I’ve got two spare LEDs. Bought the parts to build 3 of these things, knowing full well I’d mess one up somehow
I’ll probably do the kapton thing. The LED doesn’t dissipate that much power - it’s getting driven by 2.8A at about 1.3V, and the duty cycle’s only about 20% outputting codes. So less than a watt of dissipation.
Once I get this design tested/perfected, I might try and find a LED star capable of holding an Osram SFH4725S. More expensive but the IR output power is about the same, and it’s in a better package for flashlights than the 5 chinawatt DX special.
Action shot! The video looks purple because I’m using a camera with the IR filter yanked.
I decided to omit the kapton tape and just glue the IR emitter directly to the pill with Arctic Alumina. I used a thick layer and managed to keep the base isolated. I’m cleaning up the AVR code now to share it.
When TV codes are finished sending, the microcontroller powers down and current draw is about 250uA. You’re safe for a while if you leave it on.
The flashlight ‘chirps’ very quietly when it’s sending codes - if you hold it up to your ear and click the switch, you can tell whether you turned it on or off by listening for it. Or you can check it by looking at the light with a cellphone camera.
Passive IR motion detectors primarily see at much higher wavelengths, over 5µm (5000nm). Other wavelengths are cut out by a filter window but perhaps enough can still get through. Some datasheet show 0% below 4µm but I’ve also read a report of a high power IR 940nm illuminator reducing the sensitivity of a PIR detector.
Always worth a shot.
gmarsh, I like this (and not for anything malicious or illegal!)
Any thought given to selling a finished dropin for P60s? Or is there so much hand-assembly and fiddling that you couldn’t make it at a decent price point?
Or about 17 bucks. There wasn’t much work involved, probably 1/2 hour total, to finish the construction of one so I’ll say I’ll sell one for about 30 bucks. I ordered the bits to build 3 - I blew 1 led, I’ll keep 1 myself and I’ll sell one.
I’m now looking at a different LED (Osram SFH4725S) which is better than the 5W LED in pretty much every imaginable way except continuous current handling. If I actually make a “sell a few of these to people” product for people, I’ll go with that LED - just need to find a 16mm MCPCB for it.
I beg to differ on the psychological aspect, though. Turning off the TV is probably not the best way to calm down a bunch of drunken sports enthusiasts
Second P60 module built/tested/working. Not tested on an actual TV (yet…), but the IR LED’s flashing away as it should.
I’ve got a PM from someone who wants just the P60, I’d rather flog it with the WF-501B. Reason being I changed the spring from the stock Nanjg one to a different one so it would work with the stupid black “rivet insert” that’s in the 501. If the P60 faces a cell directly, the new spring could step sideways and touch something it shouldn’t, causing a shorted cell or damaged driver - the ‘rivet insert’ has a ridge that prevents this from happening. I’m also not the greatest fan of the 501, so this is a dumb attempt to get rid of it
Also got a PM from someone who wants a reprogrammed driver and nothing else. I’ve got a single spare one, I’ll PM you back.
After this, it’ll be a few weeks at least - I’m starting work on the Osram LED version. It’ll have at least 2x more optical output power, much better throw, and be much easier to build. I have to design/order PCBs and get LEDs, a couple new hosts to try, batteries, more drivers, etc. I’ll make a new thread when things are up and running again.
The project is working beyond expectations. Last night I turned off a front window TV in a cellphone store from 200-300ft away. I haven’t even put the aspheric lens on the light yet J)
Running the P60 by itself off a bench power supply at 4.2V, the pill gets warm but not hot - this is after banging out all 130 TV codes, which takes about a minute - the IR duty cycle seems sufficiently low that heat isn’t an issue. I burnt a finger attempting the same test on my XM-L P60, if that indicates anything.
I have 1 driver left that I can modify. I got a PM asking for it, responded and haven’t heard back yet. If I don’t get an answer, I’ll put it on the market for 15 bucks - if I end out banging these out in bulk, I’ll charge less. I put in a fasttech order last night for more drivers, blank P60s etc so I should be “back in business” in a few weeks.
I’ve also ordered Osram “Black Oslon” LEDs to experiment with. They’ve got a better viewing angle, 2x forward voltage (3.x volts), 2-3x more IR output power, and a smaller/better centered die that should allow better throw. Designing a PCB to hold it now, will be 0.8mm thick FR4 and 13.5mm diameter. Sadly nobody makes MCPCBs for Oslons.
