In general, an IR remote control jammer is a device that produces non-visual (infrared) light "noise" of specific frequency,
in order to confuse IR receivers, and thus disable (jam) their remote controls. An IR R-C jammer does not harm any of the devices. You can imagine an IR jammer as a loudspeaker near you (the IR transmitter) and a friend of yours (IR receiver) that is some 10 meters away. If the loudspeaker is loud enough, then your friend will not understand what you are saying.
Alan's IR R-C jammer does exactly this. It has 4 powerful IR LEDs that are driven with pulses of specific frequency. One excellent feature of this Kit, is that it does not transmit one single frequency. That is because, there are several standardized IR transmitting carrier frequencies, and you can never be sure which frequency your remote control sends. In general, IR remote controls may transmit with 30kHz, 33kHz, 36kHz, 38kHz, 40kHz and 56kHz carrier wave frequency. To avoid conflicts and increase reliability, many remote controls may transmit with more than one frequency, making them more difficult to jam. So, Alan made this kit based on a PIC microcontroller (PIC 12F675), and programmed it to pulse the IR LEDs with all the above frequencies, one after the other. So, first, it sends 145 pulses with 30KHz frequency and pauses for 1mSec, then it sends 145 pulses with 33KHz frequency and pauses for 1mSec and so on. This way, no IR remote control can remain undisturbed from this jammer.
What i received is...
This is what i received from Alan: (as always, click on the pictures to enlarge)
A thick carton box with aeroplast protection inside keeps the kit safe during shipping
The kit was inside an anti-static bag. Remember that PICs hate ESD
These are what i found in the bag
One of the first things that i examine in electronics, is the PCB. I really like seeing quality PCBs with good artwork and nicely aligned solder mask. I hate thin PCBs whenever it is not required. Also, i like to see dense PCBs, with not unoccupied regions, unless of-course this is required due to high-frequency signals or high amps/voltages. The PCB that this kit has is good quality thick (1.6mm) pre-drilled with green solder mask and white silkscreen with the parts arrangement. The dimensions are 46 x 25mm. The rounded corners give a more professional look. I was (happily) surprised to find out that there are extra holes for the battery wires, to go through and release the mechanical stress at the soldering point. This is a feature that i will certainly copy in my future PCB designs! The fact that there are no mounting holes on a PCB always annoys me. This PCB though is planned to be mounted with double-sided adhesive foam tape directly onto the battery box, so it needs of no mounting holes whatsoever. In any case i like seeing mounting holes.
The top side of the PCB
The bottom side of the PCB
Mounting the kit
To mount the kit i used a temperature-controlled soldering iron, pliers and wire cutter. I followed the instructions line by line and measured the time needed to solder all the parts on the PCB. It took me about half an hour to finish.
The PCB with all parts soldered
The bottom side of the PCB
This is the kit with the battery box
Despite the fact that the PCB is double-sided, the soldering job was very easy. I used a temperature-controlled soldering iron, but a simple 20-22 watts soldering iron will do just fine. The pads of the parts are not too big to "consume" a lot of solder, and the holes have the correct diameter for each part. The solder flows with ease from layer to layer making the soldering job a piece of cake.
Instead of a simple 9 Volts battery clip, the kit came with a 9V battery box. The box has inside the battery clip and it has also a slot for a small sliding switch. The PCB is fixed on this battery box with 2 pieces of double side adhesive foam stickers, which are included in the kit. This is the part that i did not like that much for several reasons. I would prefer a small project box to fit the battery and the PCB inside, rather than this battery box.
Respect to creativity
I decided to write a separated paragraph for this feature. This is the first time that i see a kit with future expansion ports! If you see the circuit
schematic, you will see that there are 2 ports of the PIC not used, GP0 and GP3. Usually, in such occasions, these pins are left completely unconnected, something that i hate. In my designs, when i have unconnected pins, i usually put solder pads, so that if i need to use them one day (for some reason), i can easily solder a wire or a pin. In this kit, there are 2 pads, TP1 and TP2 just for this reason. They do nothing more than providing a way to use these unused PIC pins however you like. In addition, there are also pads TP3 and TP4 from which you can provide 5V regulated power!
This costs absolutely nothing to the one who designed the kit, but it proves that he or she respects the creativity of the end user.
Does it work?
Absolutely! I tested the kit with several different TV sets, with 3 different DVD players and with a CD player with amplifier. The kit blocked all the above mentioned devices with success. Also, i have to mention that it is very powerful. It can block the signal even when the remote control is much closer to the receiver than the kit itself. Another think that i liked is that the kit comes with 3 different resistor sets: One for high power, one for medium and one for low power. I used the medium power set, and it is enough to block the remote controls in a medium room (about 30 mt2).
I measured the current consumption of the kit when it operates, and it is about 92 mA, which is normal considering that there are 2 sets of LEDs with a 220 ohm resistor each set. One thing that i did not like at all, is the power consumption when the kit is not working. It draws about 0.6 mAmps or more. I am sure that the circuit can be tweaked to draw less than 20 micros when not used, and that would radically extend the battery lifespan (0.6mAmps = 600 micros).
