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Resistors on each led? Answered

 I am designing a led array consisting of 17 leds in parallel using 4.5 volt power supply.The led calculator is telling me to use 62 ohm resistor on each - leg of the LEDscould I just use one 62 ohm resistor right after the power supply? Or maybe like 1 or 2 100 ohm resistors?

I'm using blue leds
3.3 max voltage
20 Ma



Best Answer 8 years ago

There should be no problem using one resistor.  Just use a resistor big enough to handle the load or it will overheat and burn out, but your leds should be fine.

I don't know why almost all of the diagrams show a resistor for each led except if you're mixing colors of shapes and they take different voltages you can account for that by using a diff. value resistor for each type led.

And should I happen to be wrong on this (but I'm pretty sure I'm not) someone will correct me.  Sometimes it's easier to get a correction than an answer.

You'll have to recalculate the value of the resistor.

Tell me what you get as the value and I'll tell you if I got the same value.

Thanks, I decided to just use 100 ohm resistors in front of each led , they didn't need to be too bright for this project. I'm happy with the result.


All that matters in the end is that it works and you're happy with the result.

Try a bread board and use a 225 ohm resistor. That should work. If it doesn't, use that 62 ohm resistor on it but only at our own risk. You might blow your LEDs.