12v Infrared LEDs?? Need help.

Tighe

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OK, so I am trying to fix this opto board and it looks like these Infrared LEDs are running on 12v. The only problem is that I can't find a 12v infrared LED anywhere online. The highest I have seen is 1.5v. There are 270 ohm 2watt resistors before these LEDs, does that drop the amperage enough so that 12v won't blow them out??

IMG_20120702_185131.jpg
 
Answered my own question:

That is a 1.5v Infrared LED there. Oh and BTW, you can use a camera to check if Infrared LEDs are functioning, but just not on a iPhone. They put a infrared filter on the lens so people can't use it to take photos through clothing. Not so on my Android phone.

IMG_20120702_190523.jpg
 
Usually you'll find a 1/4 watt resistor before a single LED. 2 watts seems like overkill. Also 270 Ohm seems too low.

check out this site for calculating what size resistor you need for a given LED:

http://led.linear1.org/1led.wiz
 
Usually you'll find a 1/4 watt resistor before a single LED. 2 watts seems like overkill. Also 270 Ohm seems too low.

check out this site for calculating what size resistor you need for a given LED:

http://led.linear1.org/1led.wiz

Ah, looks like there are two of the resistors in series giving you 540 Ohms which would make sense.
 
Vsupply - Vled
-------------- = Resistor is ohms
iLED

If the voltage of the power supply is 12v and the LED runs off 1.5 with a current of 20ma, then...

12v - 1.5v
---------- = 525 ohms
.020

Enjoy!
 
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