The oscilloscope is always the hardest test to pass
What the oscilloscope says...
One more last test, maybe the hardest: The oscilloscope will reveal if the kit does what it promises, if all 6 frequencies are transmitted by the LEDs. It was not very easy to separate them, but finally i managed to see all of the 6 frequencies:
So, yes, it does what it promises.
The resultsDoes it really worth its weight?
The current price of the Kit (28 March 2011) which you can get from here is almost $19. Considering the PCB and the battery box, the kit is not overpriced at all. If you prefer doing it yourself from a scratch, Alan provides everything you need, the circuit schematic, the PCB layers and the PIC code as well (code and hex file). But if you do not have a way to manufacture a PCB and program a PIC, but you do want a TV remote control jammer, then this kit is a fair deal.
What i did like
Nice durable shipping package with anti-static bags
10/10 for the two future expansion pins
The holes for the battery wires is a brilliant idea
Nice very dense and quality PCB
I like the 3 different power set-ups and the 6 different frequencies
The designer did not think "cheap" when adding IR LEDs!
What i did NOT like
I was happy to see a box when i opened the kit, and disappointed when i found out that it was just a battery box. I would prefer a small project box instead.
The final project is completely unprotected from accidentally static discharge. Mounting the PCB onto the battery box is not a good idea
There are no mounting holes on the PCB, and absolutely no space to make one just in case.
A sliding switch to fit in the battery box should be included
The kit draws too much current when not used. It could be reduced by 30 times with a little tweak
No hard-copy of the instructions received with the kit. After getting in contact with Alan, he said that this way they are able to reduce the shipping cost and also the overall cost of the kit.
@jim cook this sounds as a nasty prank.... for that long time, it must be big with batteries or it must be connected to the plugs of your house. turn off the power of your house one night before go to sleep.
Someone has broken in my home and have placed noise generators that are so loud it almost makes my ears bleed. I can get up to leave a room and the noise follows me from one room to the next. I can't afford for someone to sweep my house electronically. Can you please help me. This is not a joke! I am desperate. They wait till I just about asleep, then it will wake you up, right out of bed! I have to go outside to get some relieve. This has been going on for about 7 or 8 months. If I had a jammer or something to counteract this outrageous noise. This is pure torture. It's remote controlled because if someone comes over to hear the noise, quiet as a mouse. Sincerely, Jim Cook
@Fung The KIT with the PIC you mean? It can be changed by software, according to the oscillator that you use. Is you have for example 4MHz, it can go roughly to 250KHz. But that is not the actual top limit, but what for?
I mean that I cannot buy the parts from the store of "alan-parekh.ca" because it is limits using USD or CAD (I think), and I found that the prices are quite high, especially the resistors, around HKD$1.1 each (over 11 times than that I buy in HK).
For those old IR LEDs, I have taken a current test before use. Observing with a digital camera, the output of them is quite high when 30mA current is applied.
So I thought that the voltage provided by the 9V battery is too low (only 7.9V), but it was not get flat yet...
Also, the IR LED used in the circuit "long distance IR detector" also have around 15 years history, water clear in appearance, now it still performs well, okay to work over 9m.
And, the rised question is: what is the maximum frequency of this kit can work out?
This is a piece of cake to buy IR LEDs in Hong Kong, just go to Shum Shui Po in Kowloon, with reasonable prices. Just HKD$0.1 (USD$0.0129) for each resistor!
Also, I have no a PayPal account yet, but a credit card instead.
The IR LEDs I have used are from an old remote control, the receiver of the original unit able to receive signals even the distance exceeds 5m. Those IR LEDs are deep green in color of the shell, wide beam, I wonder that they have became less powerful because they had over 25 years "history"...
For the link of site you provided, I have seen, they looked great but I do not think that I can buy them because I live in Hong Kong, China, neither HKD or RMB can be used for payments in that site.
Also, what is the range of frequency can this kit tune to?
After understanding about logic gates, the next stage of my learning of electronics is PIC, so I will find where I can buy PIC12F675 and try it.
The different LEDs are different indeed, the "dark" ones are narrow beam IR LEDs, and the others are wide beam IR LEDs. You can get a PIC12F675 and get someone to program it for you. Alan offers the hex file freely.
The problem with the jammer you have, is that the LEDs do not have enough intensity to block the signal. You may want to use more powerful LEDs with more voltage. Alan kindly offered me some quality powerful LEDs for test, but i have not test them yet. But if you see the specs (follow the link bellow), they are very-very powerful. You can get them from his store:
But I think that I cannot try out this circuit because it is based on PIC12F675, so sad...
It is found that the most left and right IR LEDs look different from that 2 at the center, is there a difference of the power output?
Also, my question rised up in here, after I made a jammer which references to this page: "http://pcbheaven.com/circuitpages/TV_Remote_Control_Jammer/", I found that the jammer was failed to "jam" the IR receiver of the HD TV, nowhere I tune the frequency, it still be able to receive signals from the remote control. Do you know why?