Pi for dimming Cree star LEDs: Check my build list? Also questions. - The Planted Tank Forum
 
LinkBack Thread Tools Display Modes
post #1 of 3 (permalink) Old 06-22-2018, 11:20 PM Thread Starter
Algae Grower
 
PTrader: (0/0%)
Join Date: Jun 2018
Posts: 23
Pi for dimming Cree star LEDs: Check my build list? Also questions.

I want to build a DIY LED lamp for a high tech planted aquarium, and have it PWM controlled for dimming with the Pi. Eventually I want to control as much as I can with the Pi on the tank, but starting with the light.

I am copying the LED setup that the AI Prime uses: Prime Freshwater » AquaIllumination® but upgrading to cree G3 instead of G2. Is there any reason I should stick with G2, I see the G2 are "up to" 1.5amp and the G3 are "up to" 2 amp.

For drivers, do I have the right ones selected? 1.5 and 1 amp high voltage.

How big of a power supply will I need?

Build list: https://i.imgur.com/WYEH6fI.png

I also want to put a temperature sensor on the heatsink to turn on/off and speed up a fan on the heat sink. I read something about a SCW driver to control this, can anyone give me some info on how that works?
UAVgeek is offline  
Sponsored Links
Advertisement
 
post #2 of 3 (permalink) Old 06-22-2018, 11:55 PM
Wannabe Guru
 
PTrader: (0/0%)
Join Date: May 2017
Posts: 1,703
Have fun. Looks good.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.



To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
ChrisX is online now  
post #3 of 3 (permalink) Old 06-23-2018, 02:53 PM
Planted Tank Guru
 
PTrader: (0/0%)
Join Date: Jun 2013
Location: WI
Posts: 11,053
You take the V(f) of the diodes AT the drive current x number of diodes to get the ps voltage needed.
Use largest one and add 3v (just for voltage calc, not watts) if using Ldd's

Each one will differ by "bin" in electrical characteristic's slightly though but an example:
CREE xp-g3
6 x 2.97v (@1500) = 17.82V + 3 = 20.82V
Biggest string so you need a 24V power supply

Take that x the drive current in amps to get the wattage per channel.
17.82 x 1.5 = 26.73W


Add channels up
17.82 x 1.5 = 26.73W
4 x 2.97 = 11.88 x 1.5 = 17.82W
ect..

Multiply x 10% and that is the watt rating of the ps.=

17.82 + 26.73 + (to make it easy) (3 x3= 9W (red will be 2v ish, blue 3.x ish ect) =53.55W x 1.1 (or more if you want to add room for expansion) = say 60W (2.5A)
ACCURATE-ist way short of measuring actual light parameters

Or just add up the driver amps 6A and at 24v 144W
Sloppy way but most likely no errors or surprises ..

"A man with a watch knows what time it is. A man with two watches is never sure."
jeffkrol is online now  
Reply

Tags
None

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the The Planted Tank Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in










Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome