My project

kahless78 · Post by **kahless78** » Thu Apr 01, 2010 4:56 am

Ok after talking with Atlantis in a previous post I am ready to start my lighting project. I plan on using two four AA battery packs. Each pack will be 6.0 volts. I have a really good idea about led's now so here is my plan.

Using the two packs i will split the ship in to two sections, one for the saucer section the other for the secondary hull. I will be doing individual runs off the power supply with two main hubs located in each section, one positive and one negetive. in turn the hubs will be wired to two switches then to the battery packs.

I will wire each led to these hubs using the correct led resistor calculated for my power supply. My white leds which I donot have an exact number count yet will need a 150 ohm resistor for each , the formula I got for that is 6.0 minus 3.2 divided by 20ma = 150

I will be using three red led's and I will need a 150 ohm resistor for each. The formula i got for that is 6.0 minus 2.6 divided by 28ma = 150 ohm

I will be using two green led's and I will need a 150 ohm resistor for each.
The formula I got for that is 6.0 minus 2.4 divided by 10 ma = 150 ohm. This set will run in a series: example - power supply led to led to 150 ohm resistor to ground. Not power supply + led + resistor + ground like the rest.
This is the only one I will do.

Now I will be using blinking led's for my nav and strobes. Just the led nothing else. I know that it ill not be screen accurate but this build is getting expensive and I need to save money lol. I need a total of eight blinking led's and I will need a 68 ohm resistor for each of those. The formula I got for this is 6.0 minus 3.8 divided by 35ma = 68 ohm .

Well tell me what ya think!

mhvink · Post by **mhvink** » Thu Apr 01, 2010 12:19 pm

Kahless,

Sounds good. The only flaw I can see is with your green LEDs (in series).
When running LED's in series, you need to subtract the voltage for each LED. I think it should be 6V -2.4V twice or 4.8V total voltage loss. That would give you 1.2 volts across the resistor at 10mA giving you a resistance of 120 ohms ( your original calculation of 6V -2.4V should have given you a voltage of 3.6V across the resistor, at 10mA (or 0.010A) giving a resistance of 360 ohms, not 150).

Other than that, you are spot on.

Mike

kahless78 · Post by **kahless78** » Thu Apr 01, 2010 2:46 pm

mhvink wrote:Kahless,

Sounds good. The only flaw I can see is with your green LEDs (in series).
When running LED's in series, you need to subtract the voltage for each LED. I think it should be 6V -2.4V twice or 4.8V total voltage loss. That would give you 1.2 volts across the resistor at 10mA giving you a resistance of 120 ohms ( your original calculation of 6V -2.4V should have given you a voltage of 3.6V across the resistor, at 10mA (or 0.010A) giving a resistance of 360 ohms, not 150).

Other than that, you are spot on.

Mike

Yep you are right. Since I am doing just those two in a series I forgot to add the 2.4 twice. Thanks for catching this for me!!!!!!!!!

kahless78 · Post by **kahless78** » Thu Apr 01, 2010 3:52 pm

Now I just need to figure oout what i will use for the hubs lol?

mhvink · Post by **mhvink** » Fri Apr 02, 2010 1:12 am

Okay, for the hub . . .

#1 - Get yourself a soldering iron and a small roll of solder.

If you have a piece of solid copper wire (like "Romex" house wire), strip the insulation off of two pieces about 1/2" long. wrap the ends of your lighting wires around each piece of copper wire and solder the wires to this "buss" bar, making your hub.

Something like this: __|__|__|__

__<--(Copper buss wire)

| <--(lighting wires)

Remember, don't let the two hubs make contact with each other or your lights won't work.

Hope this helps.

Mike

kahless78 · Post by **kahless78** » Fri Apr 02, 2010 1:40 am

Thats is exactly what I was thinking too lol