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Discussion Starter · #1 ·
Brag:


When we built our house ten years ago, I located the guts of our computer network, security system, intercoms, phones, and entertainment in a closet off the study. My wife calls it "World Central." We use IR receivers in the study, the living room, the kitchen, and in three bedrooms, to control devices in WC. You can select different audio and video for TV sets and speakers in all those rooms plus two bathrooms, the patio, and the garage.


Complaint:


This setup has worked well--except that I have to replace IR emitters again and again. I can't be sure the IR relays or "blocks" haven't deteriorated, although they seem to work as well as ever. We have four DirecTV DVR receivers. On average, we have to replace one every year, because they stop responding to IR, even when you flash their native remotes directly into their "eyes." But it's the IR emitters that cause most of our remote control failures. At least, replacing them corrects most problems when nothing else works. I buy the things by the dozen, mostly cheap snake heads, with a few fancier types thrown into the mix. "Blasters" don't last any longer than the cheapies.


We keep World Central cool with a large, slow fan. Even so, the adhesive attaching the emitters to our equipment eventually goes gooey. So do other adhesives and Gorilla Tape. And neither the emitters nor the lenses of our equipment's IR receivers stay pristine. Sometimes, cleaning them helps. When it doesn't, new emitters restore control--for one to three years--before I have to replace them again.


I can't be the only person with this problem, but now that I've started looking for a better solution, I don't find it mentioned. Have I been penny-wise and pound-foolish? Do I just need to spring for more expensive emitters? Better yet, could I get freestanding blasters powerful enough to flood the inside of WC with just a few, obviating the need to attach 17 separate emitters?


Thanks.


Bryan
 

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Hi Bryan


I have found Xantech emitters/connecting blocks to be virtually bulletproof, with many units 10+ years old still going strong. I think I've replaced two (out of hundreds) in that time which simply 'went bad'.


As far as the adhesive goes, I've used a hot glue gun to attach them for a long time, and that solves the problem with the gooey adhesive (especially with DTV receivers). Super Glue also works.
If you really want to clean things up, and feel confident enough to do it, placing the emitter inside the equipment by the ir receiver is another solution.


HTH

jc
 

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Discussion Starter · #3 ·
Thank you, John. I will heed your advice. I have a glue gun but had not yet tried attaching emitters with it. Now I willthat is, if I continue to use separate emitters for every component we operate with universal remotes.


I am using two Xantech connecting blocks (I should not have characterized them as relays)one since 2001 and one since 2006. Like you, I have found they hold up.


Many, maybe most, of the first emitters I installed were from Xantech too. I suspect their demise was my own fault somehow. Just wish I could think how. Any speculation as to what caused those two of yours to fail? Ever heard of other people with emitter failures as persistent as mine? Do you agree that the prospect of continual and frequent emitter replacement would discourage most installers of whole-house systems?


The sheer number of devices I have attached IR emitters to, plus the ten-year service life of this otherwise-satisfactory system, create a lot of opportunity for components of all sorts to fail, don't they?


I did not itemize all the pieces of equipment I have had to replace. Statistically, my complaint may not be justified, yet the emitters stand out. For every other piece that has had to be replaced, I think I have replaced five emitters.


Before I order another batch of Xantech'sor anyone else'semitters, I think I'll wait to see whether I hear other recommendations.


Bryan
 

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Check also the temperature of the various pieces of equipment. Most manufacturers don't design their cooling/temperture immunity expecting a World Closet of concentrated equipment.


LEDs really only fail due to excessive temperature, either through inadequate cooling or overdriving them with current. Perhaps your emitters are being driven with a high duty cycle? Recall that most IR signals are modulated at, say, 38KHz, and the modulation is aranged so that the individual on flashes are about one third the total width, i.e., about 9 microseconds of on and 15uSec of off. Additionally, most IR signals have relatively short periods of modulated output and longer periods of no output. For example, the NEC protocol, used in more equipment than any other, leaves the emitter off for two thirds of the time during a transmision. A 0 bit is transmitted as 0.5milliseconds of modulated output, followed by 0.5mSec of no output. A 1 bit is 0.5mSec of on and 1.5mSec of no output.


Look to air temperature, equipment temperature, duty cycle, and perhaps constant transmission of a signal which isn't recognized by any of your equipment.
 

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Discussion Starter · #7 ·
A thermometer I just put in “World Central” read 78°F, 3FingeredGlove. On hot summer days, temperatures in the closet may hit 80. Although electronics prefer cooler temps, I have never been uncomfortable working inside. On the other hand, gooey emitter adhesive may be a sign you’re onto something.


I have kicked myself for not venting our HVAC directly into—as I did into four walk-in closets—replete, ideally with intake ducts as well as exhaust ducts. WC is adjacent to a huge bay above a fireplace, and the bay serves as a platform for a plasma TV set for the study. Its exhaust fan pumps air out into the space behind the plasma set, cooling it along with the closet.


(Hmm. I water-cooled a PC I built, only to decommission it after it became possible to build more capable computers cooled by air. I still have seven cooling blocks and a radiator with pumps.)


