2 vs 1 LED

[AtomicSheep]

Just wondering what other peoples opinions are regarding using 1 or 2 LEDs for Korry type switches. By that I mean...

The actual Korry switches use 2 lights per indication, so a total of 4 per switch.

What's your experience, is 1 enough or is 2 per indication definitely better?

[KyleH]

All depends on the Lumens the LED puts out and it's spread pattern.
I use 1 LED that has a flat top.

[Mach7]

I have always wired two 5mm superbrights in series. This ensures that you don't get that sun-spot effect with the legend being very bright in the middle and the text on either side sort of fading out.

I also use a piece of very thin white felt, cut to measure, in order to diffuse the light.

[757Simulator]

I'm with Mach7.

[AtomicSheep]

Great thanks guys.

The other question is... do you use filters on white LEDs or coloured LEDs?

[KyleH]

I have Korry's so they already have filters in them, so I use white.

A filter will help diffuse the spread pattern as well.

[757Simulator]

Yes, I most certainly use colored diffusers on all my Korry's as well as annunciators. As for the top legend (Korry / White), I also use a white diffuser. Due to the nature of the light distribution of LED's you will suffer bright areas of the legend without them.

Mitch

[Mach7]

@AtomicSheep

Just FYI since I did a lot of R & D on this matter when I was trying to get the best legend brightness and "look" for my captions and annunciators.

Stay away from the normal colored LED's, instead buy the superbright product, either 3 or 5 mm. They come in every color you will need for your project.

Use very thin white felt cloth on every caption, no matter what the LED color.

The diffuser has to be made of such material that, when the LED's are on,  it will cause the entire cloth or  product to "glow", (using a dark piece of plastic or solid material will not work as you will just get two very bight 5 mm holes shining  through the  material).

For each legend, Wire the two LED's in series using one resistor per each pair of LED's, ( see attachment). You might have to get close to the base when soldering them together, so use an alligator clip to dissipate the heat from the soldering iron.

There are a number of ways to fit the LED's into your existing korry casing. I have actually used 3mm LED's in aircraft specific flight annunciator switchlights. They fit perfectly into the holes, and then I clip just enough off the (a) and (k) anode leads so they press up inside the switch contacts, (which contain little springs) and voila``, all I have to do now is solder wires onto the back of the  annunciator and install resistor(s) upstream of the anode wire.