LED testing

[mguerramd]

Remember that if you use LEDs to test your firing systems the LEDs are polarity sensitive. If you hook them up one way and they don't fire when you hit your cue, reverse them to see if they then fire. You don't want to hook them up in reverse polarity and then think all your cues are bad! I also mentioned in another thread that my cue won't show continuity with the LED I had plugged in to it, but another LED would. I believe that is wrong. Don't use LEDs to test continuity. Use a known good match, Talon, or shorted test leads.

 

[DexTee]

Also, you may need higher voltage supporting LEDs or ones with built-in resistors … the ones I used to test my initial cheapo firing system blew right out, but these performed fine:

 

[SpreadFire1A]

Usually, LED's have one "leg" that is longer than the other one, and that's the positive. As for burning out the LED's, the following web page let's you plug in the voltage and other info, such as the color of the LED (it does make a difference), so you can choose the right resistor.
LED Resistor Calculator - Inch Calculator And as a secondary choice: LED Resistor Calculator