FreeTrack Forum

First of all: THANK YOU to all who have developed this fantastic piece of software...THANK YOU for making it freely available...and THANK YOU for having so much patience with fans who know next to nothing about electronics!

I am quite ignorant when it comes to things such as resistors and Ohms.  My planned 3-point hat will utilize...

Power supply: 9 volt battery

3 - SFH 485 IR LED's with
1.5v forward voltage
100mA

The LED Setup Wizard tells me 47 Ohms +/- 5% with output of .43 Watts.

So, when I go to Radio Shack what do I ask for?  Do I get a 50 Ohm, 1/2 Watt resistor?  I'm very confused!

Forgive my ignorance, and thank you again, and in advance!

Hello Geewiz


1)
First of all, don't drive your SFH485's at 100mA. This can only be reached in specific use, and it's not the case here

use :

Good values are usually :

from 25 to 50mA , if your webcam is IR modded (25mA will do most times)

from 50 to 75mA, if you use a stock webcam (not IR modded).

2)
The wizard suggests you a standard resistor value, so if it suggests 47ohms, you'll find 47ohms   ... No need to go for a 50ohms (which is anyways harder to find.....   )

3)
The wizard gives you the power dissipated in the resistor. As a rule of thumb , use a resistor at least twice as big as the dissipated power.

So, for a 0.43w dissipated power , i'd suggest to use a 1w resistor.

The next release of the wizard will incorporate resistor power suggestions.


So i'm afraid you'll have to recalculate the whole thing , based on your webcam model (IR or non IR).
Or just tell us the model, and we'll help



Cya.

Tristan...thanks!  You are the best, and so is your tracking software!  I'm making this for my father-in-law to use on his FSX/B-17 flight simulator.  He's   an 88 year old veteran B-17 pilot, and will be thrilled to have this!

Thanks again!

   WOW    

88 years, former B17 pilot and still playing FSX ??

Thumbs up  

I just hope i'm still in such a mood if I reach this old  

Tell us if he appreciated freetrack !!!