Welcome to Laser Pointer Forums - discuss green laser pointers, blue laser pointers, and all types of lasers

Buy Site Supporter Role (remove some ads) | LPF Donations

Links below open in new window

ArcticMyst Security by Avery | Browser Hide by Avery

DFW Spring Fling, Saturday, May 14, 2011

Pizza w/ headcount is best ... that way there is no guessing at how much food to buy.
 





:bumpit::bumpit::bumpit::bumpit:

Two days away ... hope everyone can make it! Bring your lasers, flashlights, LPMs, GITD stuff, etc. Ill be bringing a few of my drivers for trade/sale.
 
Thanks again for all that made it!! Too bad we had to change the location at the last minute, but it all worked out in the end.

Thanks for all the help and patience, and especially for the good food!

Here are a few pictures, if you have more please post them here, or get them to me so I can.

100_0250.jpg


100_0248.jpg


100_0247.jpg


100_0246.jpg


100_0245.jpg


100_0244.jpg


100_0243.jpg


100_0242.jpg


100_0241.jpg


Does anyone know who's these are? I have one of your items, PM me
100_0240.jpg
 
Hi Matt;

With the very nice weather, everybody was out at the parks.

I wish we had a photo of the 15 lasers pointed at the sky at the same time.

My lasers and lights were on the turquoise cloth.

Here is a photo of "jib77" and his array:
springjib77.jpg


Thanks for your work putting this event together.

LarryDFW

P.S. Your grey #18650 cells tested @ 122 milliohms
 
Last edited:
wow some amazing looking builds there. wish i could of come. but its a bit far to travel from aus
 
P.S. Your grey #18650 cells tested @ 122 milliohms

Put that in laymen terms, sounds low to me, but how does that compare to regular Sanyo 2600 mAh cells? Is that lower resistance, or is there a downside of having such large capacity cells?

I had a great time anyway, maybe I should rent a small pavilion in one of their other parks for next time!
 
Matt;

Some new high power lasers & lights are demanding quite a bit of power from these #18650 cells.

Most 18650 batteries struggle to deliver enough current to drive the hosts @ ~3-4 amps.

This is where internal resistance is a critical parameter to output full power.

I previously tested a sample of some new Sanyo 2600mah #18650 cells @ 70° F:

V1=4.20 VDC No Load
V2=4.10 VDC Loaded
R = 3.1 ohms
Internal resistance : 76 mOhms @ 1.32 amps load (I test @ 1/2 C load rating)

According to the respected Battery Testing Experts @ Cadex :

75-150 mOhm - Excellent (your Panasonic 2900mah cells)
150-250 mOhm - Good
250-350 mOhm - Marginal
350-Up mOhm - Bad

mOhm stands for milliohm or 1/1000 of an ohm.

Your cells were rated excellent . . .
& they would have been even better, if they were newer.

LarryDFW
 
Last edited:
Here is the brightest light we tested, from one of the home-lighting enthusiasts.

10,000 Lumens powered by eight high-current A123 power-tool cells . . .

spring10K.jpg


We were . . .

cooking mouth-watering Bar B Q , :beer:

testing laser powers on two thermopiles,

testing flashlight power in an integrated sphere,

disassembling & showing building techniques.

The six hours went by too quickly.

LarryDFW
 
Last edited:
Flaminpyro;

It was, of course, an multi-LED array (I'm guessing ~100).

The voltage was 30 VDC @ 3.1 amps for 93 watts.

That is ~108 lumens per watt.

Definitely lit up the woods !!

The owner had converted every light in his house (over 100),

to LED's.

Most were warm-white (3000° K).

LarryDFW
 
Last edited:
I'm in the process of converting all my lights in the house to Led also, it slows down the power meter :na:
Thanks Larry for sharing...



Flaminpyro;

It was, of course, an multi-LED array (I'm guessing ~100).

The voltage was 30 VDC @ 3.1 amps for 93 watts.

That is ~108 lumens per watt.

Definitely lit up the woods !!

The owner had converted every light in his house (over 100),

to LED's.

Most were warm-white (3000° K).

LarryDFW
 





Back
Top