# Would this be the correct diagram for wiring LEDs with different voltages?

Since I haven't dealt with voltages/current/etc since highschool, I'm not super confident in my abilities to not blow up a bunch of LEDs - I read a few guides, but would appreciate if someone could confirm I'm on the right track!

I'm using two 9v batteries adding up to 18v to power the system, and running 10 LEDs in 5 groups (2 2.2v, and 3 3.2v). The total voltage adds up to 14v, so my logic follows that if I use Ohm's Law on the two groups running 2.2v at 20mA, I need a 100 Ohm resistor on both to eat up the remaining 4v (2/0.02 = 100).

Would I be correct in my logic, or is there something I'm missing? Any guidance would be very appreciated!

• You put 18 VDC on two LED and a 100 Ohm Resistor.... That don't looks good
– Mike
May 27, 2021 at 10:07
• And you put 18VDC on two LED without a resistor.....really bad
– Mike
May 27, 2021 at 10:08
• "That don't looks good" and "really bad" doesn't help me get any closer to an answer... May 27, 2021 at 10:20
• i didn't know the exact current that your LEDs needed because you did't gave us the parameter but, check this link and i think it works for you : drive.google.com/file/d/1A4EdAMraDbu5bhKNqz6VVpqliOIbs32v/… May 27, 2021 at 10:59
• Ahhh! That makes far more sense - I think I got a grasp on it now, thank you so much! I really appreciate the effort you went through to illustrate it for me :) May 27, 2021 at 11:11