Can a XR-E or Seoul P4 handle U2 circuit?

So, I've been having crappy customer service from Surefire (or lack there of) when I tried contacting them several weeks back through several emails (called them as well and was directed back to email because they said it's some out-of-country jargon).
Anyways, does anyone know if the new generations of LEDs (Cree XR-E and Seoul P4) would be able to handle the circuit in the Surefire U2 ultra? I'm seriously disappointed by Surefire and would love to have someone mod mine with one of these LED.

yeah, i'd like someone to mod mine with a seoul too.

The U2 uses a boost circuit and would fry a Cree or Seoul P4.

If you used a single CR123 and a spacer, it might work.

Iono kak gnarmin would know hopefully he'll chime in. I think it woudl be nice but the U2 should be putting out around 6.0Volts to drive the Lux V and its Vf of 6 volts. Unless the U2 controls its voltage in order to change its current, I think it would need a completely different circuit or 2 emitters. Imagine more than 3 times the light with equal runtime. Other than that as far as I know it is 6 volts and current limiting.

BayMoe said:

I'm seriously disappointed by Surefire and would love to have someone mod mine with one of these LED.

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Why are you disappointed with SureFire? It was unclear to me why you called/emailed them... if it's asking about their future lights, or the ability to mod their lights, they don't say much (if anything) about either things. :shrug:

jch79 said:

Why are you disappointed with SureFire? It was unclear to me why you called/emailed them... if it's asking about their future lights, or the ability to mod their lights, they don't say much (if anything) about either things. :shrug:

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Sorry for being unclear. The Lux V in the U2 blew several months back. I emailed them at the time and clearly stated that I'm in Canada and asked to send it to them and they responded by telling me to call them. Suffice to say, they're giving me the run around and i'm sick of this lack of support for my now expensive paperweight.

Users are using the 18650 in their U2s right?

If this powers the luxV, then I suppose a single CR123 with spacer will also end up 'boosting' to 6v+ due to the circuit?

I do not know what happens in Surefire lights (because I never owned one), but are you sure that the circuit didnt blow? The LED doesnt seem like the likely problem, since it takes a lot to kill the LED under normal conditions.

Is the LED physically damaged? Did the output of the LuxV dim to nothing or change color drastically before it "blew"?

Was the batteries inserted backwards? Was anything inserted into the flashlight to cause something to short to the body (the ground or negative)? Did anything break loose in the light, like a component from the circuit? If you would smell the circuit, does it smell like it has burnt component?

If anything, try connecting a small battery pack (4-5 AA alkalines in series) to the LED directly (taking note to the polarity). You may have to de-solder one of the wires from the LED that goes to the circuit. If it does not light up at all, then the LED may be gone (do to a reverse voltage or some other odd reason). If it does light up, then the LED may be fine. If the LED is fine, then the circuit or the flashlight wiring is at fault.

What batteries does this take? If it uses a boost circuit to raise the voltage for the LuxV, and the LuxV has a short internally or an open circuit (due to a blown internal ESD diode - it happens), then the circuit could be damaged as a result. Some circuits do not like shorts, and many boost circuits really dislike open circuits. The circuit tries to boost the voltage too high because it does not sense an LED, so this can burn up the switcher chip on the circuit. I learned from the Fatman boost circuit.

I really do not know. What I told you is just what I learned from my experience with bad problems that occurs to LED and their driver circuits. I would investigate further into the matter and not assume right away that the LED is burned up (which it can, I suppose). You may hook up the new LED and it may get burned up right away due to a faulty circuit. If you have absolutely no clue what went wrong, just replace the LED with the desired SSC P4, and change out the circuit with one of the drivers from the Sandwich Shoppe. They are small enough that they should fit in the original circuit's place and it should operate much safer and more efficient (since it is specialized for your new LED). I always hate when the strangest things happen to what seems like perfectly fine LEDs. That happens! Well, good luck and keep us posted!


-Tony

The emitter did blow. There is some residual light when I turn it on, but only 1 die out of the 4 is VERY dimly lit. It is so dim in fact, that a have to look closely to determine there is light at all. I cannot check the voltage across the leads because the head of the light is secured with loctite. However, other members here are able to disassemble the head through means of heat and elbow grease.

