IR Leds or Visible ?

colum · Jan 22, 2015

I want to run about 75 ft of Fiber Optic cable as an ON Off type of switch.. All of the LEDs that I have are IR, so my question is...Is IR better for long transmission and receiving or is visual Leds better since the activating light can be adjusted in intensity.
Would it be better to use an adjustable visible light source and an IR receiver as they seem fairly sensitive to both

Anyway visible light receivers are a little hard to find

Thank you for reading this
colum

Arouse1973 · Jan 22, 2015

For glass fibre cables it is better to use IR because of it's greater wave length. This gives less attenuation versus visible light.
Thanks
Adam

Gryd3 · Jan 22, 2015

You can indeed adjust the intensity of an IR LED just like any other LED.
You can use most digital camera view finders to detect the output from the IR LED.

Please note that commercial fiber uses quite intense IR, please practice safe handling of fiber and never look into the end of an optical fiber! Just because you can't see IR does not mean it's not there.

colum · Jan 23, 2015

Arouse1973 said:

For glass fibre cables it is better to use IR because of it's greater wave length. This gives less attenuation versus visible light.
Thanks
Adam
Click to expand...

thanks Adam that explains it...colum

colum · Jan 23, 2015

Gryd3 said:

You can indeed adjust the intensity of an IR LED just like any other LED.
You can use most digital camera view finders to detect the output from the IR LED.

Please note that commercial fiber uses quite intense IR, please practice safe handling of fiber and never look into the end of an optical fiber! Just because you can't see IR does not mean it's not there.
Click to expand...

Thanks Gryd3 for that very very good safety advice and advice on use of a digital camera

colum · Jan 23, 2015

i was under the impression that an Led light brightness could not be adjusted, if it called for a 300 ohm resistor at 12v that's what it needed
Thanks for your advice...colum

Arouse1973 · Jan 23, 2015

colum said:

i was under the impression that an Led light brightness could not be adjusted, if it called for a 300 ohm resistor at 12v that's what it needed
Thanks for your advice...colum
Click to expand...

Hi Colum
You can adjust the light output of an LED from nothing to it's maximum rating by changing the current. The life of the LED is also effected by current, but even at maximum current they still last a very long time. You can also pulse them at current greater than the maximum but you would have to consult the data sheet for that information.
Adam

colum · Jan 23, 2015

Arouse1973 said:

Hi Colum
You can adjust the light output of an LED from nothing to it's maximum rating by changing the current. The life of the LED is also effected by current, but even at maximum current they still last a very long time. You can also pulse them at current greater than the maximum but you would have to consult the data sheet for that information.
Adam
Click to expand...

Thanks Adam for your reply, that clears that up, Be well....colum

Arouse1973 · Jan 23, 2015

colum said:

Thanks Adam for your reply, that clears that up, Be well....colum
Click to expand...

And you mate!

IR Leds or Visible ?

colum

Arouse1973 Adam

Gryd3

colum

colum

colum

Arouse1973 Adam

colum

Arouse1973 Adam

Anyone have experience with IR LEDs?

50 IR LEDs powered by 9v battery??

Opto or IR sensor, what type?

LEDs

IR Light's

IR Sensor

LED IR

Switching leds