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



Laser Pointer Store

DFW Spring Fling, Saturday, May 14, 2011

jib77

New member
Joined
Jun 19, 2010
Messages
718
Likes
69
Points
0
Pizza w/ headcount is best ... that way there is no guessing at how much food to buy.
 

jib77

New member
Joined
Jun 19, 2010
Messages
718
Likes
69
Points
0
: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.
 
Joined
Oct 4, 2010
Messages
33
Likes
2
Points
0
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.



















Does anyone know who's these are? I have one of your items, PM me
 

LarryDFW

New member
Joined
Dec 6, 2008
Messages
1,577
Likes
108
Points
0
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:


Thanks for your work putting this event together.

LarryDFW

P.S. Your grey #18650 cells tested @ 122 milliohms
 
Last edited:

strik3

New member
Joined
Apr 18, 2011
Messages
145
Likes
3
Points
0
wow some amazing looking builds there. wish i could of come. but its a bit far to travel from aus
 
Joined
Oct 4, 2010
Messages
33
Likes
2
Points
0
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!
 

LarryDFW

New member
Joined
Dec 6, 2008
Messages
1,577
Likes
108
Points
0
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:

LarryDFW

New member
Joined
Dec 6, 2008
Messages
1,577
Likes
108
Points
0
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 . . .



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:

LarryDFW

New member
Joined
Dec 6, 2008
Messages
1,577
Likes
108
Points
0
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:
Joined
May 4, 2009
Messages
5,462
Likes
551
Points
0
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
 




Top