Trying to quantify mods to a Q3

[wasBlinded]

Here is how I would calculate it, Chop. The Zetex circuit is inefficient, and worse with the diode and cap added. Lets be generous and assume 70% efficiency in this setting (might be more like 65%).

Drawing 1.27 amps from the CR123, I can't imagine it is delivering more than 2.7 volts. So 2.7*1.27=3.43 watts from the battery. To the emitter, through a 70% efficient boost circuit, that is 0.70*3.43=2.4 watts. If the Vf is 3.5, then 2.4/3.5 gives a current of 0.686 amps to the emitter.

 

[Chop]

wasBlinded,

Considering a .5v drop per amp of draw, your calculations look to be right on. So, the mod only increased the current to the emitter by less than 200mA. No offense meant to anyone, but a less than 200mA increase in current to the emitter won't make a much of a noticeable difference in brightness. Most of the increase there was in brightness is likely attributable to the luxeon itself, since the stock Q3 runs at just over 500mA.

I do have to say though, 1300 lux ain't too shabby. That's on par with an Aleph II with the McR20.

 

[TrueBlue]

I have a dead stock Q3 and have avoided modding it because it worked so well.

So here are some numbers for you all to chew on from a stock Q3.

This Q3 has a SY0J emitter that puts out 680 lux through the stock sputtered reflector. To test for current draw I used BatteryStation RCR123A cells that discharged for one minute then allowed to sit for another minute. Then I took a current reading using two different DMMs. I got a current draw from 1460 to 1500mA from the cells.

The light works so good I don't know if I want to mod it. Later, I'd like to put a polished reflector in the light to see what happens.

 

[Chop]

haveblue,

Your beloved Q3 might benefit from a star transplant. If you put a T bin in there, it would probably make a noticeable difference.

 

[milkyspit]

[ QUOTE ]
Chop said:
Are you sure that you got 1300 lux on the 1X123? Did you take a current reading to the luxeon? I'm only asking because a stock Q3 runs at about 500mA. The most that we can get out of a single 123, with some pretty efficient converters, is in the neighborhood for about 700mA. Your lux reading would indicate that you are driving the luxeon at a current level in excess of 900mA. Either there is a mistake some place, or you've stumbled upon a way to get more than 700mA or so out of a single 123. Did you take a current draw reading?

I'm very interested.

[/ QUOTE ]

Chop's absolutely right about the 700mA vicinity being about the limit for 1x123. I know it's not a Q3, but for a point of reference as to pretty much the best you'd probably get out of a single 123 cell, I modded a SureFire KL1 gen4 head (the latest one, with the special long throw optic inside) to be driven with a VIP circuit (highly efficient!) at 750mA output. On a fresh 123 cell... if memory serves... that light could generate 1600 lux at one meter. Since that particular head was pretty much built for long throw AND was driving its emitter at essentially the ceiling for 1x123 current flow, I'd consider that a sort of benchmark for what can be done off a 1x123 non-rechargeable configuration... maybe a really remarkable emitter or a very large, well focused reflector could get a higher lux reading, but in general 1600 lux is probably as much as most of us could ask on a single 123! /ubbthreads/images/graemlins/ooo.gif

Chop, the stock Q3 board isn't exactly 500mA... it's a little complicated. The stock circuit outputs PFM (Pulse Frequency Modulation)... I'm no electronics guru, but in layman's terms what the circuit does is kinda sit and charge itself up from the battery with no output at all, then when enough stored energy is available in the circuit, dump it into the emitter in a quick pulse. The sense resistor determines the maximum output current, and therefore also ultimetely determines how long the circuit will be "off," waiting for enough energy, vs. "on," lighting the emitter with the specified current. The less capable the battery becomes, the longer the "off" stage becomes to gather enough juice to send that "on" pulse at the specified level of current flow, until the battery is too depleted to supply that amount of juice at all (at least not before the chip "times out") and either drops into a very dim moon mode for a low Vf emitter, or simply goes out completely for a higher Vf emitter. Unless you've got a really low Vf emitter in the Q3, this light can quite literally, and suddenly, leave you in the dark! (I've experienced it firsthand in my basement.) /ubbthreads/images/graemlins/rant.gif

Anyway, to make a long story even longer, /ubbthreads/images/graemlins/ohgeez.gif the stock Q3 comes preset to deliver a 950mA pulse, but due to the "off" times and the eye's tendency to average the on/off cycles into an average brightness, I've found a typical Q3 to be about as bright as an Arc LSH, meaning it behaves as if it's in the 350-400mA output vicinity.


