LS5 on one 123 cell?

[Double_A]

I am well aware that the LS5 is still in the developmental stage. But I have a question that I guess is directed to Peter.

Do you anticipate the LS5 will be able to run on single 123 cell (at a much reduced light output) in the same manner as the SF KL4 head on a E1e?

Thanks,
GregR

 

[Double_A]

BTTT

No info? or no speculation?

 

[kakster]

No-one knows enough about it yet. We dont know what electronics it will use, other than it will drive a 5 watt LS at around 3 watts. We dont know what configuration the body will be. If its like the current LS with an extended body, 2 cells wont be possible without a dummy battery, and if it's like the ARC AA tailpack, then i suspect you will have to find a 1 cell tail that fits. In my experience, a 5 watter is best paired with at least 2 CR123s, i like to get a minimum of 1 hr of bright, regulated light.

 

[stefx]

To run an LS from one 123 cell, you need a step up converter circuit. To run it from two 123 cells, you need a step down converter, which is fairly different.

Basically, a second switching transistor is involved for a converter which does both step up and step down. This wastes a lot of PCB space and also requires extra microcontroller code and another microcontroller output line.

So my guess is that the LS5 will be straight step down and needs at least 5V to operate. Two 123 cells.

On the other hand, if the LS4 and LS5 electronics are the same, then it will be a combined up/down converter, and the LS5 can run on a single 123 cell, too.

Stef(an).

----

Oh, sorry. This post is totally nonsense. I didn't know the details about the 5W LS. Was thinking it is just a 1W unit with improved thermal management and similar Vf. Please read Rothrandir's post below. Stef(an).

 

[Rothrandir]

the ls5 is a 5watter, so it if it uses 2 123's, that is below the vf of the luxeon, and it will need to step up to drive it in full blast.
the ls uses alien electronics though, so using lower voltages may just allow the lower output ranges :shrug

 

[Gransee]

/ubbthreads/images/graemlins/smile.gif You are close...

Remember the voltage range of the LS4?

Peter

 

[Double_A]

Thank you Peter, that was enough info for me to format a search and find the answer!


GregR


P.S. Here is the info from a prior post from Peter "The input voltage range of the LS4 is 2-6.5 volts which supports a single copia cell. The LS5 may be able to support 1 and 2 cells."

 

[carl]

As an aside, if the LS5 is going to run at 3 watts, won't the new 3 watt LS bulb be a better choice for throw than the 5 watt bulb? I'm assuming since the LS5 is meant for the law enforcement/military market, throw will be of paramount importance, but then again, I really don't know.

 

[stefx]

Hey, maybe my last post wasn't that idiotic.

Because the LS5 has a software controlled power off switch, the series transistor has to be there. This means, the circuit can do voltage step down as well. Step down is also necessary for the dim modes. And for 'tint control'.

Ok, i still guess it has a combined step up/down circuit.

Stef(an).

 

[Gransee]

The LS5 will be able to run on a single 123 cell. The plan is to make the battery packs threads indentical with the LS4.

And yes, both the LS4 and LS5 have a buck/boost circuit. The voltage range should be almost identical.

Understand that with 1 cell, not all the brightness levels may be accessible or last as long. But the levels you can access will be tint controlled and regulated. The uC will be able to really work the battery over if you so choose.

Also, the LS5 will have a longer head to accomodate higher power circuitry. If using it at lower power, you still have to carry that extra bulk. It will also cost more because of the more expensive LED. If you require a single cell light for EDC, the LS4 will be a better choice.

I will know a lot more about what we can promise and not promise when we have a LS5 prototype (February?).

Peter