Run-Time Plot - TerraLUX MiniStar2

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Roy

Roy

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This runtime plot is for a TerraLUX MiniStar2 LED conversion for the AA MiniMag. The drop-in converter uses a side emmiting LS LED. Two Everactive AA alkalined batteries were used.

Equipment used is a Extech Mdl 401021 Light Adapter intoa Radio Shack 22-805 multimeter with a PC interface that is using Scopeview software (V1.08).

The vertical axis is in 30 mV per division and is equivalent to 30 Fc @ 1 Ft.. The horizontal axis is 30 minutes per division.

Be aware that your actual battery mileage may vary from that indicated by this runtime plot.

ministar.jpg
 
Hello Roy,

What did you think of the beam quality?

I see yours was a SE also. I wonder why their web page shows something different...

Tom
 
Roy, is this as bright as the Mcgizmo L1 mod on high....If I am reading the chart right, it starts out brighter, then stays fairly close to the L1 for a good long time...
 
The calibration of my light meter is 1 mV = 1 Fc so 1vDC = 1000 mV = 1,000 Fc. The L1 on hi started at 1,500 Fc and the MiniStar2 started at 195 Fc.
 
McGizmo Hi setting L1 = 1,500fc = 16140 lux

MiniStar2 195 Fc = 2098.2 lux

So the L1 is 77 times brighter than the MiniStar2

Looks like the MiniStar is highly underpowering the Luxeon, so thats how they managed the thermals....

This would imply that a 5mm Nichia would be brighter than a TerraLux....

Ah, and the 5 hour runtime is another indication of being under driven.
 
NewBie, the McGizmo L1 on high output is about 7.7 times the output of the TerraLUX MiniStar2.

The Lux figures you mention are too high. Looks like they should be divided by 10 at least. /ubbthreads/images/graemlins/smile.gif

Britt
 
As I understand the relationship of Fc <> LUX, it goes like this:

One Footcandle (Fc) at one foot is equivalent (equal) one LUX at one meter.

All of my measurments are at one foot and the "@ 1 Foot" is implied.
 
Same here, Roy. /ubbthreads/images/graemlins/smile.gif

So, for the McGizmo L1 on high roughly 1500 Lux and for the TerraLUX MiniStar2 about 195 Lux?
 
Maybe someone can try modding it to run at a higher current. It's such a cheap mod, if there was a way to increase it's output....

Any pictures of the backside? Maybe there are some clues as to how it's driven and how easily it might be modified.
 
Hello Utomatoe,

The problem with pushing more current through it is that you need some kind of heat sink. The MiniStar2 seems to be lacking a robust heat sink.

Tom
 
[ QUOTE ]
BC0311 said:
NewBie, the McGizmo L1 on high output is about 7.7 times the output of the TerraLUX MiniStar2.
Britt

[/ QUOTE ]

Oops, missed a decimal point, good catch. Still dismal! (personally I'd be ashamed with that product)


[ QUOTE ]
BC0311 said:
The Lux figures you mention are too high. Looks like they should be divided by 10 at least. /ubbthreads/images/graemlins/smile.gif

Britt

[/ QUOTE ]

Nope, you are most definitely wrong.

10.76 Lux = 1 footCandle
1 Lux = 0.0929 footCandle

So, 195 footCandle * 10.76 (conversion factor for lux to fC) = 2098.2 Lux

Roy, here is a quick calculator for you:
http://www.radimg.com/ref_unit_calc.htm
 
[ QUOTE ]
SilverFox said:
The problem with pushing more current through it is that you need some kind of heat sink. The MiniStar2 seems to be lacking a robust heat sink.


[/ QUOTE ]

Well along with modding the module to overdrive it, an innovative heatsink is required as well... of course there isn't much space to work with unfortunately...
 
It seems to me that the bat.is flat dead at 5 hrs. period and there is no residual "moon mode" at all..Hum. /ubbthreads/images/graemlins/thinking.gif
 
Hello utomatoe,
I think there is no need to increase the drive current because ROY has just show his run time plot and TerraLUX MiniStar2's battery looks dead flat on 5 hrs. runtime without any residual "moon mode" at all. /ubbthreads/images/graemlins/thinking.gif
 
Hello NewBie,

Just to make sure that everyone understands your fc to lux conversion, let me add the following:

1 fc (at 1 foot) = 1 lux (at 1 meter) = candela
1 fc (at 1 foot) = 10.76 lux (at 1 foot)
1 lux (at 1 meter) = 0.0929 fc (at 1 meter)

and the base equation
candela = fc * distance in feet squared
candela = lux * distance in meters squared

Your conversion is correct as long as you add the proper distance units.

195 fc (at 1 foot) = 2098.2 lux (at 1 foot)

However Roy and BCO311 are also right in saying 195 fc (at 1 foot) = 195 lux (at 1 meter).

The reason this distinction is important comes into play when you are evaluating the throw of the beam. The throw down to 1 fc or 1 lux is the square root of the candela reading.

If I am interested in the distance down to 1 fc, then the square root of 195 is about 14. At 14 feet, the light drops off to 1 fc.

If I am interested in the distance down to 1 lux, then the square root of 195 is about 14, but since our reading is metric, the distance is 14 meters. At 14 meters the light drops off to 1 lux.

At a casual glance, the statement that the light puts out 2098 lux initially makes me think this is a very powerful light that will reach out almost 46 meters. After more careful reading, I understand that we are dealing with conversions.

I believe it would have been clearer just to point out that one light puts out 1500 fc and the other one 195 fc, and it appears that the 1500 fc light is 7.7 times as bright as the 195 fc light.

Tom
 
Tom and Roy, thanks for making this clear. /ubbthreads/images/graemlins/ohgeez.gif

I am impressed with the MiniStar2's runtime. Please correct me if I'm reading the plot wrong. After the initial drop during the first 45 minutes, it only declines about 50 fc (at one foot /ubbthreads/images/graemlins/grin.gif) over the next 4 hours and 15 minutes.

That looks like good, long and steady output to me.

Britt
 
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