Question about led strips and rings

[Htmlhuh]

First off hello to everyone. I am new here and wish I would have joined a long time ago. Great place for valuable information.

Now down to business. Why are LEDs arranged in groups of 3 when they are made in led strips or led "halos" (rings). I noticed there are (diodes or resistors?) in line with them. Basically I want to know exactly what those little black things are and what do they do, why do they do it, and why every 3rd led. I know it is possible to also have an led ring with the diodes or resistors in line but not made onto the ring they are actually in a separate box. That is the design I like better because if one goes out it can be easily replaced without having to solder on the rings. I build custom car headlights and use a lot of led rings and strips and just want to learn more about the products that I use. Thank you all very much.

 

[RoGuE_StreaK]

Extremely roughly speaking, most of the LEDs require a forward voltage of 3.something volts, so whack three of them in series and it needs 9 - 10Volts-ish, so for running off a ~12V supply they then add a resistor ("little black thing") to drop the voltage and limit current. It mostly works, but is far from "ideal".
Check out the oft-referred linear1 site.

"Custom car headlights" probably goes against a lot of rules here. Not to mention you really should know exactly what you are talking about with LEDs before even contemplating doing such a thing, let alone charging for it.

 

[Htmlhuh]

I don't actually build the strips or rings. I open the headlights and install the strips or rings (whatever the customer wants) and then reseal them and connect them to their respective rgb control box which gives them their power and on/off switching capability via remote usually. Sometimes they are solid color leds connected to an on/off switch. I always use a properly fused relay when installing anything in a customers vehicle so as far as the "headlight builds" I know what I'm talking about and do it quite well which is why my customer base is as large and as constant as it is but enough about that I merely want to know the technical details of what I do that way I can understand the workings better and possibly devise a more convenient system for me. For instance lets say I have a 10" led ring just for numbers sake because that's quite large. That ring has 30 LEDs (again number sake only) so it should have 10? Resistors. Well typically those resistors are built onto the led ring itself one after or before every three LEDs. If one of those resistors fail it causes 3 LEDs to go out. In order for me to fix that I would have to again open the lights, remove the ring, replace the resistor and any damaged LEDs, and then reseal the lights and reinstall. It's a PIta and I lose a bunch of money doing it. Well I have come across some new rings where the LEDs are on the pcb but it has no resistors. There's a little box that goes before the the power supply with some resistors and such in it on a small board. Now the components in the box look much different than the tiny resistors on the backs of the other led rings. I want to know all about the two styles and why they work and which is better if any but hopefully the second style because if a resistor fails, I just replace the little box and boom my led rings are good as gold again and I don't have to remove the headlights or take them apart. Hopefully somebody here can help. I can post picture of all of this if anyone would like. Thank you all once again.

 

[-Virgil-]

-.- -.-

 

[RoGuE_StreaK]

Morse for "K K"?

 

[AnAppleSnail]

Morse for "K K"?

Emoticons are a densely packed language. It's code for "Illegally modifying headlights is illegal." Code for "Installers not understanding electrical equipment and ways it fails is worrying." Code for "You can't reseal sealed lamps."

 

[-Virgil-]

Code for "Sorry—can't help. The lighting modifications/products you're asking about are illegal and unsafe. Rule 11 of this board prohibits advocating illegal or dangerous activity. Please stop now, thanks." (Also code for everything AnAppleSnail said).

 

[Htmlhuh]

I don't believe you gentlemen are exactly knowledgable about your laws...they are quite legal for off road use....

 

[Htmlhuh]

Thanks for everything though. I'm switching over to hidplanet. Just seems the people here are "set in their ways" good day to all. Any mods feel welcome to close my account as I will not be back.