FreeTrack Forum

Hi folks!

I live in a fairly small town without easy access to electronics shops.  I was hoping to assemble my kit this weekend, but have run into a bind.

Here are my specs:

3xIR LEDs (Nexxtech brand from The Source, cannot find beam info)
Reverse voltage:  5V
Continuous forward current: 150mA
Forward voltage:  1.3V typ, 1.7V max
Radiant power output: 13-15mW
Wavelength at peak emission:  950 nm
LED Measurement:  8.7mm tall x 5mm wide
(NO idea what most of that means.    )

Power supply
DC adapter 6V 300mA
The calculator does not allow me to input the 300mA from the PS.  Is this valuable information?
I also have another 300mA PS with variable voltage outputs from 1.5-12V

Ultimately, my problem lies with the resistor.  I have 1/4-watt, 5% resistors in a package.  The come in 100k, 220k, 330k, 470k, 1m ohm

I also have 100, 220, 330 & 470 ohm in another kit.

Is there any way I can make this work without a few hours drive to a supply store?

Many, many thanks.  This is a great resource!

Cheers,
Craig

Addendum question:  What if I just used a 100Ohm resistor?  Would that cause a battery overheat or something?

Cheers,
Craig

Go into the calculator... you only need the values it asks, so 3 led's, 150 mA, I believe it would be an unregulated adapter and then put in 6 V

SETUP MODEL     3 LEDS clip on headset or 3 LEDS cap
(6 DOF - all rotations and translations)
POWER SUPPLY    Power supply (V)    6 V
!! Attention :
Type d'alimentation précisée : non régulée
These unregulated power supplies usually provide a higher voltage than indicated (about 30%).
Power supply voltage adjusted for processing : +30% => 7.8 V
LED    Led forward voltage (V - manufacturer info)    1.7 V
Led forward current (mA - manufacturer info)    150 mA
LED ASSEMBLY     S : serial assembly
RESISTOR COUNT    1 resistor(s) needed for the complete kit
RESISTOR THEORICAL VALUE    18 Ohms
RESISTOR CHOICE E24 SERIES    Resistor value    18 Ohms 5%

Current    150 mA
Dissipated power    0.41 Watts
Total current in assembly    150 mA

Therefore hook the led's up in series with the 18 ohm resistor in between the negative terminal of your battery and the negative terminal of your first led