Run-Time Plot - MagmaLED-AA

[Roy]

This runtime plot is for a AA Minimag with a Technology Associates MagmaLED modification. This is a single LED conversion of a AA Minimag. At the end of 40 hours it was still generating enough light to see your feet with.

Equipment used is a photocell and a Radio Shack 22-805 multimeter with a PC interface that is using ScopeView software (V. 1.08).

The vertical axis in in mA and the horozontal axis is 30 minutes per division. To conserve space, five screens were superimposed over each other to create one plot.

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

 

[Tater Rocket]

Wow, that is pretty nice regulation. 30 hours or so to half brightness (that is what I usually go by). They need to figure out a way to get them a bit cheaper though. I think $10 or so would be the magic number to get me to buy one. Well, probably not as I have two minimags with opalecs in them anyway, don't particularly need a single LED light that large.

Spud

 

[Atrick-Pay]

Roy: Two questions, Is this as bright as a Arc-AAA? or a Photon2?

Second question what is 6 X 9?

 

[Roy]

My project for this weekend is to see what it will take to make it work reliably in a AAA Minimag. It works in some but stuck in mine. I think a little polishing of the edge of the circuit board with some emory cloth might get it to work in the AAA. We shall see.

ADDED:

So much for that projedt! Broke one of the leads off of the circuit board and am unable to solder it back on!

 

[Roy]

Answer to the first question;

No, it's nowhere as bright as an incasadent(sp) bulb and I have no idea about a Photon.

Although I never meant for the runtime plots to measure brightness ( too many factors I have no controll of and or knowledge of), since all but one of the plots (ARC AAA UV) were measured at the same distance, a relative compairison of brightness can be made. On the righthand side of the plot report there is a value for Max measurment and Min measurment. Compairing Max values should give you a relative measurment. Look in the Runtime Archives for those numbers. Doug generally updates the archives every weekend.

http://thelightsite.cruxial.com/reviews/runtimes_archive/runtimes.html

Question two:

All I remember from "Hitchhikers Guide..." was the search for the meaning of Life etc.... Looked it up on Google and got the answer!

 

[Atrick-Pay]

Roy: Thanks for the answers.
I know your not going for the "which is brighter"
thing (Which I think is good) But I'm
still looking for a bed-side light and just wondered if this mite be about the right
brightness, The Infinity came close but the
light was to small for my needs

Since you had one I thought I would ask you.

Don't Panic

 

[Charles Bradshaw]

The current measurement, as Roy stated several times before, is from the photo receptor, not the light's batteries! His plots are about how long the thing puts out light for a given type of battery.

The relative part of this, is that in the runtime plot, you can see how the light level drops over time.

It is in NO way an objective light level measurement, nor is it intended to be. Roy has no way to conveniently measure the current in each light he does a runtime for. So he came up with this, to let us know how long batteries last for each one he tests, and the cutoff point of 'enough light to see your feet', unless his OS crashes on him during the test run.

This show the battery discharge curve, using light output to a photocell and measuring the current generated by that. It is indirect, but useful to see how the batteries hold up in a given light or module, as in this case.

 

[Roy]

Take a look at the runtime plot for the ARC AAA IR flashlightl
http://thelightsite.cruxial.com/reviews/runtimes_archive/frameset.html
Notice that it shows a pretty good runtime! There is one odd thing about the plot...the flashlight puts out NO visable light! The photocell is very responsive to infra red! On the other end of the scale, I had to move the UV flashlight to within 2-3 inches of the photocell to get any readings.

It is important to remember that I'm measuring the current output of the photocell which has no color compensation. But other than that, works fine.

ADDED:

I've been told that as the batteries start to die, the light from an incadesent(sp) bulb starts to shift into the infra red. That being the case, I would think that a comparison between LED and bulb would be ok at the start of a run when the batteries are fresh.

 

[brightnorm]

Originally posted by Rebus:
....And to change the subject. I wish the statement:
"10 times more battery life than an incan" would
go away fast. We all know that to get anywhere near
as much light as a 2 cell incan light, you need about
7 leds and 3 cells and from this you might get 2 1/2
times the burn time. This plus the fact that it is
a totally diff. kind of light really needs to be
passed on to people just getting into leds....I don't think that manufacturers do themselves a
favor with wild claims of efficiency & runtimes.

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

Your points are important and too often glossed over. Many of us somehow assume that LEDS are much more efficient than incandescents. Unfortunately they're not. Until research focuses primarily on LED efficiency we'll still be running around in circles, squeezing out an extra lumen here or there in a futile quest for major increases in brightness and runtime.

