Flat regulation chart on Zpower from DX

The flat regulation chart on this Zpower from DX looks amazing. Does anybody already have one. I don't, so I don't know how good or bad it is. http://www.dealextreme.com/details.dx/sku.1322

Nice regulation. I wonder how the light would work with a protected 17670 cell, since they say that 18650's don't physically fit.

I have to be a little skeptical on the flat run-time graph that DE posted
on their website. They are trying to convince their customers who ordered
the DX Cree light to switch to the MTE light as their DX Cree supplier is
evidently having problems with the on-board current regulator. They include
the statement: "Regulated" effect (MTE did not confirm this feature but the
effect did show in the tests), which seems strange since if a light was indeed
regulated, one would think that the manufacturer would advertise it.

George

adirondackdestroyer said:

Nice regulation. I wonder how the light would work with a protected 17670 cell, since they say that 18650's don't physically fit.

Click to expand...

What I suspect is that you'd see a similar curve as the DX Cree light -- flat regulation for the first several minutes of runtime, then gradually declining (direct drive) after that. At first the battery pack will have a voltage of about 4.2, and the buck circuit will reduce that to a regulated 3.6 Afterward, the battery voltage would likely sag and output would be reduced since buck circuits can only reduce the voltage.

Since the ZPower is starting with 7.2 volts, even as the voltage sags, the buck circuit will still be able to reduce it to 3.6 no problem, until it's pushing time to change the batteries anyway.

DX seems to be quite reputable. I would believe what they said until proven otherwise. They seem to value their reputation.
Mike

I ordered the DX 3W Cree on last friday, but DX proposed to change my order for the Z-Power. I accepted the exchange. I don't like its inability to use 18650, but well, will see how it performs.

glire said:

I ordered the DX 3W Cree on last friday, but DX proposed to change my order for the Z-Power. I accepted the exchange. I don't like its inability to use 18650, but well, will see how it performs.

Click to expand...

Well if you don't like it, you can always sell it onto me, at a huge discount of course !!

Just received a confirmation of the MTE shipping

vetkaw63 said:

DX seems to be quite reputable. I would believe what they said until proven otherwise. They seem to value their reputation.
Mike

Click to expand...

I think you are right. It will be easy to see if these results can be replicated. The equipment is fairly inexpensive. You just test the light with a lux meter that is hooked up to a PC. They have programs now that will make the chart for you.

Even cheaper testing is doing bounce off a ceiling in a smallish room and measuring light output with a lightmeter. Just monitor closely and plot readings. Works for me when I test regulated or unregulated led, and incan lights. BTW that flat graph looks like a perfect example of a buck circuit. Sort of like my KL6 with Cree, only shorter runtime with 2 RCR123's, with 1amp to led.

Bill

Bullzeyebill said:

BTW that flat graph looks like a perfect example of a buck circuit.

Click to expand...

It could also be that the graph was made with only 3 data points.

chevrofreak said:

It could also be that the graph was made with only 3 data points.

Click to expand...

Good call. I'd hope that's not the case and have more faith in kyle than that, but the theory fits the facts.

chevrofreak said:

It could also be that the graph was made with only 3 data points.

Click to expand...

Seems unlikely as the Ultrafire WF-501B Cree CR123A 18650 Flashlight
$24.95

on
http://www.dealextreme.com/details.dx/sku.1315

has 7 data points

as does the DX 3W Cree 18650 CR123A Flashlight
$26.95

on
http://www.dealextreme.com/details.dx/sku.1284

probably just well regulated.

Even if it is 3 points, still show flat discharge.

I have an abundance of 17670s so will be interested to see if the ZPOWER plays nice with them.

If it's expecting ~7.2V I wonder how the regulation would be affected?

Do 17670's fit in the DSD charger?

martonic said:

Do 17670's fit in the DSD charger?

Click to expand...

Yes, they do fit...I'm using the DSD to charge the 17670's I use in my Gladius

I have a bundle of mostly functioning 18500s and 17670s liberated from laptop battery packs. Unfortunately I have no flashlights that can use them at present... wah!
Most upsetting

Received a package from DX yesterday... but it only contained batteries and a charger... no light :'(

Anyone played with the ZPower yet? Haven't heard anything

I will be going to the post office to pick up mine in about an hour or so

Got some nice freshly charged LIR3.6V with me for testing

*pictures myself savaging the package in post office and loading 'er up, to the bewildered stares of postal workers*

*whimpers*

Due to unforseen circumstances I did not get to the post office. I even left work early... (does this mean I have a problem? ) but nonetheless, events out of my control mean I will have to wait till Monday.

Oh well, I'll just play with my sexy little fenix.

Yes, I got it yesterday
I couldn't test it immediatly as the batteries I took with are too big (some protected 16340 that are 3-4mm longer than expected, should be called 16380 :thumbsdow).
I tried in the evening with some old AW's protected 16340, still 0.5mm too long but I could close partially the tailcap.

The light has two levels of brightness. Not obvious to distinguish them, I would subjectively say about 10-15% difference. Sequence is low-off-high-off and it's done on the tailcap, not by the circuit.
On low the throw is similar to the Streamlight 4xAA PP Lux and the CPF's VB16 (I have the 3W version). On high the MTE beats them easily (the difference is much more visible outdoor than indoor). The MTE has also a great spill, the 4xAA PP Lux looks anemic in comparison.

I mesured the current. About 0.72A with two 16340 (7.2V), 0.11A with only one (3.7V). As a comparison, my CPF's VB16 takes 0.7A from one 18650 (3.7V) and 0.5A from two 16340 (7.2V).
18650 don't fit in the MTE. Maybe 17670 don't either, but it would be useless, unless you want long runtime and about 1x AAA light brightness (say, similar to Fenix L0P).
I doubt it's regulated, or maybe it needs an input voltage >4.5V to be regulated. In any case not a good buck circuit IMO.

Other things noted.
It's well constructed, reflector and window look clean, but they're plastic. Head is not sealed.
Body is too short IMO has the tailcap can't be closed completely with 16340 slightly out of spec.

I'll try to post some beamshots next week (I'm off this WE).