LED the sun shine

Hi All,

Elektor published an LED circuit in the December issue.

Here are some specifications of the LED:

Manufacturer: HUEY JANN (Taiwan)
Name: H50WA-CWS (50W!)
Operating voltage: 27-28VDC
Forward current: 1750mA
1,925 ... 2,725lm depending on colour (warm white to cool white) (2X100W filament type lamp)
Emission angle: 120 degrees
Color temperatures from 3,300 to 8,000K
LED dimensions: 56X40X2.8mm
Max allowable substrate temperature is 130deg/C

The LED was tested using a MEANWELL LPC-60-1750 SMPS, specified
1,750mA at 9..34VDC output voltage
input voltage: 90 .. 264VAC/47 .. 63Hz
total power: 59.5W
efficiency 87%
over current and short circuit protected

I made a PCB design fitting on a 100X100X40mm finned heatsink with a thermal resistance of 1.3K/W.

Although the PCB design is single sided I recommend to use a double sided board to have a large independent heatsink for the power transistor.

The components are placed around the LED with a center cut in the PCB to mount the LED directly on the heatsink.

The LED is dimable with an external 10K pot which connects to a three pin wafer.

Here is the schematic and Eagle board layout.

LED connection is done using appropriate wires from the solder pads to the LED terminals which uses M2.5 screws.


Everbody interested in the schematic and PCB layout might PM me his email address to get the Eagle files.

Regards

Boncuk