Of course this also applies to incandescents. In a recent post Kogatana mentioned Mag's development of a Magcharger lamp that is brighter and consumes less power than its predecessor.

That's the direction in which we must move.

Brightnorm

 

[Rebus]

Charles Bradshaw posted:
------------------------------------------------
The current measurement, as Roy stated several times before, is from the photo receptor, not the light's batteries! His plots are about how long the thing puts out light for a given type of battery.
----------------------------------------------
Charles, the mA that I quoted came from the photo
receptor readings, not the battery outputs.

I understand Roy's method of testing and was
just making a point about our aparent
inability to make meaningful comparisons between
incan and led light.

-Rebus

 

[Roy]

Oooops! Double posted

 

[Rebus]

Roy, According to your plot on the oem bulb mini mag
it puts out 34.2 mA DC max and the Techass puts out
.446. That is about 76 times more mA than the techass.

30 min. before the mini mag goes dark it is still
putting out 5 mA which is still 11 times more than
the .446 of the Techass. I don't think so.

What is this telling us?:

1. The metering system that you are using has a
large bias for the photons that come from an incan light.
Is a photon, is a photon, is a photon, or what?

2. The beam characteristics of the mag consentrate
more of it's light on the collector.

Can the whole thing be explained by number 2 or does
does no. 1 play a larger part than we think. Is led
light a totally diff. animal from incan light?

I sure don't think that the mag is 76 times brighter.
I have seen led lights that I thought were about as
bright as a mini mag, but as you can see from Roy's
plots it's unusual for an led to put as much as even 1 mA.
I would like to see a plot of the Dorcy Cool Blue that
is able to focus it's light.

It seems to me that led light might be more efficiently
used by the human eye than incan light, making it much
more useful in the flood situation. It amazes me how
my Infinity can completely light up a 12x12 room.

And to change the subject. I wish the statement:
"10 times more battery life than an incan" would
go away fast. We all know that to get anywhere near
as much light as a 2 cell incan light, you need about
7 leds and 3 cells and from this you might get 2 1/2
times the burn time. This plus the fact that it is
a totally diff. kind of light really needs to be
passed on to people just getting into leds.

I don't think that manufacturers do themselves a
favor with wild claims of efficiency & runtimes.

In a way,I quess that we don't expect to be told
the truth when we read a product description, and
that is SAD!! Maybe at this point we just have not
figured out how to describe this new technology?

Hope I haven't rambled on about things already said
and accepted...

-Rebus

 

[Charles Bradshaw]

Okay, Rebus, understood.

 

[Roy]

For those interested, I mounted a MagmaLED in a AAA Minimag and ran a Runtime Plot on it! The results can be found by searching this forum for "Run-Time Plot - MagmaLED-AAA".

 

[Gene]

I had an old AA Mini Mag laying around and went for one of the MagamaLED's due to it's price of $15.00. No, it's not as bright as an Opalec NewBeam or even the stock Mini Mag bulb but to me it's nice flood of LED diffused light, is VERY handy. I know most folks are into "BRIGHT" but with this conversion, it's just right for trips around the house without waking anyone up and extremely handy for camping. Like I and others have said, it's amazing how bright "dimmer" lights are when your eyes become accustomed to the darkness. It's the cheapest LED Mini Mag conversion out there and to me, it's worth it. Now with Roy modifying it so it can be used in a AAA Mini Mag, I just happen to have an old AAA Mini Mag lying around. Thanks Roy!

 

[Empath]

Originally posted by Atrick-Pay:
Is this as bright as a Arc-AAA? or a Photon2?

<font size="2" face="Verdana, Arial">Brighter! At least there is the appearance of more brightness. Due to focusing, you get a light more like a Pal, Impact or Dorcy Cool Blue.

 

[Wulong]

...finally got this post in the right thread.

Do any of you have beam-shots of the MagmaLED on AA's?

 

[Roy]

Here is my first attempt at beam shots! The target is about 10 inches away and the tic marks on the target are at one inch.

WriteRight applied to the lens will smooth out the rings in the beam pattern.

 

[Wulong]

Thanks for the pics, Roy.

The hotspot in the left-hand shot looks so much brighter. Are these the same lights, with WriteRight being the only difference?

 

[Roy]

The pic on the left is with the light in tight focus and the one on the right is in wide focus. See the "Run-Time Plot - Magmaled AAA" for an example of what WriteRight will do.