Well…. After 4 years with same DIY led lighting system over my tank, I came to the decision that it was finally time to replace it with a new, more efficient system. I knew right off the bat that I wasn’t going to settle for an “off the shelf” product to replace what I had built previously, so I began planning for my new build. To make a long story short- Here’s what I came up with….
(1) 6’ Makers Heat sink kit- purchased from LEDGroupBuy. The heat sink comes with 6 fans and a ton of led mounting hardware. Cost- $300 and change. There’s no better deal out there for a heat sink kit this large.
(2) LED’s- BridgeLux VERO 18’s. This build uses 12 of them to be exact. I used a 50/50 mix of 5500K “Cool White” and 97CRI 2700K “Warm White”. The 2700K leds were chosen for their excellent color rendition rating and help provide more of the “red light” that’s missing in most freshwater led lighting systems. I purchased the leds and their 18”wiring harnesses from DigiKey for approximately $270
I arranged the leds along the heat sink starting with a cluster of 4 “warm” & “cool” at the 3 foot center line.
The remaining 8 leds are mounted in “cool/warm” pairs at 1’ increments from the 3’ centerline.
Here’s a lousy shot that shows the final led spacing-
(3) LED Drivers. Here’s where my build differs from most and gets complicated. I’d originally planned to use the MeanWell LDD-H series of led drivers mounted to custom built PcB’s. The custom PcB’s would have been designed to mount the LDD-H drivers to the top rail of the Makers Heat Sink in an inverted position. I chose something a bit different….
This is a driver that I designed and custom built from scratch. It’s based around the Allegro Microsystems A6211 constant current led driver IC. The driver IC is rated for 48VDC and up to 3000ma. I designed the driver board to include these features…
1) 5 independent channels.
2) 4 user adjustable current levels for each channel. Each channel can be set to provide 300, 700, 1000, or 1400ma output.
3)12V/5V on board power. No need for separate 12V & 5V power supplies or
their associated wiring to provide power for cooling fans or led dimming controllers. This Driver board contains a mounting spot for a MeanWell SCW05C-12 DC/DC convertor. The SCW can drop 48V to 12V and provide up to 470ma for powering cooling fans and feed to an on board 5V regulator.
4) 2 cooling fan output connections with transistorized control. Each connection can be utilized for PWM speed control of 2,3, & 4 wire PC cooling fans.
5)On Board Atmega328 Microcontroller prewired to each driver’s PWM input and to the Cooling fan connection points.
DS1307 Real time clock & battery backup.
2 Dallas OneWire Temperature probe connections with built in PullUp circuitry.
2 I2C Enabled Device connection points with built in PullUp circuitry.
1 FTDI Connection point for programming purposes.
Here’s a photo showing the Atmega328 and the copper heat sinks for cooling the A6211 led drivers.
I built 3 driver/controller PcB’s for this project and mounted them between the 6 cooling fans that came with the Makers Heat Sink kit. Each Driver/ Controller powers 4 Led arrays and two cooling fans. A single pair of wires run to a 48VDC/7.3 amp Power supply runs the whole show.
Here’s a photo showing one of the driver boards nestled between two fans-
Here’s a shot that I took while test firing the new system and checking the LCD for proper readout.
Here’s a shot in the dark showing the new system under test while straddling a couple of saw horses.
I programmed each of the driver/controllers with the same coding so they all operate independent of one another. The new system has been over my tank for 5 days now and is working beautifully. I’ve played around with the current settings for the Led’s to get the best color temp/rendition and I’m happy with the results. I currently have all 6 “cool whites” being driven at 1000ma and the “warm white” at 300ma. The resulting light is a nice white, while still showing the red coloration of my Ludwigia Inclinata Var. “Cuba”
I’ll get some pictures up…… just as soon as I get a new camera. The one I had got dropped while taking the shots I posted earlier in this thread. LOL