Moonlight questions

[75gMKT]

I have just purchased a bunch of blue leds to make a moonlight set up with and my only question is what do/should I use as power source?

 

[Wizzard~Of~Ozz]

What value are the resistors, if you don't know then you can post the colour bands and I'll tell you what the values are..

I think I made a detailed post in one of the other moonlights threads here.

Ahh, here it is
http://www.aquariumadvice.com/viewtopic.php?t=53270&postdays=0&postorder=asc&start=25

 

[krap101]

lol i remember that thread

 

[greenmaji]

Shweet work there ozz
And JProx didnt even have to answer LED questions this time LOL

 

[75gMKT]

All I am wondering is what i need to get use to power the lights, like an inverter or something of that sort, the LEDs that i bought already have the resistors installed, so all i can tell you right now is that they are of the 10mm size, unless i cut one open i cannot tell you the resistor color/size, so any general advice is welcome. Thanks

 

[Wizzard~Of~Ozz]

Did the package come with a note about recommended voltage? if it was a sealed unit then it should have.

 

[75gMKT]

they are of the home made variety, and the heat-shrink tubing is already on them, the info said that they can take any where for 6-14 volts, i don't know how that correlates to plugging them in to a wall socket type fixture, will any one work?

 

[greenmaji]

With the correct number of LEDs and the correct size resitors you can calculate out what size inverter needed.. the calculations are in the other LED threads.
HTH

 

[Wizzard~Of~Ozz]

You will need a transformer. If you can get a universal transformer (one with a voltage selection switch) then you can start at 3v and keep moving up until you feel the resistor get warm (don't worry, you're gonna feel it through the heatshrink) or the LED pops. then you know it's too much.

The resistors I would have to guess are designed for 14v so a 12v transformer would *Probably* be correct, tho 9v would be safer, you would just need more LEDs

Also keep in mind LEDs are polarity sensitive, so if you hook one up and get no light, try reversing the power wires.

DO NOT hook an LED up to AC Voltage, and never directly to a 120v outlet. you will exceed the forward and reverse limits and at best burn your hand, at worst you will send plastic shrapnel flying everywhere.

 

[TwoHobbies]

Any 9-12 volt DC adapter 200ma or higher will work, RadioShack about $15, or I have a few laying around if you would like one.

 

[75gMKT]

ok so i cut one open and the resistor colors going away from the led are green, blue, black, black, red, and the resistor as a whole is a light blue color and i plan to put 8-10 or how ever many you recommend over a 75 gal tank

 

[Wizzard~Of~Ozz]

That value can't be right.. It would be 5600Ohms plus (never heard of a red tolerance band, Brown maybe?)

Do you have a multi meter you can measure the resistance with? Might prove a bit more reliable.

Twohobbies, Not to be crude, but that is an unqualified answer that has the potential to harm someone.. If the resistor was rated for 3v then putting 12v to it will result in plastic flying or resistors heating up to dangerous temperatures.

 

[75gMKT]

on seccond glance it does looks to be green, blue, purple, black, brown, or orange ,stupid light. Does that help at all?

 

[greenmaji]

you can get a muli-meter for really cheap, less then 10 bucks for an cheap electrionic around here and about 5-6 bucks for an analog.
wallyword, ACE, look around if intrested..

 

[TwoHobbies]

I did read the info that came with them said 6-14 volts, 12 volts would work fine as long as its DC.

Most, but not all----packages like that are designed for auto use ( 12 volts)

I also don't understand why resistor values are important when we don't know the led voltages. JMO

 

[Wizzard~Of~Ozz]

LED voltage drop is typically .7v, but that can be guessed to be 1v if you like. the important number is the current required by the LED. that is the number that qualifies the resistor value. with the incorrect value there may be too much current flowing through the LED and cause it to fail prematurely or worse, blow up.

 

[75gMKT]

so shold i get a 12 volt or a 9 volt adapter they have ranges from 500-1500ma ?

 

[Guest]

i just use an old computer power supply and it works fine. it will run 6v or 12v dc.

 

[75gMKT]

well i was looking at gettiung one of those adapters for radio shack so i was wondering what one i should get exactly.

 

[TwoHobbies]

Any 9 or 12 volt DC 300-500 ma adapter should work. The higher the ma number the more leds you can run.

The higher the ma number the more expensive the adapter the more leds it will power. I run 10 blue led's in my nightlight on 300ma with no problem.

Part number 273-1773 From the web sight ....$17.99.... ouch