Do you guys use whatever flashers you have on hand or does interchanging them cause you problems?

Setting up a Navigator Harbor and Xantech emitters are all I have on hand.

Thanks!

=Tom

Interchanging as you speak of shouldn't be a problem, the only time i've ran into problems was when i tried to use 2 different type emitters in the same set up.

Mike

Niles used to use an oddball IR format, but they have bnow switched tothe same 12v format Speakercraft and Xantech uses.

I've had issues using the Philips emmitters that come with Pronto/RC5400 Base stations, but not any real issues with the others.

Impaqt,
the format of the system that puts out the signal is not really the question here. The screwiest part of the old Niles system, which actually did use 12 volts, was that the minus side of any LED was not common with the minus side of the other LEDs. Each LED minus had a resistor or a trasistor between it and ground. This meant that if you tried to use more than one grounded thing, like the IR control input on a McIntosh or Lexicon preamp, both of those controls would not work right.


The emitters themselves are all pretty much the same. That said, no two emitters are identical. Each one turns on when there is a particular voltage across it, will not turn on below that voltage, and will not change the voltage across it (except infinitesimally) if you raise the voltage you are feeding it. That is why a resistor is necessary no matter what. All LEDs of a particular manufacturing run tend to be pretty much identical, but as noted, mixing brands, particularly if you try to wire in parallel without added resistors, will give problems.

The basic setup is that a terminal block or whatever puts out a voltage that can flow at some current. A resistor for each emitter output, inside the block, both limits the current that flows through the emitter and guarantees that multiple emitters will work.

Multiple emitters might not work if they are in parallel, that is, all of the plus sides connected to plus and all of the minus sides connected to minus. Why? Because, as I said above, no two emitters are identical.

When you run a current through a resistor into an emitter, the emitter turns on when the voltage across it reaches some particular value. If you increase the voltage supplied to this combo of resistor and emitter, then the resistor drops more voltage and the current increases. The voltage across the emitter remains almost exactly the same.

Since no two emitters are identical, if you put an emitter that turns on at, say, 2.5 volts in parallel with one that turns on at 2.6 volts, the 2.6 volt one will never turn on. The other one will limit the voltage across both of them to 2.5 This is why multiple hard-wired emitters are a problem. If they all come from one manufacturing batch, they might work, but there is no guarantee.

The manufacturers use two methods to overcome this so that multiple LEDs can be used. First, a resistor in series with each emitter keeps the voltage across one emitter separate from the voltage across the others, so they will all work. Second, when two emitters are on one cable, they are in series. The voltage going into the resistor is high enough to turn on two LEDs in series without lowering the current too much, and the resistor isolates this series pair from all other single or doubles.

Xantech has Blink-IRs, emitters that give off visible and IR light. I believe that each of these is a pair of LEDs, one visible, and one IR, in series, so one of these acts like a pair of regular emitters. A dual Blink-IR is like four LEDs in series, which only the older Niles equipment ever recommended using, so those are likely to give problems when used with non-Xantech equipment.

What about multiple receivers?
i have put a system together with a xantech recievor at the front of the room and a axium panel mounted recievor at the rear wired in parelell. it appears to work perfectly but is there more to it??
Mark

I think if you use a block with outputs for 4, 6, 8 emitters they are each buffered outputs, right? This would make differences in emitters no problem if it's one per output or a dual on a single output.

Well, I'm about to find out tomorrow, I guess.