cui.com

date

07/18/2012 │ page 4 of 5

CUI Inc

│ SERIES: VLED15 │ DESCRIPTION: LED DRIVER

DIMMING RANGE

When operating with an incandescent dimmer, the RMS output current shall vary depending upon the

conduction angle and RMS value of the applied AC input voltage. The following graph shows the typical output

versus conduction angle at various line voltages.

The specified dimming range shall be from 30 degrees through 147 degrees conduction angle. Operation

throughout this dimming range shall be monotonic and produce a smooth transition of light output in both

directions of the dimming range. At 120 Vac or 240 Vac input, the driver shall achieve full rated output

current at less than 147 degree conduction angle.

Typical Io vs Conduc on Angle

0

0.2

0.4

0.6

0.8

1

1.2

0

204060

80

100

120

140

160

VAC Conduc on Angle (Degrees)

100V (200V)

115V (230V)

132V (264V)

DIMMING REQUIREMENTS

Dimming of the driver shall be possible with standard triac based incandescent dimmers that chops the AC

voltage as shown below or with Electronic Low Voltage dimmers that employ reverse phase control.

During the rapid rise time of the AC voltage when the dimmer turns on, the driver shall not generate any

voltage or current oscillations and inrush current shall be controlled. During the on time of the AC input, the

driver shall regulate the output. The RMS value of the driver output current shall be proportional to the on

time of the AC input voltage. Care must be taken to assure that the minimum load requirements are met.

Multiple drivers/LEDs may be connected to the dimmer in order to meet the minimum load requirement.

Chopped AC Input to Driver

AC Wall Power