Incidentally, remember, folks, that lux measures light INTENSITY, not overall output. Often a super high lux reading comes with some tradeoffs, such as an increasingly narrow beam, which may or may not be useful in the real world. At some point it kinda becomes like building a dragster to accelerate off the starting line as quickly as possible... but in so doing, you've created a special purpose vehicle that probably isn't the best choice to pickup the groceries or travel to work! /ubbthreads/images/graemlins/ooo.gif For me, the SNB ("Small-N-Bright!") lights I like to build don't get very impressive lux readings and yet are really bright for their size, mainly because these lights have broader beams that spread the photons across a wider area instead of focusing them into a narrow, lux-happy needle beam. Not making a value judgment, just pointing out the difference, and the shortcomings of a lux reading by itself as a means of comparison. Flashlightreviews.com is nice in that the lights are measured for lux AND total output... that's a far more complete picture than lux alone!
/ubbthreads/images/graemlins/thumbsup.gif

Okay, did ANYONE just follow all that? /ubbthreads/images/graemlins/icon15.gif

BTW, I'll pimp your Q3 if ya want! Been pimpin' 'em for months now, heh heh. /ubbthreads/images/graemlins/naughty.gif

 

[Chop]

OK, so that explains why my DMM is reading right at around 500mA to the LED on a 1X123 and more on a li-ion, I think. It also explains why there isn't much of a moon mode.

I suppose that the stock circuit just sucks in comparison to others that are available.

As a relative matter though, I've read reports from some saying that the stock Q3 will get ~700 lux and others saying that they are getting 1300. What's up with this?

 

[jchock]

I'm the bonehead who started all this. All I was trying to do was "quantify" what each change to a Q3 bought you in terms of lux at the center of the beam as all I'd read was "This'll give more throw..." but there were no numbers attached.

I had two modded Q3s that were fairly bright given what they were. I took readings (with appropriate disclaimers as to what I had available).

I then took amp readings. Poof. One modded Q3 dead. I'm able to resurrect it as a regular Q3. I decide to try to get the amp readings people want, I modify the second Q3 to the state the first one was in. It works, I take a reading, it draws 1.16A from a battery. I try to take an amp reading from the Lux using an inserted .1ohm resistor. Poof. That Q3 is now deader than a door nail. This time it appears to be the transistor, so I can't turn it back into a regular Q3.

I am retiring any of my efforts to get an amp reading to the LuxIII as it has now cost me my two modded lights.

(I'm a travelling graduate student, all my "spare" parts are not here. I might be able to get my spare diodes/caps tomorrow night to fix one of the Q3s, but the other is going to stay dead for a while.)

I'm not quitting playing with things, or lurking here, but someone else can risk their time and effort getting an amp reading with a modded Q3, I just !#@$! it up somehow. I transplanted the TV1J back into the "normal" Q3 and now it sputters, so things are not ok there either... And I had been using this to work up the nerve to finish gathering parts and try to play with my KL3. Now I think I'll leave it alone for a while.

As for why people get 1300 lux and not 6-700 (as it says in Flashlight reviews), I thought it was because people were running Li-Ions in the 1300 ones so that the spike in the Zetex circuit was much much higher than it normally would be (temporarily overdriving the LuxIII). I only got the 1300 after I'd changed the circuit to "maximum brightness" as per the Zetex sheet (and with helpful comments from pbarette in PMs), changed the reflector, lens, sense resistor, _and_ the Lux. From my dead Q3, I'll be able to salvage the PCB, maybe the sense resistor, the inductor, the metal ring, the two lead wires to the lux, and the Lux. I'll have to assume everything else (ZHSC300, FMTT617, diode, caps) are all dead.

