E2e's with underdriven 5 watts - Twins: SE & HD (beam Comparisons)

[Termac]

Re: E2e\'s with underdriven 5 watts - Twins: SE & HD (beam Comparisons)

A simple extension for the E2x, should be more economical, and yet do everything except perhaps host the ARC head. And it could have a couple advantages. For one, it could be finned to participate in thermal management. Also, when you don't want the length, you can pocket the adaptor, all without the bother of dummy cells.

 

[McGizmo]

Re: E2e\'s with underdriven 5 watts - Twins: SE & HD (beam Comparisons)

Doug,
No problem. CPF "Group" efforts spread the fun!

- Don

EDIT: I see Wayne has mentioned the wizard. If this driver was used in the Ex mods, the UHB and virtually any battery combo you want to throw at the module would be fine! That Wayne!! In fact, I might have even tried an Ex module with a proto E3e and found it outstanding ........ or was that another dumb dream

 

[DSpeck]

Re: E2e\'s with underdriven 5 watts - Twins: SE & HD (beam Comparisons)

Actually, Termac, some people have asked for this kind of extension for the UBH. If you want one, let me know what size you will need it, and I can make it. If you order before I send the batch in for anodizing, you can get it anodized too. You can email me at [email protected] to work out the details.

Don, the Wizard from Wayne

sounds like it's going to be exactly what is needed for the 5W mods. I really like the underdriven one you've come up with here, too - I just wish there was a source of cheaper suitable aluminum reflectors than Surefire...This mod is something I'd like to pursue as well, but the funding isn't easy...

 

[Termac]

Re: E2e\'s with underdriven 5 watts - Twins: SE & HD (beam Comparisons)

 

[brightnorm]

Re: E2e\'s with underdriven 5 watts - Twins: SE & HD (beam Comparisons)

 

[Glow Bug]

Re: E2e\'s with underdriven 5 watts - Twins: SE & HD (beam Comparisons)

Originally posted by McGizmo:
Luminance,

I forsee a dropin module consisting of 1W and 5W (underdriven) LED's, both HD and SE. The 1W low domes will not yield a useful beam in the Ex reflectors. There is a slight modification required of the Ex head but this can be accomplished with a hand drill and vise. One comment if someone decides to do this; Have a vacuum running and sucking up the dust and chips as you drill. If the reflector gets dusty, you don't want to wipe it down with anything by sticking a cloth in through the hole.

Dat2zip and I are going to explore making the LED modules and possibly selling completed flashlights in his sandwich shop. This would likely be the case of making a few when we have the time and then Wayne posting them for sale. We are still in the R&D stages and need to see if we can come up with something that would be reasonably cost effective. A SureFire E2e or E1e is not an inexpensive light to start with.

I don't have any 1W SE whites to test but I suspect that they might be favorable in the Ex reflector. I have a 1W HD white in the Ex reflector and I like the beam pattern but it will not throw as far as the center hot spot of the collimator. There is no comparison in overall quality and even distribution of the light; the stippled reflectors are awesome.

- Don

<font size="2" face="Verdana, Arial">Is this still in the plans?

 

[McGizmo]

Re: E2e\'s with underdriven 5 watts - Twins: SE & HD (beam Comparisons)

GloBug,

The short answer is probably not. Wayne is up to his you know what in you know what in trying to keep the BadBoys available as is and the McLux program has taken more resources in terms of cash as well as time than we ever expected. Money can be borrowed if needed but I can't seem to find a credit card that will allow you to get more time!

When time has permitted, I have made a few of these but they found homes immediately. Perhaps in a few months when the work is done on the McLux program and we have seen what the professional offerings will be for the year (SHOT show), this idea may be revisited. I have some similar ideas in mind that would utilize the host less E(x)e bezels out there but am not at liberty to discuss these ideas at present.

