? mounting Amber LS emitter-does 1 need 2 isolate

[robstarr-lite]

are amber LS emitter die [heat sinks] electricaly different than the red/white/blues etc....i seem to be "shorting" out this amber LS i recently aquired when i mounted it (replaced it) where i had a 1 watt white LS . i'm mounting it on a tin plated pcb substrate ...the substrate uses the batteries ground in the circuit........meaning i guess is the + on the amber LS connected to the die's heat sink and thus one has to electrically isolate an amber die in order to use it in this method?....did a search but came up nadda...thanks, rob

 

[Rothrandir]

yes, the amber slug is positive.

red, red/orange, and amber all have a positive slug.

another concern, you say you're using the amber in place of a white luxeon?
the reddish series like less volts than the whitish series, and combined with the fact that they don't tolerate heat as well, you might really want to consider adding some resistance or something if you aren't already doing so.

 

[robstarr-lite]

thanks, doing the resistance thing ...... but ..i did this first to a red high dome and it works fine....originally thought only early reds had this issue....of course it could also also be the fact i am using non conductive thermal compound and i actually put enought so i am not shorting it [red]....i guess a layer of myar tape placed between the die and substrate is insurance..any other insulating ideas? and thanks

 

[IsaacHayes]

black sharpe marker painted over the surface has been used before to isolate the materials before mating. also don't overdrive these red family luxeons, as they dim when you do! keep current 400ma or lower!