 

[TrueBlue]

[ QUOTE ]
Chop said:
haveblue,

Your beloved Q3 might benefit from a star transplant. If you put a T bin in there, it would probably make a noticeable difference.

[/ QUOTE ]

My thought too! /ubbthreads/images/graemlins/grin.gif I'm going to give the light a couple more days to play with then a transplant will take place. I just happen to have 10 TWOJ emitters sitting next to me.

I'll go little steps at a time 'cause I'm a conservative and I like the little surprises!

 

[milkyspit]

Chop, I think I'm on record elsewhere on CPF as saying I hate the stock circuit! /ubbthreads/images/graemlins/icon15.gif I haven't posted very many things that strongly. However, it is a fun circuit to play with... I actually made a nifty "Milky Candle Shorty" by cobbling together some PVC pipe sections, a flame-shaped plastic cap from a dollar store Christmas candle, a 10mm LED, and the stock Q3 circuit. I swapped out the sense resistor to set the circuit for a maximal current flow of 40mA... now the little guy runs nicely off a single 123 cell for maybe 40 hours in regulation, then declining light for another dozen hours or so! /ubbthreads/images/graemlins/grin.gif

Pulses of high current (as this circuit does) present a tradeoff: one the one hand they can keep the Luxeon closer to its binned color since each pulse drives the spec'd amount of current through it; but on the other hand they're generally not as efficient as a well-designed constant current circuit. At least that's my understanding! /ubbthreads/images/graemlins/ooo.gif The trouble with the Q3 circuit is that it isn't even regulated... since the "off" duration increases as the 123 cell drains, the output gets dimmer! /ubbthreads/images/graemlins/rant.gif So basically, it offers all the downside of a high output regulator (short battery life and sudden shutdown of the light) with none of the upside (the pulsing results in effective output that's only a fraction as bright as a REAL constant current 950mA output would). /ubbthreads/images/graemlins/frown.gif

IMHO the Dorcy 1AAA LED circuit is the perfect complement to the stock Q3 circuit. Like stock, the Dorcy board is a boost circuit, not truly a regulator; however, it generates a continuous flow of output current instead of pulses... it's actually very much like dat2zip's various MadMax boards, except that the Dorcy doesn't offer as much output current as a MM+ would. Think of it a little like a ghetto MM lite! /ubbthreads/images/graemlins/grin.gif

Compated with the stock circuit, the Dorcy will deliver something on the order of TWICE the duration of bright output, plus it degrades far more gracefully... in fact, while measuring for a detailed runtime graph one evening, I fell asleep, only to wake up and find that the test light was still operational on its single 123 cell 8 hours after I'd turned it on. The output was definitely nowhere near what I'd call bright, but surprisingly (at least to me!), it was still bright enough to walk around my house without tripping or stepping on anything... and that's no easy feat since my kids usually have toys scattered in pretty much every room! /ubbthreads/images/graemlins/faint.gif Hmm... here's a runtime graph from my MilkMite mod, which should also apply to the Q3 when a Dorcy board is installed...



As far as lux readings, lots of things can affect those. What most folks forget (even most flashaholics!) is that the eyes do NOT perceive brightness in linear fashion, but rather in logarithmic fashion. In more concrete terms, that means a light pumping out 1200 lux would look only 30% brighter than one only generating 600 lux. Meanwhile, though, it cuts runtime in HALF to double that lux reading and get the extra 30% brightness... or maybe LESS than half! That's because the battery's stored capacity drops when higher current flow demands are placed on it, and the LED itself generates light less efficiently as its internal temperature rises higher and higher. Soooooo... strange as it may seem, that 1300 lux monster might only look marginally brighter than the 700 lux Q3.