The fireplace is redundantly insulated and does not contribute to extra heat in the closet—certainly not before Thanksgiving or after Easter. And the plasma TV in the study does not cause remote control problems. The IR receiver in that room is specially designed to resist interference from plasma sets.


The pieces of equipment that have failed have been the four DirecTV DVRs, the emitters, and one FM modulator. Compare that with the following list of equipment that continues to work fine after ten years:


An Elan whole-house entertainment-intercom system, two high-wattage receivers, two DVDs, a MiniDisc deck, a VCR, four APC uninterruptible power supplies, three four-channel Channel-Plus RF modulators, a Channel-Plus RF distribution block, two Xantech IR connector blocks, a DSL modem plus wired and wireless switches, a receiver for security system panic buttons, and a few miscellaneous pieces of gear.


The survival of this equipment may speak to the durability of contemporary electronics rather than to the suitability of temperatures in the closet. Even if the temperature I just read doesn’t strike me as particularly warm, some zones do get warm indeed—just above the receivers, for instance. Both receivers sit high in the closet, smack in the main flow of a 32-inch cooling fan. The emitters, on the other hand, are all over. I must admit a few get fairly warm.


Given the scanty evidence pointing to temperature as the culprit, however, I hope some industrial-strength versions of blasters would eliminate the need for so many attached emitters. I have a couple of large IR emitters labeled “blasters.” They are not effective throughout the closet, but are more powerful ones available? Is such a solution even feasible? Or should I just keep buying cheap emitters and replacing them as they go bad?
 

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Discussion Starter · #9 ·
The emitters that stopped controlling devices still illuminate. Maybe excessive temperature has affected the latencies of their illumination. Are you suggesting heat can spoil their "rhythm," the timing of pulses?


If so, I guess I'm back to the possibility heat's causing the trouble, right? Same vulnerability and same limited solutions, right?
 

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Discussion Starter · #10 ·
Petew, constant transmission of signal? Not sure what you mean. Is there some way to tell whether the signal transmission of the emitters is constant enough? What are we looking for? How long should I see the emitters light up?


With a little X10 camera I use to read dials in WC, I see them flicker. Their flickers look pretty much like what you see from remotes, just dimmer.


I think we can rule out any wholesale disruption. Every time I flash a remote, the TV picture from the X10 camera flickers—every time. Their exact rhythm or coding might be off by milliseconds.
 

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Bryan,

I wouldn't expect heat to have any effect on the timing of IR signals from an emitter. I'm not sure what you mean (in your reply to Petew) by flickering. The emitters should either be flashing brightly, at the moment an IR signal is being sent and perfectly black the rest of the time. If there is a low level of IR coming from the emitter most of the time, that can not only tend to overheat the LED, but also the low level signal can confuse the receiver, just as the IR emission from plasma TVs affect IR reception and decoding.
 

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Discussion Starter · #12 ·
Thanks 3—and thanks to johnscousin and Petew too—for your helpful tips. I’ll definitely put them to use. I hope it’s not too ungrateful of me to look your gift horses in their mouths, but see, I’ve still got an itch. If you guys tell me you doubt any possibilities remain, your opinions will be good enough for me.


Right now, though, I still have that hunch about “blasters.” I hope one of you or somebody else on the forum knows something about them. I only know the term “IR blaster” from sites that sell them—and from ending up with a couple of them that came with equipment I’ve bought. My impression is that they’re just more powerful IR lamps and may be capable of flooding an area like “World Central” with enough wattage to reach the IR receiver lenses built into each and every device we control with infra red remote controls. It might take several of the things to ensure full coverage, but I hope I could dispense with 17 separate snakehead emitters attached to each piece directly over their lenses.


My uninformed guess is that our small emitters aren’t bright enough to cut through the adhesive that comes on them, especially after the adhesive gets soft and thick and starts to refract their emissions—or opaque enough to block them. My thinking may be wrong. I don’t know why these emitters stop working, it looks like we have an optical problem. I think it’s telling that, often, I can obviate the outright replacement of an emitter by scrubbing it and the lens of the device it controls with a solvent. After milder solvents have failed, I’ve resorted to cleaning some plastic lenses with acetone. That may have “frosted” them a little. I don’t think you’d immediately detect unmistakable glazing or clouding, but a few do look suspect. It’s hard to rule out adhesive residue.
 

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This is a great thread, lots of good tips here.


My 2 cents. If the emitters appear to stay lit there may be interference affecting them even when they are not sending signals. I have seen IR overload often affect Cable and DTV boxes and there are two solutions we often recommend.

1) Place a small piece of black electrical tape between the emitter and the equipment with a pin hole for the signal to go though. You may even see the devices respond better but this may not work with all gear.

2) Use IR Emitter covers. Xantach maked nice ones for their Designer Series Emitters and they are included with my favorite emitter, the RTI Virsa Mouse. These are not just cosmetic. They help prevent interference from other devices in the closet and limit the Ir communication to what comes through the cable.


Jim
 
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