Infrared FAQ
The most Frequently Asked Questions about BE Infrared Products
* This page will continue to grow over time *
Table of Contents
- What kind of wire should I use for my IR system ?
- Why are the confirmation LEDs on when no IR signal is being sent?
- After installing my new flat panel TV my IR system doesn't work, what's wrong?
- How can I identify a noise source, find what is effecting my IR system?
- What power supply voltage is required by BE's IR system?
What kind of wire should I use for my IR system?
Use a low capacitance twisted pair communications type cable for IR control systems. A minimum of two twisted pairs are required. Most installers use CAT5 or CAT5e cable.
Using the wrong type of wire type and/or faulty wiring plans cause most IR system problems.
See infrared application note: IR Wiring Plan That's East to Modify and Troubleshoot.
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Why are the confirmation LEDs on when no IR signal is being sent?
Ambient Noise is triggering the IR repeater sending false signals through the IR system.
The confirmation LEDs tell us a signal, real or noise induced, is passing through the system. This is a great help setting up and troubleshooting IR systems.
Random noise can flash the confirmation LEDs once in a while in no set pattern.
Steady noise can flash the LEDs so often they look on all the time, our eyes are too slow to see them flash. The LEDs can look on but dimmer than their full brightness if the duty cycle (time they are really on) is less than 100%.
Even though a system can function perfectly with some noise present it is always best to place the IR repeaters in locations that avoid noise getting into the system.
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After installing my new flat panel TV my IR system doesn't work, what's wrong?
If all worked well before the new TV was installed the problem is most likely noise.
Flat panel plasma and LCD TVs can produce quite a bit of electrical noise, especially the large ones (>50"). This is due to high speed video circuits, LCD florescent back lighting, switching power supplies, large amounts of escaping heat (heat = infrared), and often inadequate shielding.
Flat panel TV noise can sometimes get into the IR system through an IR repeater's sensor. Repeaters being installed close to flat panel TVs should be tested at the desired mounting location before drilling holes in cabinets or cutting holes in drywall. A quick test can make an installers life easier by avoiding noise problems before they are built into the system.
Testing can be done by taping the repeater to a piece of wood or ladder in the desired location, just run the wire in the open on the floor, if the system is effected by the TV try different locations until you find one that works well (Hint: mounting below TV avoids rising heat waves).
For difficult locations you might have to buy a special Plasma or LCD proof repeater at a much higher cost and receive a much reduced IR remote control range (lowering in-band noise will also lower an in-band signals). In some cases this will be required, especially when using pre-existing mounting holes.
That said: We have hundreds of working plasma and LCD TV installations. Just like working with direct sunlight, placing repeaters in the right location will eliminate noise in most cases.
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How can I identify a noise source, find what is effecting my IR system?
Turn off one A/V component at a time. If the noise goes away you found the culprit.
If the noise remains turn the component back on and then turn off the next component. Continue this process of elimination until the noise source effecting the system is revealed.
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What power supply voltage is required by BE's IR system?
BE's IR system is designed to run on 10-14Vdc. The center pin is positive.
Many 9 -12Vdc supplies meet this requirement but a 12Vdc regulated supply is ideal..
The two types of power supplies being considered are unregulated and voltage regulated:
- Unregulated supplies are rated at full load capacity. A 9Vdc @500mA supply will not output less than 9Vdc at the full 500mA load but will output a much higher voltage unloaded or lightly loaded.
- Regulated supplies are rated at any load capacity. A 12Vdc supply will output 12Vdc at any load up to it's maximum current output then past that point the voltage might start to go dowm or the output will simply turn off.
The DV9-500 is a 9Vdc @500mA unregulated power supply. It was selected by our engineers to match the most common IR system configurations while providing a cost effective solution. Unloaded (not connected to the IR-100 connecting block) it outputs around 13Vdc and when connected to a typical 1-5 IR repeater system it outputs about 11Vdc which yields optimum performance in the most common IR system configurations.
The SPS-1212 is a 12Vdc @1.2A voltage regulated power supply. It was selected by our engineers to provide optimum performance for all IR system configurations while providing an energy efficient solution. Unloaded (not connected to the IR-100 connecting block) it outputs a regulated 12Vdc and when connected to any repeater system drawing up to 1.2A it outputs the same regulated 12Vdc. This is the optimum power supply for any IR system.
We recommend the SPS-1212 for large, complex IR systems.
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End of Infrared FAQ