12/2/05
Plans:

1/8/06
I have the cube done as well as the base and part of the hood.  The LED's arrived this week and I will be putting them together into a light source when I have the time. 

5/29/06
I finally got around to posting the schematic and board layout for the LED controller.  This week I hope to assemble the light board and test it out. 

6/1/06
Over the weekend I breadboarded an LED for the light panel.  The math should be simple:

V = IR

that is, Voltage = Current * Resistance, so V should be about 3.9 (5.1V supply - ~1.2V drop across LED = 3.9), Max current on LED is 20ma (.02A), so the resulting equation is:

3.9 = .02R

195 = R

That at least got me in the ball park for the current limiting resistor that I will end up using.  I swapped out a few and tested the current using my BK Precision 388B Multimeter (which I highly recommend).  Using a 100 ohm resistor, I was able to push about 18.5 ma to the LED, which is right about where I want to be.  I wanted to run somewhere between 90-95% of the maximum current as to not burn them out too quickly, after all, some of them will be running 12 hours at a time. 

Mike (11/21/2007 9:11:09 AM)
Could this circuit be modified to control main lights.....12 hours on 12 hours off? It should be able to fire relays, yes?

Reply: Yes, it would work as is for driving relays. You could use a 5-24v power supply without changing anything in the circuit, since 5vdc/120vac relays are a little difficult to find but not impossible.

Kevin (8/2/2007 1:37:01 PM)
Any finished product pictures? What did you use for a sump\fuge? You should really make and sell these as a hobby, Nano is a REALLY big thing these days.

Reply: No, mainly because I haven't finished it yet. I started on that project quite a while ago and for one reason or another it got put on the back burner. It still sits in my basement in pretty much the same form as the last pictures. I will probably pick it back up this winter when I have some time. I didn't plan to use a sump on this particular model as I wanted it to be coral only and very portable. I had thoughts when building it to plumb bulkheads in it for using a sump, but it was too late at that point. Unfortunately, the time, effort, and money that goes into a tank this size is still quite sizable when compared to what people would be willing to pay for it.

TIM (5/17/2007 4:01:24 PM)
HI THATS A NICE LITTLE SETUP. I WANT TO SET UP ONE AS WELL. WHERE DID YOU GET THE TANK MADE AT?

Reply: Thank you. I made the tank myself out of 1/4", cell-cast acrylic. I make all of my tanks myself.

Fabian (3/14/2007 12:25:07 AM)
How you use this led timer? with a computer?

Reply: No, the timer uses a Basic Stamp microprocessor as a timer. It is initially programmed by a computer, but runs on it's own.

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