But wait, there's more! (Sounds like a Ginsu knife commercial!) /ubbthreads/images/graemlins/yellowlaugh.gif Since lux measures beam intensity rather than total output, lots of other things can influence it. Here's a partial list... a smooth reflector reads higher lux than an orange peel one, even if the total output of both is identical... a reflector that more aggressively focuses into a narrow beam will have a higher lux reading... a UCL will give a higher lux reading than a polycarbonate lens, both because it passes more light and because the plastic itself probably diffuses the light passing through it a teensy bit... the list goes on and on. Also, the same light will give a higher lux reading when it's first turned of than it will later, when the emitter's grown warmer! There are probably lots more things to take into account.

Ufokillerz and I compared a bunch of stock SureFire L4 flashlights about a year ago... the dimmest read around 600 lux, and I think the highest might have approached 1000 lux! But the bright one in reality only looked a little brighter... the difference was clearest when holding one L4 in each hand and alternately turning each one on and off. We've gotta make sure we keep the real world goals in sight (no pun intended), and don't get caught up in the numbers! /ubbthreads/images/graemlins/icon15.gif

Jchock, you ain't no bonehead, my friend. /ubbthreads/images/graemlins/wink.gif I'm not so sure it's easy to quantify what each change does for lux in an absolute sense, because everything will vary from light to light, part to part. However, if you're looking for biggest bang for the buck ranked roughly from best to worst, that we can probably do! I'd make one list that doesn't affect battery life, and a second list that does. Here are some examples that maybe others could build on...

Lux-Boosting Mods that Don't Affect Battery Life

1. Switch to a smooth reflector
2. Install an emitter with a higher-binned flux (meaning it'll be brighter with the same input current)
3. Replace the polycarbonate lens with a UCL (an ultra clear glass lens... lets more light pass through)
4. Improve the heatsinking to keep the LED cooler

Lux-Boosting Mods that DO Affect Battery Life

1. Install a more efficient boost circuit!
2. Increase the maximum current flow setting, up to the limits of the battery (and even then, keep going with a Li-ion rechargeable instead of a single-use 123 cell)

 

[TrueBlue]

My Q3 with an SYOJ emitter doesn't even come close to running 90 minutes. I finished a runtime a couple of minutes ago. With a fresh rechargeable CR123A with 650mA capacity I got a runtime until empty of 33 minutes. If you do the numbers then my Nuwai is running a average of 1182mAh...almost 1.2A.

The Q3 is brighter than my stock Longbow with a Lux I and Longbow with a Downboy 1000 and a TXOJ emitter. Both of those are also running single RCR123A cells.

Runtime I don't have a lot of but brightness...yes! I don't want to bump up the current anymore. The light is too cheap to put an expensive drop-in for it but I might just whip into the Q3 some electronics from an Xnova AA light. There is plenty of room to do that. The Xnova electronics run 800mA on 3.7 volts and would give me a longer runtime of around 50 minutes. I'll try a TWOJ emitter in the light first and run a test before I decide if I'm going to pull the electronics out.

 

[Chop]

Scott,

I can't remember who it was that I was talking to the week before last, but I was telling him that I'd love the be a fly on the wall in your shop. The stuff you mess with is pretty cool. The "candle" is killer.

Jchock,

You wouldn't believe how many Surefires I've buried. A long while back CM and I were on this kick with the A2. We just had to get at the circuit. Well, needless to say that we ripped a few very expensive lights apart and got nothing out of it. It was fun though.

The point I'm making is that you shouldn't let your screw ups deter you. It's obvious that you have at least some expertise in the field. Keep running with it.

As for your dead Q3, PM me with your address. I'll send you my circuit. Just send it back to me if/when you are able to repair yours.

 

[milkyspit]

[ QUOTE ]
haveblue said:
My Q3 with an SYOJ emitter doesn't even come close to running 90 minutes. I finished a runtime a couple of minutes ago. With a fresh rechargeable CR123A with 650mA capacity I got a runtime until empty of 33 minutes.

