Cheap LED lights

[DrewKaree]

Picking up a strand of the LED Christmas lights seems WAY cheaper than buying them individually, but being as I know nothing about wiring them up, how would one go about figuring out all the added fiddly bits that seem to be needed in an LED circuit? 

[RandyT]

Picking up a strand of the LED Christmas lights seems WAY cheaper than buying them individually, but being as I know nothing about wiring them up, how would one go about figuring out all the added fiddly bits that seem to be needed in an LED circuit? 

I've explored this a little, but haven't actually played with the real thing.

But I'm thinking that the old adage about getting what you pay for is going to come into play.  Christmas tree lights don't really need to be that bright to be effective, there needs to be a lot of them and they need to be cheap.  That makes them perfect candidates for indicator lighting, but not necessarily for things like lighting buttons and such.

You would probably have to do some tricks with the wiring as well.  They seem to be wired in series and are fed by 24 to 36v power supplies.

There might be some decent ones out there though.

RandyT

[BobA]

I had a cheap string go half dead.

[Infinity_Yak]

www.lsdiodes.com

You want cheap LEDs?  They've got cheap LEDs!

Seriously, if you need LEDs of any color/brightness/size, they're your hookup.  I made a huge order for a bunch of different LEDs, including RGB LEDs, and it was less than half the price of the nearest competitor.  I have nothing but good things to say about them!

[RandyT]

Seriously, if you need LEDs of any color/brightness/size, they're your hookup.  I made a huge order for a bunch of different LEDs, including RGB LEDs, and it was less than half the price of the nearest competitor.  I have nothing but good things to say about them!

The LEDs this outfit sells are not optimal for lighting buttons from the bottom (above the microswitch.)  The angle is wrong.

Probably fine for other purposes though.

RandyT

[DrewKaree]

Seriously, if you need LEDs of any color/brightness/size, they're your hookup.  I made a huge order for a bunch of different LEDs, including RGB LEDs, and it was less than half the price of the nearest competitor.  I have nothing but good things to say about them!

The LEDs this outfit sells are not optimal for lighting buttons from the bottom (above the microswitch.)  The angle is wrong.

Probably fine for other purposes though.

RandyT

They seem to have a single LED that might work, but it only comes in one color (white or blue, I can't remember which), as well as a few indicator LED's that might not be so obnoxiously bright.  They seemed a bit pricey to me, but this is in comparison to how much an entire string of lights costs.

[webgeek]

The LEDs this outfit sells are not optimal for lighting buttons from the bottom (above the microswitch.)  The angle is wrong.

If you diffuse the light using the white plastic technique (for microswitch buttons) then it seems like it would work fine. Is there someone else wrong with them? Thanks!

Mike

P.S. Randy, I sent you a PM, thanks!

[Roughy]

May not be the cheapest around, but coming from Alaska, I've received all my orders in about 2 days.  I consider that to be just wicked fast and outstanding for eBay.

http://search.ebay.com/_W0QQsassZaxioms1QQhtZ-1

(Plus just noticed that they have this: Glow in the Dark Powder and I'm really trying to think of a kick-ass way to integrate that into a cab... )

[RandyT]

The LEDs this outfit sells are not optimal for lighting buttons from the bottom (above the microswitch.)  The angle is wrong.

If you diffuse the light using the white plastic technique (for microswitch buttons) then it seems like it would work fine. Is there someone else wrong with them? Thanks!

You can try that, but you will probably just end up with a hot spot that fades off quickly.


Here's something to note about LED brightness ratings:

Luminous flux is measured in lumen, while luminous intensity is measured in lumen per steradian, also called a candela.  LED's are measured in candela/1000 or mcd.

A more accurate way to describe the brightness of the LED is to use the luminous flux numbers.  These are constant regardless of angle.  MCD goes up very quickly as the angle is reduced.  An example of how misleading this can be is shown below:

A 10,000 mcd LED at the typical 15 degree viewing angle sounds very impressive.  However, this LED has a luminous flux of only 0.5375171944259994

A 3,300 mcd LED with a 45 degree viewing angle doesn't sound so great, but has an luminous flux of 1.5782684086665921, which is about  3 times that of the 10,000 mcd LED!


It's all about putting the light where you need it and picking the right part for the job.

RandyT

[webgeek]

Ah, good to know that about the brightness of LEDs.


Sorry that I wasn't more specific on the lighting technique. I was refering to the one illustrated here:

http://forum.arcadecontrols.com/index.php?topic=37034.msg373712#msg373712

It seems that this would let you get away with a lot lower MCD level; particularly if you angled the LEDs so they beamed into the ring and not into the button. I'm thinking that painting the ring, minus the inside center edge of course, with silver paint would help too.

I also wonder how much of a difference it would make if the white ring were threaded onto the button directly...

I have all the materials here, might have to play with it a bit. Thanks!

Mike

[RandyT]

Sorry that I wasn't more specific on the lighting technique. I was refering to the one illustrated here:

http://forum.arcadecontrols.com/index.php?topic=37034.msg373712#msg373712

It seems that this would let you get away with a lot lower MCD level; particularly if you angled the LEDs so they beamed into the ring and not into the button. I'm thinking that painting the ring, minus the inside center edge of course, with silver paint would help too.

Thanks for clarifying.    Angle will be less important as this one relies almost entirely on the light bouncing and refracting through the plastic.  Higher flux will always be better if you want your buttons to appear to be lit in normal room light though, so keep that in mind.

RandyT