led lighting experts

[cruisermedic]

im looking to light the inside of a case with some l.e.d's. its more of a novelty thing than to actually be worth lighting it. i want to do it just cause i can

i dont know how many ill use im guessing probably right around 20. ill need a push button style switch so the lights come on when the lid is opened and i will need it to be ran off batteries. a few 9volt or a few AA batteries wired together like in a cheap l.e.d. flashlight. hell i might even take the battery pack out of one of my junk flash lights i got now.

im ok on the actual wiring of it but isnt there a few math equations ill need to know for the number of lights and what resisters to use?

thanks,
steve

 

[george_tlc]

LED Resistor Calculator if you're just using cheapo 5mm style LEDs.

If you want 20 LEDs then just wire each LED with its own resistor and then wire each LED/Resistor pair in parallel with the next. With white LEDs you'll need at least 3 AA alkalines etc to provide sufficient voltage.

cheers,
george.