TheFishMan65
New member
Are they connected directly to the power supply?
BSOD LED build
- Thread starter BluScrnOdeth
- Start date
BluScrnOdeth
Darin Schmidt
the psu has a POT, then to a quick burn fuse then to the leds
TheFishMan65
New member
You are going to need a higher poer pot. YOu will only be dropping a few volts at most so you need 0-maybe 5 ohms. The cuurects (assuming one string) ill be 1 amp (or whatever) so the voltage will be 0 to 5 volts and the poer will be 0--5 watts.
Don't know here you find this type sorry.
Don't know here you find this type sorry.
BluScrnOdeth
Darin Schmidt
alright, thanks fishman, i'll take a look around tomorrow and see what i can find.
BluScrnOdeth
Darin Schmidt
TheFishMan65
New member
How many strings are you running through one POT? How much voltage do you think you want to drop?
watts = voltage * current
voltage = current * resistacne
so
watts = current ^2 * resistance
5 watts / 5 ohms = 1 amp (square root of 1 = 1) will get hot at 1 amo
5 watts / 50 = .1 amps^2 (sorry don't knw this one off the top of my head - but not much current)
You probably 10-20 watts and 5 ohms.
watts = voltage * current
voltage = current * resistacne
so
watts = current ^2 * resistance
5 watts / 5 ohms = 1 amp (square root of 1 = 1) will get hot at 1 amo
5 watts / 50 = .1 amps^2 (sorry don't knw this one off the top of my head - but not much current)
You probably 10-20 watts and 5 ohms.
BluScrnOdeth
Darin Schmidt
Right now just two strands. soon to be 4. Max 800mA min 350mA or close to it. I did notice when I connected a 2.5ohm 5w resistor to it that it dimmed it in the 400 range from around 800 I think. So yeah, 10w 5ohm makes sense. Ill have to look for one of those. Thanks
I'm thinking if I can drop 5-7v that shops be enough
TheFishMan65
New member
4 strings * 800 ma * 7 volts = 22.4 watts
Now you probably won't drop 7 volts at 800 ma since they are inversely related somehow, but you may want more than 10 watts. kcress recommends 5x.
Now you probably won't drop 7 volts at 800 ma since they are inversely related somehow, but you may want more than 10 watts. kcress recommends 5x.
BluScrnOdeth
Darin Schmidt
the pot isnt to control every string, just one for each, is that what you are showing? I see that you have 4 strings * etc, thats why i ask. I was thinking that since a 2.5ohm 5w resistor could drop the current by 3-400mA that if i could find a pot that was similar that might work as well??? But wanted something a little stronger as it only dropped it down to 400 something mA. But i guess that could be good enough as i doubt that anything rewuires such dim light that cant be places in a darker corner or under a rock ledge.
BluScrnOdeth
Darin Schmidt
guess i could try making one of these adjustable voltage regulators if all else fails
TheFishMan65
New member
One pot per string would work.
BluScrnOdeth
Darin Schmidt
TheFishMan65
New member
It all depends on the power drop. I would go higher, but it might work. Figure out how volts you need to drop and at what current.
BluScrnOdeth
Darin Schmidt
Hopefully tonight i'll have my last 2 units complete. I'll take some pics on how i wired this one. Same case design, just that i ran my wiring through some holes to hide the wires so it doesnt look so "crappy".
I also did a DIY thermal epoxy. Bought some ArcticSilver and some reg Epoxy. Mixed it 1:2. Smashed the LED down do that the undercoating had to be super thin. I'll have to test it out when i get home to see how well it worked. I didnt have the patients to order a single bottle of thermal epoxy and wait for it to arrive.
I also did a DIY thermal epoxy. Bought some ArcticSilver and some reg Epoxy. Mixed it 1:2. Smashed the LED down do that the undercoating had to be super thin. I'll have to test it out when i get home to see how well it worked. I didnt have the patients to order a single bottle of thermal epoxy and wait for it to arrive.
BluScrnOdeth
Darin Schmidt
got all the units made, now just got to make the canopy for them.
<img src="http://www.aquatic-refuge.com/RandomPics/led9.jpg" width="600">
<img src="http://www.aquatic-refuge.com/RandomPics/led10.jpg" width="600">
<img src="http://www.aquatic-refuge.com/RandomPics/led11.jpg" width="600">
<img src="http://www.aquatic-refuge.com/RandomPics/led12.jpg" width="600">
<img src="http://www.aquatic-refuge.com/RandomPics/led13.jpg" width="600">
<img src="http://www.aquatic-refuge.com/RandomPics/led9.jpg" width="600">
<img src="http://www.aquatic-refuge.com/RandomPics/led10.jpg" width="600">
<img src="http://www.aquatic-refuge.com/RandomPics/led11.jpg" width="600">
<img src="http://www.aquatic-refuge.com/RandomPics/led12.jpg" width="600">
<img src="http://www.aquatic-refuge.com/RandomPics/led13.jpg" width="600">
BluScrnOdeth
Darin Schmidt
thank you
addonnis242
Member
Very nice build. I'm not sure if this was mentioned before but; what size tank are the 4 fixtures on and what size are the heatsinks you used? Have you had the opportunity to take any PAR readings?
Again very nice build.
Again very nice build.
BluScrnOdeth
Darin Schmidt
the tank is 96x27x25" custom plywood tank (BSOD Plywood tank). the heatsinks i used were 18x8.5". When i had them running at 900mA i was getting little over 360PAR, turned them down to 700mA but i havent done another PAR test yet. I'm going to guess that its close to 300-330 now
TheFishMan65
New member
360 PAR were surface?
