I'm working on lighting up an entire LEGO city from my nephew. But the problem is I need a lot of leds with different amperes and voltages ( I'm gonna put them in parallel). So my 2 questions are :
Do I need to put a resistor before every led? or can I just put a resistor in front of a bunch of leds ( I have around 15-25 leds per resistor)?
I need for most of my leds about the same value of the resistor (around 150 Ohms). Can I put the resistor of exact 150 Ohms (1% tolerance) in front of the leds? or do I need to set the value a little bit higher with an extra resistor?
EDIT: also in the comments: 41 yellow and red leds have 2 volts and 20mA About 30 white leds have 3.5 volts and 20mA and about 10-20 leds have 2.6 volts and 70mA