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29

REV:4/2011

LIGHTLINE

AC/DC-Converter

RACD60

Series

Application Information

LEDs are typically wired in series to make a string of LEDs and then the strings can be wired in parallel to generate enough light. If only two or

three strings are wired in parallel then it is recommended to add resistors (e.g. 0.5R) to each string to help balance out the LED currents in each

string. All strings must share a common heatsink for better current matching.

1st LED

Last LED

1st LED

Last LED

1st LED

Last LED

String 1

String 2

String n

A typical 1W high brightness white LED has a forward voltage of around 3.3V at its operating temperature and draws 350mA. Thus each LED

actually draws about 1.15W. Similarly, 3W white LEDs have usually the same forward voltage but can be run at 700mA or more. Using the LED

datasheet specification, the optimum LED arrangement and the best driver for each application can be worked out.

1W LEDS

LED Arrangement

AC/DC Driver

24

2 Strings of 12

RACD60-700

26

2 Strings of 13

RACD60-700

28

4 Strings of 7

RACD60-1400

30

3 Strings of 10

RACD60-1050

33

3 Strings of 11

RACD60-1050

35

5 Strings of 7

RACD60-2100

35

7 Strings of 5

RACD60-2400

36

3 Strings of 12

RACD60-1050

39

3 Strings of 13

RACD60-1050

42

3 Strings of 14

RACD60-1050

42

7 Strings of 6

RACD60-2400

42

14 Strings of 3

RACD60-4200

45

3 Strings of 15

RACD60-1050

3W LEDS

LED Arrangement

AC/DC Driver

12

12 in series

RACD60-700

14

2 Strings of 7

RACD60-1400

18

3 Strings of 6

RACD60-2100

18

6 Strings of 3

RACD60-4200

High Power LEDs

LED Arrangement

AC/DC Driver

Cree CXA2011

Single Array

RACD60-1050

Cree XM-L

6 in series

RACD60-2100

Lumiled Rebel

13 in series

RACD60-700

Osram Dragon

14 in series

RACD60-1050

Bridgelux RS

Single Array

RACD60-2100

Helieon

Single Module

RACD60-1400

Derating Graphs

125

75

50

25

0

100

Ambient Temperature Range (°C)

060 70 80 90

Natural Convection

50

-30

4.2A

All others

40

125

75

50

25

0

100

Ambient Temperature Range (°C)

060 70 80 90

Natural Convection

50

-30

4.2A

All others

40

RACD60

-xxxx/IP67

RACD60

RACD60

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-xxxx/TOF