OT: LED LIGHTING QUESTION

[JimmyinSD]

we have a few smart people in here so I though I would throw this out there.  I am hooking up 2- 12v led lights to my tractor (each fixture has 9 LEDs),  when I hooked up the first one all 9 leds shine brightly,  when I added the second one only 1 led on each light shines,  the rest are dead,  if I unhook 1 the rest light up on the other one again.  Is this a lack of power issue or am I running into some sort of interference on the line that makes them not play nice together?  any help would be appreciated.   I am going to head back out and try running a temporary wire to one of them off a different switch and see where that gets me.

[Guest]

Dumb question, but in your scenario above (strip A and strip B ), you know that strip A works on its own.  Have you tried strip B by itself?  Just want to clarify when you say "the other one works again."  You just running these off of a standard toggle switch?

[Guest]

@El_Padre said:
Dumb question, but in your scenario above (strip A and strip B ), you know that strip A works on its own.  Have you tried strip B by itself?  Just want to clarify when you say "the other one works again."  You just running these off of a standard toggle switch?

yep,  they will both work fine independently of each other.  i thought maybe not enough power so i ran a separate power supply and switch to each light and they do the same thing.   I am thinking that they must put some sort of  noise in the ground or something that screws up the other one.  when i get time I am going to try separating the grounds...maybe thats the issue.

[Guest]

well.... it was the ground.   left the positives together and ran one ground right to the base of the lamp and they both shine like broadway.  thanks Padre.

[Guest]

Physics will kick butt every time, no matter your intentions.   Parallel vs series in dc circuit, Thevenins theorem will illuminate the issue

[Guest]

@BigAl99 said:
Physics will kick butt every time, no matter your intentions.   Parallel vs series in dc circuit, Thevenins theorem will illuminate the issue

Well it's kind of a hybrid solution.  The positives are still in series,  it's just the grounds that are parallel,  but yes it was a butt kicker for a bit.  Not sure why nothing is ever as easy as it should be,  this was suposed to be a simple swap out of the old incandescents with brighter LEDs....but nooo.  Oh well. It's done defintely brighter and they should be pulling less juice to boot.

[Guest]

@JimmyinSD said:

@BigAl99 said:
Physics will kick butt every time, no matter your intentions.   Parallel vs series in dc circuit, Thevenins theorem will illuminate the issue

Well it's kind of a hybrid solution.  The positives are still in series,  it's just the grounds that are parallel,  but yes it was a butt kicker for a bit.  Not sure why nothing is ever as easy as it should be,  this was suposed to be a simple swap out of the old incandescents with brighter LEDs....but nooo.  Oh well. It's done defintely brighter and they should be pulling less juice to boot.

Grounding issues can certainly give anyone fits. It is one of the things that will cause head scratchers far more than most other electrical quirks.