I have a quick question that I can't seem to find the answer on.

After trying out the Radioshack LED's I've decided that they are probably too weak for this activity, most of the light is on the top of the LED and it's not extremely bright to begin with, so now I'm going to make a new pen with the 782-tsal6200 LEDs.

Now I noticed they have a higher voltage, so I'll probably need a resistor and a new battery (I was using 1.5 N sized) so I want to know what my options are, and what are the risks of not using a resistor?

Alright, I only need it for one presentation but I'll be testing it a lot so I'm not going to risk it.

How would I know if the resistor is working (basically since I'm fairly bad at soldering, how do I know if I made a good contact).

Kurtangletn
Check my post: http://www.wiimoteproject.com/ir-pens/electronics-101-sharing-my-mistakes-or-learning-electronics-the-hardway-t834.0.html

Has links to calculate the required resistance and the really smart dude at your electronics shop are good source of info too.

Use your mobile camera to check IR-LED is working (they are IR sensitive), the photos on the post are of IR-LED through my Dopod (HTC) 838Pro.

Also has links to the Vishay Data sheets for the three commonly used IR-LED. The 6200 has a slightly lower viewing angle than the 6400. Would love to know how well it works.

benpaddlejones