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Author Topic: DIY LED wiring question  (Read 122 times)

Offline Guns Akimbo

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DIY LED wiring question
« on: July 11, 2017, 10:57:06 pm »
I'm halfway through the second attempt of my little Bandai ISD kit and am using a trio of 1.8mm cool blue LED's for the engines this time. I got a bag of ten lights along with ten 470 Ohm resistors. Now, I'm now ashamed to admit that my electrics skills are slightly lesser than my building skills, lol, and I'd like to ask how to wire these things up. Parallel with a single resistor on the hot leg between the last LED and the power source (using a AAA battery box)? Thanks for any help!

Offline The Man/Kind Project

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Re: DIY LED wiring question
« Reply #1 on: July 28, 2017, 03:32:19 am »
I'm a novice, so knowing that -- I put a resistor on each cathode leg of the LED.

Offline madmonk

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Re: DIY LED wiring question
« Reply #2 on: July 28, 2017, 04:47:32 am »
It doesn't really matter which leg you wire the resistor in. I usually put it in the -ve (short) leg of a LED.

Wiring the 3 LEDs in parallel then adding a single resistor is not a problem, what voltage are you using with the AAA batteries as the 470 Ohm resistor may be too big and dim the LEDs too much, worth testing first if you can.

Offline scottminium

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Re: DIY LED wiring question
« Reply #3 on: August 03, 2017, 07:46:58 pm »
I'd recommend a wall power supply just to keep the input voltage constant.  After just a little while batteries end up giving you fits as the voltage dips slightly and the lighting is not consistent.

As for the amps and voltage, wiring one resistor per LED will reduce the heat dissipation required of the resistors.  Not to geek out, but wattage (heat) = current(squared) * resistance.  Three LEDs in parallel, drawing the same current will be 9 times the wattage.  This might not be a problem, but if you want to ensure long life, reduce the current and the wattage.

For 9V, you can wire 1 LED through 2 470ohm resistors and still get quite bright light, with minimal wattage and current.  (resistors in series!)

The positive ends and negative ends would then be soldered together to minimize the number of leads coming out of the kit.

I could gen up a simple schematic if that helps.
"If there's a bright center to the universe, you're on the planet that it's farthest from."

 




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