Maker Pro
Maker Pro

IR Leds or Visible ?

colum

Jul 25, 2013
175
Joined
Jul 25, 2013
Messages
175
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

Adam
Dec 18, 2013
5,178
Joined
Dec 18, 2013
Messages
5,178
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

Jun 25, 2014
4,098
Joined
Jun 25, 2014
Messages
4,098
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

Jul 25, 2013
175
Joined
Jul 25, 2013
Messages
175
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

thanks Adam that explains it...colum
 

colum

Jul 25, 2013
175
Joined
Jul 25, 2013
Messages
175
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.
Thanks Gryd3 for that very very good safety advice and advice on use of a digital camera
 

colum

Jul 25, 2013
175
Joined
Jul 25, 2013
Messages
175
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

Adam
Dec 18, 2013
5,178
Joined
Dec 18, 2013
Messages
5,178
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

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

Jul 25, 2013
175
Joined
Jul 25, 2013
Messages
175
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
Thanks Adam for your reply, that clears that up, Be well....colum
 
Top