Q: What are the tolerances on new boards?

[CiTY]

Peter & fellow members,
A quick question, What are the voltage tolerances of the new board? I know it's minimum is around 1.5, and that a 6v 2x123 pack is going to be offered. Will the new LS2 take 6v? And what do you consider the rated max V before we fry the new board(LS2/LS3) in our future mods? I read that the SF-KL1 will take 3-9v...Great range.
Thanks.

 

[Ron Schroeder]

Hi CiTY,

The LS1 and LS2 are boost converter type drivers so their maximum input voltage is only a few 1/10s of a volt over the Vf of the LED. Your practical max voltage is about 3.75V with the LS1 or LS2 and about 7.5V with the LS3. The actual max voltage will vary slightly depending on the actual Luxeon in the head.

The 2 x 123 holder is only for the LS3.

The buck-boost of the KL1 allows higher input voltage than the LS1 or LS2 but is slightly less efficient.

 

[Gransee]

Ron is right on the money. Wayne's circuit is also efficient in size, which allows us to make the most compact regulated (or otherwise) LS in production.

Peter

 

[W4DIZ]

 

[CiTY]

Thanks

 

[Sean]

Will the LS1 & LS2 work ok with 3 1.2v NiMH rechargeables? It technically looks ok but true unloaded voltage will be over 4v. This should drop under load though.

 

[Gransee]

It might work with AA cells. AAA's would definately work.

We tested it with 3, 1/3A cells in series and the rev2 circuit was fine. The LS that I carry is powered by a 2x1/2A NiMH pack.

The trick is to keep the cell size small enough that the load voltage does not rise to much over about 3.4v.

Peter Gransee

 

[Sean]

Sounds good. I was thinking of using 3 1/2A NiMH batteries in the 2x123 TSP with the LS2 & LS3.