Wow. My customer service experience with Surefire has been wonderful--they've given me service above and beyond reasonable expectations, I thought.

I'm sorry your experience is so different.

I've had great CS from Surefire and I'm in Norway... I would give them another call and send it in. There are one or more Surefire people on these boards and one of them might chime in.

If you open it up and it turns out a faulty circuit killed the led you voided your warranty and still have a dead U2...

Sverre

I really do wish my interaction with them went as smoothly as yours. =(
In response to Gryloc, the LED blew while I was using it to illuminate my video card. It was on level 4 for probably 5 or 10 minutes when it went sour. I heard someone mentioned that they modified their KL6 with a Seoul P4 emitter and was a monster thrower, but I'm not sure if the circuitry has been changed out or tinkered with.

i know it will work, 4sevens did it, as did another fellow on the forums.

If you want to try this safely for the U2 (not necessarily for the XR-E or P4 emitter), test it with the XR-E or P4 in parallel with the LuxV. If the XR-E or the P4 dies, the LuxV is still there to keep the driver cct from blowing (assuming the U2 is not o/c protected). Because of its higher Vf, the LuxV should essentially not affect the circuit with the other emitter in place.

Going that route, would that not send the same voltage going through the LuxV of ~6V to the Cree or Seoul emitter? I believe that's going to be too much for the new emitters. Definitely still worth the shot if I can get my expensive paperweight to work once again.

Edited for double posting.

BayMoe said:

Going that route, would that not send the same voltage going through the LuxV of ~6V to the Cree or Seoul emitter? I think that's going to be too much for the new emitters.

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If the driver is constant current, it will establish the set current for the level setting. It will reach that sooner (at a lower voltage) with the XR-E/P4 than the LuxV. At the lower voltage required by the XR-E/P4, the LuxV will "appear" as a very high resistance and little to no current will pass through it unless the XR-E/P4 burns out. If the XR-E/P4 burns out in open circuit mode, the LuxV then completes the circuit as per normal configuration for the U2.

I hope that's clarfied things a bit.

Paul

It does indeed Paul. Thanks for the clarification. I feel a little more confident that it is a constant current circuit cause I remember someone measuring half the current with each level down of the selector ring. Now, to get my hands on a Seoul emitter and someone who's able to crack that U2 head open for surgery. I think I'm done with LuxV flashlights from here on out. The L4 and L2 fills that department well.

I personally have had great service from SF if you want to get rid of you paper wieght just chime me and I'll take it off you hands, As per my experience I dropped it off and 20 days later got it in the mail (walk in RMA) same light fixed my stiff selector ring and everythign is happy for me I had a serious lottery winner maybe Xbin whats the xbin battery current anyways? :naughty:

BayMoe said:

The emitter did blow. There is some residual light when I turn it on, but only 1 die out of the 4 is VERY dimly lit. It is so dim in fact, that a have to look closely to determine there is light at all. I cannot check the voltage across the leads because the head of the light is secured with loctite. However, other members here are able to disassemble the head through means of heat and elbow grease.

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Surefire changed the RMA system they use a while back. They have made it a royal pain for anyone outside of the US. I love Surefire flashlights but I've received nothing but headaches dealing with the RMA department. If you do want it replaced don't bother requesting an RMA, just send it in via tracked mail with delivery confirmation. Call them up two days after they have received it and they will have assigned it an RMA number. This is exactly what I did after a customer service rep there suggested it to me. Other reps have said thats not how its supposed to be(and I believe them) but any emails I've sent requesting an RMA number have gone unanswered and calls to customer service say to email as they can't provide an RMA number on the phone to customers outside of the US.


That said I think a Cree or Seoul emitter would be very nice in a U2. I don't know about two to three times the light though, a good U2 is 100 lumens or more out the front end. A Cree putting out 200 LED lumens may only get 150 lumens out the front end. Still a very nice improvement and with a longer battery life as an added bonus.

The power supply in the U2 does seem to be current driven. I have heard it works with Cree emitters just fine but have also been told the lower levels don't work anymore. The lower levels not working does make sense as the power supply probably doesn't have enough range to lower the current at such a low LED forward voltage. It was probably designed only to deal with the various Vf's of the Lux V.