Introduction
These power LED stars offer an extremely high light output in an energy efficient way. The power LED comes mounted on to special PCB star that acts to draw heat away from the LED, therefore extending its operational life. This makes them perfect for many lighting applications and this sheet explains how.
Technical Information
| Forward Voltage: | 3.5V – 4.0V |
| Angle: | 110 deg |
| Luminus Flux (lm): | 160 – 200 |
| Colour Temp | 6000K – 7000K |
Mechanical Information
Ordering
 |
Description: | |
| 3W Warm white power LED star | ||
| Stock Code: | ||
| 3548 | ||
Using the LED
The LED is a 3W LED and the forward voltage is rated at 3.5V to 4.0V so for the purpose of the calculations a forward voltage of 3.7V is used. The typical current of the LED will therefore be 810mA (from Power = Current x Voltage). The power source used with the LED must therefore be able to deliver at least 810mA. Since most power supplies will be higher than 3.7V a current limit resistor will be required. The next page shows an example of using this LED with a 5V power supply. The resistor also needs to handle 810mA flowing through it and as a result will need to be a power resistor. Please note that during use both the star LED and the resistor will get hot and shouldn’t be touched. The LED has markings for ‘+’ and ‘-’ as indicated below:
Single LED powered by a 5V wall block
 |
Parts List: | |
| 5V wall block PSU | ||
| (2265) | ||
| 3W star LED | ||
| (3548) | ||
| 2.2 Ohm power resistor | ||
| (3009-2R2) |
PLEASE NOTE: The resistor value (and power rating) listed have been calculated for the specific configuration demonstrated in this datasheet. If you make any alterations to the configuration listed, you must ensure that you use a suitably rated resistor of the correct value.
Download a pdf version of this page here 
Learn more about the author read more »