IR package for Motion tracking

[Jamie]

Greetings!

this post is a bit long - tying to explain a bunch...

I am trying to construct VERY small IR LED packages for use on dancers for a real-time motion tracking/motion capture system.

I am by no means an expert in this world at all.

In doing a bunch of research on-line about LED's and what not I ran across "Throwies"
(LED taped to a CR2032 battery with a rare-earth magnet)
based on this idea I have been working with up to 5 HSDL-4220 (30° beam)

The continuous electrical specifications for them are 875nm center, max 100mA, 1.5V. At a 100mA the 4220 delivers 76mW/sr and 4230 delivers 150mW/sr (in the middle that is).
​

These work fine but the problem is that at a distance of 60 feet or so they end up being the size of about a pixel or two in the camera view and therefore difficult to track.​

SO
I am trying to figure out how to make something else bigger and brighter -

limitations include:
No heat sink
​

(??? - unless I can figure out how to make it small and aesthetic and ok next to the dancer's skin)

Small Battery - button size - could move up to a CR2450 (3 volt, 610mAh)(or 2?)
​

the LED's I have found include a EDIXEON IR I
"can be driven at 700 mA or 1000mA and reach 280mW and 400mW"
http://ideacomponents.blogspot.com/2007/03/high-power-infrared-emitters-gain-in.html​

OR​

[FONT=Arial, Helvetica, sans-serif]from ebay a 200mW 10mm High Power InfraRed (IR) LED w/Triple(3) chips[/FONT]
[FONT=Arial, Helvetica, sans-serif]Voltage: 1.5V~1.6V
[/FONT][FONT=Arial, Helvetica, sans-serif]Angle: 15~30 degree
[/FONT][FONT=Arial, Helvetica, sans-serif]Current: 140mA, Peak(pulse): 700mA
Power: 200mW[/FONT][FONT=Arial, Helvetica, sans-serif][/FONT]or from the same ebay distributor:
a 3 or 5 watt LUMILEDS 'star'
[FONT=Verdana, Arial, Helvetica, sans-serif]Vf: 1.5V~1.6V
If: 750 mA
Dimension
Backplate(W): 19.9mm[/FONT]

any thoughts would be appreciated!
thanks
jamie
​

 

[Bushman5]

try the tiny clip on IR Mini Flasher lights from pelican: they are an 1.3" long, IR, visible from the sides and front (ising IR camera or NVG)


http://pelican.com/lights_detail.php?recordID=2130IR

 

[Jamie]

that seems like a great option - do you think it's possible to stop the flashing?

thanks again!

jamie

 

[Jamie]

I wonder if anyone has any suggestions about building something -

the blinking in the pelican beacon won't work as I need a constant light source in order to track it well @ 30 frames/second....

thanks
jamie

 

[datiLED]

Check out these IR LED's. The dealer claims that they can be powered @ 1.5V. At the lower voltage, you may not need any additional heatsinking.

 

[Jamie]

thanks! those look great -

I have been reading around on the site and form my understanding it is better not to direct drive these - right?

so I need a resistor?

can I use a CR2450 3V 610 mAh button cell to power this?
trying to avoid even a AAA battery...


the quote from the link you sent me is:
"They draw 1.5V only, so you may use our newest AA step-up voltage circuit (with voltage adjustment) with it. You may want to turn the voltage output all the way down (2.0V), and add <1ohm of resistor to reduce the voltage to 1.5V-1.6V"

Testing:
1W version: 1.5V @ 350 (1W)
3W version: 1.3V @ 350mA (1W) 1.5V @ 700mA (3W) 1.7V @ 1A (5W overdriven)


again, many thanks -
I'm shooting in the dark here (and could use so IR to help out!)

best
jamie