[/ QUOTE ]

Haveblue, are you referring to 90 minutes based on the graph I posted? Sorry, I lost where you were getting that number from. Probably a dumb mistake on my part! /ubbthreads/images/graemlins/banghead.gif

Anyway, my graph is valid for a Q3 only if the stock circuit has been replaced with a Dorcy 1AAA circuit. In addition, there are a couple tweaks I make to the Dorcy circuit for a little better efficiency. The graph most definitely does NOT show what the stock circuit will do! In fact, the tweaked Dorcy circuit pretty much DOUBLES the runtime over stock. /ubbthreads/images/graemlins/ooo.gif

Also, I was using a regular 123 cell, not a rechargeable one.

Chop, thanks. /ubbthreads/images/graemlins/grinser2.gif /ubbthreads/images/graemlins/blush.gif /ubbthreads/images/graemlins/bowdown.gif

Actually, I owe you a reply to a PM you sent a week or two ago... I haven't forgotten! Now I may FINALLY have the time to respond, and have some ideas worth mentioning. /ubbthreads/images/graemlins/wink.gif

BTW, if you were a fly on the wall in my shop, you might get "X-ed!" /ubbthreads/images/graemlins/faint.gif (MR-X flashlight: X3T emitter driven with 1.5A output current, in full regulation for over an hour, built by Hotbeam and Burnt_Retinas, Aussie modders extraordinaire.) Look over here for an explanation.

Yup, must be a mad scientist. /ubbthreads/images/graemlins/duh2.gif

 

[TrueBlue]

Naw, I did my own runtime last night and graphed it. My light loves to suck up power. I think some of the power is being sucked up generously by the inefficient converter.

 

[jchock]

Oh, buried SFs, that's got to be harsh. I hope I don't end up doing that with mine, I can't afford to replace them at current prices. Q3s are a different matter. Sort of.

I would like to be able to get the Lux amp readings, but something is telling me that I'm not meant to get lux readings with the Q3 unless I buy a bench power supply and some other goodies. That's not really where I can go right now (or justify)... And the "I like to collect cool tools" excuse will only go so far with the wife.

Well, my Q3 is dead. I hope to ressurect it. I've been in contact with pbarette who seems to have a specialty in the Zetex circuits, and he's going to send me a couple spare small parts. With the spares, maybe I'll jump in and try yet again (Do I learn? Maybe I don't. I'd like to think I do...), but first I'd like to get the dead one working again. Thanks for the offer of your circuit though.

 

[jchock]

Well, I got my spare capacitors and diodes... I go to reinstall them in the restored Q3 that worked (and installed a TWOJ obtained from B/S/T) and it works, and registers about 1300lux again. I also tried fixing the dead one where I thought the transistor might be dead.

pbarette told me that if the lux becomes disconnected while on, the entire voltage load runs through the Kemet tantalum capacitor and that can fry (if it doesn't I guess you can fry the transistor as well). BOTH capacitors from the fried state read as shorts on the continuity setting of my RadioShack DVM. Replacing the one capacitor on the "dead-as-a-doornail" Q3 restored it to functioning ability.

SO, if you have a circuit modded Q3 with output caps and diode, and you're trying to read the output amperage to the Lux and temporarily cause the load to be entirely carried by the capacitor, the capacitor fries and becomes a short across the Lux instead...

Also, WRT runtime, I'm getting something pretty low. No moon mode or anything, it just doesn't turn on. I think I ran it for a walk outside (about 20min) and a bunch of on/off inside (call it 10-15min worth). After that, it just wouldn't turn on. It might run, then you turn it off, and try to turn it back on... nope. I guess it doesn't have enough to run the circuit to turn the Lux back on. Not sure what to do about that...

Maybe if I fry another one (again... ugh...) I could just take the components off the board and use the board as a battery connection to a NexGen board... (I intend to get a couple of 3rd Shift's Luxless ones for use with the Luxes I've transplanted as part of these mods... maybe one of those will get fried as well. No, I'm not hoping that happens...)

 

[jchock]

Taking advantage of the luxless 3rd Shift Lights, I looked at the circuit. The ones I got from 3rd Shift use the ZHSC310 IC, not the 300. Also there are two extra capacitors, one on across the battery, the other across the lux. They're small chip ones and they look just like the 2.2uF ones I bought for my other mods but looks don't mean anything...

