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Why we use 2 IR emitters to design a IR remote control?

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fokalfokal

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IR remote control

hi everyone.please help me why we use two ir emitters (ir led) instead of one ir emitter to design any ir remote control. if you help me, i will be pleased....
 

cyberblak

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Re: IR remote control

Don't know about the specific design you refer to, but if both LEDs are connected to the same signal source it helps boosting the output signal.

cyberblak
 

VVV

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Re: IR remote control

Basically, it's like having tow light bulbs: you get more light.
The same applies to LED's. In the old times, when the receivers were less sensitive, there were RC's with up to 5 LEDs.
Usually they are connected in series, if you have a high enough voltage to drive them, otherwise each LED should have its own series resistor.
 

docel

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Re: IR remote control

Hi,
!. IR Leds have to be driven at higher current if they are pulsed.
Usually Range is bad due to low current. Pulse driven IR LEDs should be in the range of 300ma to.1A, depending upon the pulse/modulation freq.
2. Check out series resistance to the IR LED. Do not calculate for dc current if used in 38kHz circuit. use 6- 15ohms at 5V Vcc.
3. If you use 2 or more LEDs, check or change drive transistor transistor (rating min. 2A).
4. Increase Vcc to 9v. as is.

docel.
^Anything is possible....
After YOU Proove it !!!
 

    fokalfokal

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ikarakaya

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Re: IR remote control

if you need boosting signal strength try using high frequency opamps for the emitter side. It works well. But if you want to control more then one device it should be better doing it with software.
 

Sibtain

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Re: IR remote control

hello my friend i am working on this project and have almost succeeded in decoding a sony protocol i will send you information when i complete it
 

Alan69

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Re: IR remote control

The other aspect is beam angle. If you use two, and turn each out from center some the remote's IR will be much more visible across a wide angle. Things cost money, and economics plays a large part in large quantity business decisions. If two narrow angle LEDs give the same beam power but for half the total cost of a high power LED, then it can make sense if your build price with the extra LED doesn't outweigh it.

This was a lot more common with lower power IR LEDs of the 80's and early 90's. I haven't seen much of this since the mid-90's, when the modern type high power LEDs started getting reasonably priced..

More is always better though except for power consumption. When you want a good solid and reliable link, 2 or 3 or 4 makes sense, they're pretty cheap vs a single point failure with 1 LED going bad.

Alan
 

Praful

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Re: IR remote control

Dear, folkalfolkal insted of one emiter two works best so some professinals use it.twice:D
 

edzyj

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Re: IR remote control

ir led have emit angle,two led also can increase emit angle.
 

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