A year or two ago, members of the online reef community got together to address a point of growing concern amongst would-be LED upgraders. This concern is the so-called “disco ball” effect that occurs when multiple light sources (read: LEDs) originate from different points, which is typically the case for traditional LED fixtures. Enter the multichip LED. These LED chips cram tens to hundreds of LEDs on a single chip, closely approximating a single point light source. Additionally, using multichips reduces the need to mount a bunch of individual LEDs on a heat sink fixture. The DreamChip was envisioned to be a full-spectrum solution for reef tanks on a single chip. It contains white, royal blue, and violet/UV LEDs all on a single chip, breaking out the LED strings in 5 individually controllable channels.
We wanted to have full control over each of the 5 channels, so we paired the DreamChip with one of our LDD-5 Driver Boards and of course a 6-channel Storm LED Controller. This combination of controller and driver should allow full control over the DreamChip.
Running at full tilt this beast is insanely bright. It’s too bright to look at powered up to merely 2% duty cycle. It also throws off a lot of heat. Passively cooled, I don’t think that this heat sink is good enough to cool the DreamChip sufficiently. The current setup has a 6″ x 9″ heat sink that has a base that is about 1/4″ thick, and the chip is mounted properly using Arctic Silver 5 thermal compound as well as #4-40 socket cap screws with nylon washers to distribute the load. Even with this proper mounting and thermal interface, it takes about a minute to get too hot to handle. Luckily this is just a demo setup so it won’t be running this way for long.
The chip is rated for a maximum of 1,400mA per channel. While we do have access to 1,400mA drivers, we decided to use the LDD-5 board for simplicity. Here we’re limiting the current to 1000mA via driver selection of Meanwell LDD-1000H drivers. Running at 1000mA per channel (x5) with a 36V forward voltage, that gives a total power consumption of 180W. Even though these EpiLED and EpiStar individual LED components aren’t as efficient as say Cree XM-L, it is still an amount of light to be reckoned with. The LDD drivers are impressive to say the least, with no discernible heat emanating from the fully potted package.