To control the brightness of your white LED lighting using an in-wall AC dimmer switch like those you might already have elsewhere in your home, you need an AC-dimmable power supply.
Installed between a dimmer switch and the LED lighting, these units are intended for direct connection to 120VAC household wiring. Most common dimmers can be used, but a C-L dimmer, which has features specific to LED lighting, is recommended.
Select a power supply with wattage equal to or greater than the total wattage of your lighting arrangement. Not for use with color-controlled lighting. cETLus listed.
LED Tape Lighting
For tape lighting, the power requirement is determined by the wiring configuration, the LED density (# LEDs/m) of your chosen lighting and the length of the lighting. The PDF charts under the specifications tab show totals for the tape lighting (at full brightness) in various wiring configurations.
A straight-run layout uses single or multiple strips in series powered only at one end of the LED strip. A center-feed layout powers two equal legs of tape lighting from a central position; a loop-back layout has both ends of the LED tape powered simultaneously. Array layouts have several unequal lengths of tape powered from one end. Do not include the length of connecting wires when referencing the chart.
For long lighting runs, an array-based wiring configuration, makes the best use of the capacity of the larger power supplies. For installations combining tape lighting and individual LED lights, the power supply should be chosen based on the sum of the two power requirements.
For Individual LED Lights
For all individual (non-tape) LED lighting, the appropriate power supply wattage is determined by the number of lights being used and their wattage at full brightness. For example, a 24-watt power supply effectively runs up to 6 of the 4W white downlights.
Exceeding the power supply’s capacity will cause the lights to flicker or appear dim. The PDF charts under the specifications tab indicate the maximum number of individual LED lights that can be installed per power supply.