Alright guys, sorry for the long wait time. I'm back and ready to work on my harp again. As it turns out, Calc 2 in college takes up a lot more time than you would think.

Anyways, I've been looking at the lasers themselves and they seem to have a resistor in front of the line that leads to the laser, meaning that it needs less power. But they *all* have the resistor (all 8 of my lasers). So here are my questions: How to I tell what kind of resistors they are? I have a multimeter - can I use that? Also: how do I calculate the energy the lasers will need? Is it something like...

Voltage needed by the individual lasers (so, if they each need 4.5 volts, I need one 4.5 volt wire)

with

the amps each laser needs * the number of lasers (8 lasers, 15 mA each, so 120 mA)

and

one resistor equal to the voltage of the resistor already in the lasers BUT equipped to handle 120mA

Is this correct, or am I missing something? Thanks for your patience and help all!