L4 statement from SF regarding 9V compatibility

FalconFX

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There were a lot of talk about the compatibility of the L4 to a 9V configuration before, so after getting this message from a decided anonymous CPFer here, I'll post, verbatim, what was said:

Dear [CPF Member],

Thank you for the inquiry and continued support of SureFire products. The KL4 can run off of three 3 Volt lithium batteries. The output will remain the same but runtimes will be extended. I do not data on what the runtimes would be for an L4/KL4 in a 9 Volt configuration. We never has to test this scenario as we do not build a 9 Volt version of the L4/KL4.



We are dedicated to providing world-class customer service and welcome future inquiries or comments.

Best regards,
George D. Syrengelas
Technical Support Representative
[telephone deleted]


I'll let you interpret it as it is... Personally, this means the UBH and McLux 3X123 bodies will have another partner to tangle with...
/ubbthreads/images/graemlins/grinser2.gif

<font color="brown">--Modders, feel free to move this if you believe it's more appropriate elsewhere... </font>
 

Icebreak

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Falcon FX -

Do I have this right? Three parties involved in this communiqué? Yourself, the helpful and anonymous CPFer and the SF TSR, Mr. Syrengelas.

This is very interesting information. Thank you.
 

McGizmo

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I would highly suggest that someone put a meter in the system and measure the current being drawn by the converter on 3 cells. The circuit is a boost circuit and it may be that internal resistance of batteries and the voltage drop across the circuit will take some of the bite out of the DD but I think in DD you will be. Certainly on a bench power supply, I saw the current jump big time around 7 volts as I recall. The KL4 is not a big hunk of AL like some of the 9 volt DD's we know. /ubbthreads/images/graemlins/grin.gif

- Don
 

FalconFX

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Icebreak, I'm just posting the e-mail that was given to a CPF member regarding the usage of 9V, so yep... A three way triad...

Pi_is_blue, I haven't run the KL4 with 2x Copia/Pilas yet, but the 168B yielded me at least 40 minutes of runtime, at least until I figured it was dimming too far and fast, and it was shut off to prevent the battery from auto-shutdown...
 

FalconFX

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Well, personally, I wouldn't dare run the L4 (or any other 5Wer) DD off of 9V, unless it's coming from Charlie or one of the numerous top-modders here...
/ubbthreads/images/graemlins/grinser2.gif
 

Bullzeyebill

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Thanks, Choua (FalconFX), for posting this thread for me. IL asked Choua to post this statement from SureFire because I do not know how to post an e-mail in a thread. Got to learn. I posed the question to SF because I had a feeling that they would use the same electrics, buck-boost + regulation in the KL4 and KL5, much the same as they did with the KL1 and KL3, though I always knew from the get go that the KL1 could take 9 volts, not from SureFire, I learned this from the Led Museum, and other sources. I am sure that it will be safe to use 9 volts with the KL4 (L1), or my response from SF would have been, "Don't do it". Bill
 

McGizmo

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Hi guys,

I just did a bench test and will report my findings. I'll make no judgments and of course this test was made with one KL4 sample so YMMV.

I have a loose KL4 driver as a result of installing a BB in a KL4 mod. I put a .1 ohm resistor in series with a 5W LED and powered the circuit with 6 volts and saw 660 mA going to the LED. I then took 3 partially depleted SF123's in series as a power source to the KL4 circuit. The LED had 1 amp passing through it. These batteries came from a 3 cell light that I had been using with a P91 LA. I determined the current by measuring the voltage drop across the resistor. I used a Fluke 189 meter for the test. There is likely error in my measurement but it is clear from both bench testing with a $500 variable power supply as well as now with the three used cells that the constant current driver of the KL4 does NOT maintain the *designed* current level with the input from 3 123 cells.

- Don
 

Bullzeyebill

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Don, thanks for your test. The KL1 and KL3 seemed to be the same circuit, as they could both use 6 or 9 volts, or was that an overload for the KL1? I quess the question is, will 9 volts really hurt the KL4 (L4)? Did SF overbuild the circuit to handle 9 volts maybe, and resultant increase in current, and why did they not warn me about dangers of too much voltage? Just questions.

Billl
 

Glow Bug

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I was told via email NOT to run the KL4 on 9 volts unless you were willing to risk damage to the LED or circuit. This came from the man himself. /ubbthreads/images/graemlins/ooo.gif
 

McGizmo

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Bullzeyebill,

The KL1 and KL3 are not the same circuit. The KL1 has a buck/ boost so it can take Vin below (1 cell - boost) as well as above (2 and 3 cells - buck) the Vf of the LED. The KL3 has a buck circuit which can take 2 and 3 cells; both above the Vf of the LED.

If the KL5 is indeed capable of handling 2 and 3 cells, it will by needs be a buck/ boost circuit as well since the Vf of the 5W falls between the Vin of 2 and 3 cells.

Thanks Glow Bug.

- Don
 

Beretta1526

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It's my gut instinct that the circuit for the KL4 is a boost circuit.

If PK has told someone that it's not recommended to run on a 9V platform, it's mostlikely a boost and putting 9V to it could overheat the circuitry quickly. You know how warm these get already.
 
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