Anyway, using these I threw them on the lux meter (updated the first post)

factory (Z310 circuit), SX1K Lux3, factory reflector/lens: 370-400lux/1m
Z310 Q3, removed capacitors, TV1J Lux3, factory reflector/lens, factory R020 sense resistor R020: 430 lux/1m
Z310 Q3, removed capacitors, TV1J Lux3, factory reflector/lens, sense resistor R020 with .033ohm in parallel: 530 lux/1m
Z310 Q3, removed capacitors, TV1J Lux3, IMS reflector, 22.6mm UCL, sense resistor R020 with .033ohm in parallel: 900 lux/1m

Not quite sure why the TV1J made so little difference though.

 

[milkyspit]

jchock, I'm enjoying reading about all your Q3 variations, and the test measurements are great! /ubbthreads/images/graemlins/grin.gif Keep up the good work.
/ubbthreads/images/graemlins/thumbsup.gif

On the question about why the TV1J didn't help more, think I can explain that. The capacitors help provide more of a constant current flow to the Lux3... without them, the Lux3 receives pulses of current, but our eyes average the light and dark periods and the output looks dimmer. When you swapped the SX1K for a TV1J, you also removed the capacitors, which sacrificed most of the additional brightness you should have received. If you were to add the capacitors again, my guess is that you'd probably get the additional brightness you were expecting! /ubbthreads/images/graemlins/smile.gif

 

[ICUDoc]

Hi all,

Thanks a lot- I have learned a lot from this thread.

 

[jchock]

OK, so leaving the caps in... interesting. I'll have to transplant the TV1J now... /ubbthreads/images/graemlins/smile.gif The final TV1J light will go to my BIL and he wants to know if I own something I haven't "****ed with..." What is the fun in keeping something stock?

In any case, I also PM'd pbarette about the new board and the caps, he suggested removing the output cap as without the output schottkey diode, it won't help the circut. The input cap (he suggested) will lower the load from the battery so it'll provide "cleaner/smoother" current, but will also cut down on the circuit efficiency. Maybe I'll transplant the Lux, take a reading, and pull the output cap, and take a reading... The things I do...

Oh, these new luxless Q3s from 3rd Shift all came with a retaining ring. The interior is threaded. The ring has to be removed to allow the use of the IMS, but there is a ring of copper as a spring to connect the board to the body. The copper rings are all thinner than the ones that came without the retaining ring. They almost need the ring to hold the lux/board down or the light won't turn on. There might need to be a thicker O-ring around the lens to compensate. Either that or find some way to cut three or so gaps in the plastic retaining ring to make room (enter Mr. Dremel).

OTOH... this means that I don't need to hold the reflector down to the lux to get a reading if I had a long axial .1ohm resistor on the lux. This frees a hand and makes it more likely that I'll get a reading with less trouble. This reading may have to wait as I'd have to add that to a digikey order...

OH, I made a two stage switch mod with a 10 ohm 1/4 watt ceramic resistor (the "old" traditional kind with a color band and everything.). I need to turn the cap out about 3/4 of a turn but it works fine. If you solder to the original spring and across the coils, you'll stop the spring coils from moving, essentially creating a ring of the original diameter. This makes it harder to squeeze into the original clear plastic base. Just something to keep in mind for those of you...

Anyway, this particular TWOJ (ZHSC300 IC) Q3 gave 1250lux at 1m in high mode on that battery. In low mode it gives 40lux at 1m.

 

[milkyspit]

Very nice lux readings! 1250 lux is a righteous amount of throw for a little light, and 40 lux is much more than something like an Infinity Ultra... yet it's still way dimmer than the high beam, making for good contrast between the two settings. Also, your battery ought to run for quite a while on the low setting even though the resistor really hurts efficiency. Despite the resistor, my guess is you'll see something like 15 hours of gradually decreasing brightness from the low beam. Works for me! /ubbthreads/images/graemlins/grin.gif

Awesome! /ubbthreads/images/graemlins/bowdown.gif