- Don

 

[Entropy]

Re: E2e\'s with underdriven 5 watts - Twins: SE & HD (beam Comparisons)

Originally posted by McGizmo:
Luminance,

Dat2zip and I are going to explore making the LED modules and possibly selling completed flashlights in his sandwich shop. This would likely be the case of making a few when we have the time and then Wayne posting them for sale. We are still in the R&D stages and need to see if we can come up with something that would be reasonably cost effective. A SureFire E2e or E1e is not an inexpensive light to start with.

- Don

<font size="2" face="Verdana, Arial">McGizmo, be wary of floods of drool...

Do you think that a MiniMag could handle an underdriven 5W? (Maybe a 5W cyan with a BB400 or 500 - Probably the 400 is safer in a MiniMag.)

 

[McGizmo]

Re: E2e\'s with underdriven 5 watts - Twins: SE & HD (beam Comparisons)

Entropy,

As I recall (memory is suspect) Wayne Y. commented recently in another thread that 2 cells is NOT enough to power a 5W. Your Vin is too low to my understanding. I also expect the thermal path as well as thermal mass in the mag AA is too little but for short bursts with a 5W, even if you put some combo of batteries in the tube to get the voltage up. I am no expert on this at all but if you want a brighter light in the mag aa host, I would consider trying a 1W with a 750 BB. This is pure speculation here and hopefully others with more hands on experience can point out that I'm all wet or possibly am suffering from cranial-rectal insertion syndrome (CRIS) *

- Don

* Hey, where do you think crisis came from?

( OK, maybe I made that up too, sheesh)

 

[monanza]

Re: E2e\'s with underdriven 5 watts - Twins: SE & HD (beam Comparisons)

With a 400 BB one should be able to go all the way down to 2.3-2.5V or so for Vin. NimH will probably not work very well but alks or liths should do it.

Cheers.

Edit - I assumed an efficiency of .75-.80 and a Vf of 6.5-7V for the 5W LS with a critical input current of 1.5A.

 

[doubleganger]

Re: E2e\'s with underdriven 5 watts - Twins: SE & HD (beam Comparisons)

I get about 2 1/2 hours on my badboy 400 before it starts to dim using 1800 mah nimh batteries

 

[monanza]

Re: E2e\'s with underdriven 5 watts - Twins: SE & HD (beam Comparisons)

doubleganger, that sounds like runtime for a 1W not 5W LS.

Cheers.

 

[doubleganger]

Re: E2e\'s with underdriven 5 watts - Twins: SE & HD (beam Comparisons)

sorry, wasn't paying attention

 

[Jonathan]

Re: E2e\'s with underdriven 5 watts - Twins: SE & HD (beam Comparisons)

Actually, with a boost converter, both the input voltage and the output voltage affect things, not just the input current.

The way the boost converter works, you have an inductor from your input that is switched to ground by the transistor. The current ramps up in the inductor. Then the transistor opens, and this current is delivered at a higher voltage to the output. The nifty trick is that the voltage boost provided by the inductor, and thus the _energy_ stored in the inductor, is placed in series, and is added to, the supply.

This means that if the supply voltage is very near to the output voltage, then the transistor only has to carry current for brief instants.

Neglecting losses, the switching element for a boost converter is on for 1-(Vin/Vout).

-Jon

 

[carl]

Re: E2e\'s with underdriven 5 watts - Twins: SE & HD (beam Comparisons)

You guys are doing a great Job! And without having to make an elongated head like the KL1. Why does the KL1 need to be longer while you guys can keep the same dimensions? I like it!

 

[Entropy]

Re: E2e\'s with underdriven 5 watts - Twins: SE & HD (beam Comparisons)

Originally posted by McGizmo:
Entropy,

As I recall (memory is suspect) Wayne Y. commented recently in another thread that 2 cells is NOT enough to power a 5W. Your Vin is too low to my understanding. I also expect the thermal path as well as thermal mass in the mag AA is too little but for short bursts with a 5W, even if you put some combo of batteries in the tube to get the voltage up. I am no expert on this at all but if you want a brighter light in the mag aa host, I would consider trying a 1W with a 750 BB. This is pure speculation here and hopefully others with more hands on experience can point out that I'm all wet or possibly am suffering from cranial-rectal insertion syndrome (CRIS) *

- Don

* Hey, where do you think crisis came from?

