
- Constant bit time of 1.778 ms
- 5 bit address and 6 bit command length
Modulation: The RC5 protocol uses bi – phase modulation. All 14 bits are equal length of 1.778ms.
TV Remote Control Jammer Circuit Diagram
Circuit Components
- NE555 timer
- 1N4148 diodes – 2
- Resistors – 470 Ω, 1KΩ, 5R6 (5.6Ω)
- POT – 10KΩ
- 9V Battery
- Ceramic capacitor – 10nF
- Transistor – NPN (BC547)
- IR – LED
TV Remote Jammer Circuit Design
The purpose of this circuit is to produce a signal operating at a frequency of 38 kHz. The central element of the circuit is the 555 Timer, which is currently configured in an astable multivibrator mode. In this configuration, the 2nd and 6th pins are connected together to enable triggering at the end of each timing cycle, and both of these pins are connected to ground through the capacitor. Additionally, the fourth pin of the 555 timer is linked to the power supply to prevent any unintended resets.
10KΩ pot is used to adjust the frequency of 555 timer. The current through the IR-LED is limited to 100mA because of two 1N4148 diodes, as these form constant current arrangement when combined with transistor and resistor.
TV Remote Jammer – Circuit Simulation Video
How to Operate this TV Remote Control Jammer Circuit?
- Connect 9V battery to the circuit.
- Now adjust the pot 10KΩ to produce 38 KHz signal.
- Now press the TV remote buttons.
- You can observe that TV will not receive any commands from remote
- Disconnect the battery from circuit and press TV remote buttons.
- Now you can observe that TV will receive the commands from Remote
TV Remote Control Jammer Circuit Advantages
- We can use this circuit to jam the remote signals so that the other people cannot change the channel while watching our favorite program on TV.
- It will not affect the signal receiving capacity of the TV.
Limitations of the Circuit
- The circuit should be tuned correctly to 38 KHz frequency to get accurate results.
