# Electronics design question



## ncrc5315 (Jan 25, 2014)

I'm trying to design a PCB board, and my question is, is there a way to attach a fiber optic filament to a SMD LED?


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## wvgca (Jan 21, 2013)

in commercial applications, it's quite common to use 'light guides' or light pipes to guide fiber optic strands into smd leds ... for hobbiest use i suppose that you can hot glue the filament directly onto the led ??
I haven't actually used these devices for commercial use in real life though ?


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## MichaelE (Mar 7, 2018)

https://www.mouser.com/new/optoelectronics/led-indication/led-light-pipes/bivar-zero-light-bleed-rigid-pipes/n-b1d20Z1wgx5k


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## gunrunnerjohn (Nov 10, 2010)

ncrc5315 said:


> I'm trying to design a PCB board, and my question is, is there a way to attach a fiber optic filament to a SMD LED?


Can you describe the application? In the simplest form you can use a transparent glue like CA adhesive to simply glue it to the SMD LED. What exactly are you trying to accomplish?


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## ncrc5315 (Jan 25, 2014)

This is actually for work. I have a customer, and on their air handling units, they have multiple devices tied to the safety circuit, with nothing to indicate which device is causing the problem. The safety circuit is 24VAC, and I was thinking of putting a diode, current limiter, in series with an LED, and use a fiber optic filament to get the light outside of the device. Just looking for something down and dirty.


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## gunrunnerjohn (Nov 10, 2010)

You could use a thru-hole 2mm post LED and heatshrink the fiber to the post, I've done that with excellent results. Truthfully, for a 24V circuit, why not just poke the post LED out a small hole?


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## wvgca (Jan 21, 2013)

i suppose something similar to the following would work, just a simple light pipe ..the mount [surface mount], on the SMD LED, and a lens cap, light pipe to panel, in a suitable size, just add fiber optic strands .. a pretty cheap solution, starts at 53 cents, lol





https://i-fiberoptics.com/light-pipe-connector.php


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## ncrc5315 (Jan 25, 2014)

Thank you for you're responses.



gunrunnerjohn said:


> You could use a thru-hole 2mm post LED and heatshrink the fiber to the post, I've done that with excellent results. Truthfully, for a 24V circuit, why not just poke the post LED out a small hole?


On some of the devices, I'm limited for space, therefore, can't pick where I place the LED, and on others, they will be inside the air handler, and directly in the air stream. I figure with a fiber optic, I can place the LED and circuit where it fits, and be able to thread the fiber optic out through a crack. But I'm certainly open to suggestions.


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## MichaelE (Mar 7, 2018)

Have you investigated the parts I referred you to at the Mouser link I provided?

These lightpipe mounts directly mount to a SMD LED.


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## ncrc5315 (Jan 25, 2014)

MichaelE said:


> Have you investigated the parts I referred you to at the Mouser link I provided?
> 
> These lightpipe mounts directly mount to a SMD LED.


Yes, I'm getting several for evaluation.


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## MichaelE (Mar 7, 2018)

If you have questions, they have trained technicians to speak on the phone with you, not order takers that don't have a clue.


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## ncrc5315 (Jan 25, 2014)

Thanks!


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