( OK, maybe I made that up too, sheesh)

<font size="2" face="Verdana, Arial">Wayne didn't specifically say exactly why, but I replied that I suspect that the limit isn't actually voltage, but current.

Specifically, the switching transistor in the converter must handle the input and not the output current of the regulator. The current requirements of a 5W LS driven at full spec (700 mA, approx. 6.5V) requires an input current from a 3V supply over 1.5 amps. (Conservation of energy - Input power times efficiency must equal output power.)

But an underdriven 5W LS (driven, say, at 400 mA) would only require 800-1000 mA input.

I suspect that an underdriven 5W operating around 2W would be slightly better at dissipating heat than an overdriven 1W running at 2W - While the packages are almost the same outside, inside the 5W has 4x the die size to dissipate heat from. The question is whether the 2AA MiniMag body can dissipate that heat.

Edit: The Brinkmann 2AA can handle a 5W underdriven at 2.1W - See http://www.candlepowerforums.com/cgi-bin/ultimatebb.cgi?ubb=get_topic;f=14;t=001002#000000

But that's not with a BadBoy converter.

 

[McGizmo]

Re: E2e\'s with underdriven 5 watts - Twins: SE & HD (beam Comparisons)

Originally posted by carl:
............. Why does the KL1 need to be longer while you guys can keep the same dimensions? .........

<font size="2" face="Verdana, Arial">Carl,

There are a few reasons why the KL1 is a longer head. The collimator requires more length in front of the LED than the reflector does. The KL1 also hosts a buck/boost circuit which consists of more components and requires more volume to house it. The emitter board/ heat sink is a seperate bulkhead, without any additional components. The KL1 is a very well designed part, IMHO, and is not wasting any space.

- Don

 

[carl]

Re: E2e\'s with underdriven 5 watts - Twins: SE & HD (beam Comparisons)

Thanks Don, now I feel better about the KL1. I guess the buck-boost circuitry is to allow the flexibility of 3-9V input?

 

[Entropy]

Re: E2e\'s with underdriven 5 watts - Twins: SE & HD (beam Comparisons)

Originally posted by Jonathan:


Neglecting losses, the switching element for a boost converter is on for 1-(Vin/Vout).

-Jon

<font size="2" face="Verdana, Arial">Correct. So ideally, assuming the converter is operating in continuous mode (i.e. inductor current is always forward and never drops to zero), the duty cycle for driving a 5W LS is around 60%. High, but not unreasonable. Of course, that calculation is assuming a resistive load. An LED behaves very differently. With an LED, no matter what the duty cycle is, the voltage will rise up to Vf.

The reason a boost converter works is because inductors resist change to the current passing through them. When the transistor switches on, the current through the inductor ramps upward. Ideally, it will do this forever, but in reality the resistance of the power supply and of the transistor will stop this from happening. But when the circuit is opened (transistor switches off), the current wants to continue to flow. Ideally, opening a circuit with an inductor carrying current through it will result in an infinite voltage. (In reality, this never happens., due to imperfect inductors or a transistor that can't stand the voltage drop across it that results from such abuse.)

In the case of an LED, the voltage will rise until the current through the inductor can go somewhere. (i.e. Vf of the LED).

A BadBoy circuit can drive an output to the 7v or so required to light up a 5W LS. Whether it can do this AND supply full rated current is a different story. (From the looks of it, it CAN, but the switching transistor in the IC can't handle that much current for very long before forcing the regulator into thermal shutdown, see dat2zip's post at http://www.candlepowerforums.com/cgi-bin/ultimatebb.cgi?ubb=get_topic;f=14;t=000444;p=16 )

At a lower output current, the BB might be able to handle the task.