Author Topic: RG or RGB SMD LED within 4.1mm dia  (Read 1258 times)

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Offline Richard CrowleyTopic starter

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RG or RGB SMD LED within 4.1mm dia
« on: January 28, 2019, 06:45:36 pm »
I have an application (low-profile video switcher control panel) where I would like to use these Panasonic EVPADK04K switches.



I need R/G lighted indication (industry convention: Red = on-air, Green = preview)

These switches are nice low-profile and provide a 4.1mm "hole in the middle" to deploy the lighting.

But I am trying to find a nice bright R/G LED solution that would fit into that 4.1mm dia space constraint.
I fear that the ordinary SMD LEDs that will fit within the 4.1mm diagonal are not bright enough to shine through the button cap.
Unless I can find molded buttons, I am fabricating my own from white translucent acrylic.

There are SMD LEDs that mount from the back-side of the PCB, and shine through a hole in the PCB.
But I don't know what is the proper name for that style?

Ideally I would like something like a fully-controlled RGB component with integrated controller (what AdaFruit calls "NeoPixel")
But those are much to large to fit within the 4.1mm dia space.

I suppose, worst-case I could simply use ordinary 3mm RGB (or RG) LEDs poked in from the back-side of the PCB,
and fold over the leads to create a DIY surface-mount kludgy solution.
 

Offline ajb

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Re: RG or RGB SMD LED within 4.1mm dia
« Reply #1 on: January 28, 2019, 07:59:16 pm »
If you really want RGB, what about a second PCB with the LEDs mounted behind the first with the buttons?  You may need a light pipe or lens to get better light coupling, there are a number of simple cylindrical light pipes that might work.
 

Online mikeselectricstuff

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Re: RG or RGB SMD LED within 4.1mm dia
« Reply #2 on: January 28, 2019, 08:04:40 pm »
2x2mm RGB LEDs are readily available and fairly bright
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Offline Buriedcode

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Re: RG or RGB SMD LED within 4.1mm dia
« Reply #3 on: January 28, 2019, 08:56:53 pm »
A RGB PLCC4 might also fit in there ( 3.2 x 2.8 ) but they tend to be extremely bright.

Edit: stupid emotes
« Last Edit: January 29, 2019, 12:04:55 am by Buriedcode »
 

Offline Mr.B

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Re: RG or RGB SMD LED within 4.1mm dia
« Reply #4 on: January 28, 2019, 09:03:16 pm »
I have used Cree 2mm x 2mm PLCC4 in small/tight spots.
These ones are pretty bright.
They were too bright in my particular application and I ended up using them with 35% PWM.

Datasheet here:  https://nz.mouser.com/datasheet/2/90/1273-CLMVC-FKA-1519109.pdf
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Offline Domagoj T

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Re: RG or RGB SMD LED within 4.1mm dia
« Reply #5 on: January 28, 2019, 09:14:48 pm »
 

Offline LapTop006

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Re: RG or RGB SMD LED within 4.1mm dia
« Reply #6 on: January 29, 2019, 02:42:15 pm »
It somewhat depends how you're planning to cover them, you need some diffusion to avoid a bright point source anyway, but even standard 0603 indicator LEDs run at full power are almost certainly brighter than you'd ever want if you use modern parts.

Red & Green are on the dimmer end for LEDs, but at 5-10mA should be plenty bright enough, even through a lossy diffuse layer. (For blue < 1mA can still be obnoxiously bright)
 


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