Dimmable Power Supply

Choosing the correct LED power supply for LED strip lights requires five steps:

Step 1. Confirm your LED strip voltage
Your strip will be either 12V DC or 24V DC.
The LED driver or power supply must match this voltage exactly.

Step 2. Calculate total wattage
Watts per foot × total installed length.

Example
5W per foot × 20 feet = 100W total load.

Step 3. Add 20 percent headroom
100W × 1.2 = 120W
You would select a 120W LED driver or LED power supply.

Step 4. Choose installation style
Do you need a junction box LED driver, plug in LED power supply, or fly wire driver?

Step 5. Determine if you need dimming
If you want dimming, you must choose a dimmable LED power supply that matches your control method.

Once voltage, wattage, dimming type, and installation method are confirmed, selecting the correct LED strip power supply becomes straightforward.

When selecting a dimmable LED driver or LED power supply, first decide how you want to control your LED strip lights.

There are three main dimming options:

1. Phase Cut Dimming
   Also called TRIAC, ELV, MLV, or inline AC dimming.
   Works with standard wall dimmers.
   Common in residential retrofit installations.
   The LED driver must be labeled phase dimmable.
2. Low Voltage PWM Dimming
   Uses a controller installed between the LED power supply and the LED strip.
   Ideal for RGB LED strips, tunable white strips, and multi zone systems.
   Smart app control falls under this category because it uses a low voltage controller.
3. 0 to 10V Dimming
   Primarily used in commercial lighting systems.
   Requires two additional control wires.
   Not compatible with standard residential wall dimmers.

Choosing the wrong dimming method is one of the most common LED power supply mistakes. Always match the dimmer to the LED driver specification.

The correct LED driver style depends on the installation type and electrical requirements.

Junction Box LED Driver
Hardwired with integrated electrical enclosure.
Code compliant for permanent installations.
Common in contractor and new construction projects.

Plug In LED Power Supply
Includes AC input plug.
No electrician required.
Ideal for under cabinet lighting and furniture installations.

Fly Wire LED Driver
Bare AC input and DC output wires.
Flexible for custom enclosures or concealed installations.

Selecting the correct LED power supply format ensures a clean, safe, and compliant installation.

Yes, as long as:

• All LED strips are the same voltage
• Total wattage stays below the LED power supply rating with 20 percent headroom
• LED strips are wired in parallel

Never wire constant voltage LED strips in series. This can cause uneven brightness and system failure.

For larger LED strip installations, proper power distribution is essential.

If the LED driver or LED power supply is undersized:

• Lights may flicker
• The power supply may shut off intermittently
• The driver may enter protection mode

Most quality LED power supplies include built in overload protection.
If overloaded, the driver will automatically shut down temporarily instead of permanently failing.

However, continuous overload reduces lifespan and performance.

Always size your LED driver with at least 20 percent headroom.

LED strip lights operate on low voltage DC. Low voltage systems are sensitive to distance.

As distance between the LED driver and LED strip increases, voltage drop occurs. Voltage drop reduces brightness at the far end of the strip.

Voltage drop depends on:

• System voltage, 12V drops faster than 24V
• Wire gauge
• Current draw
• Distance from power supply to LED strip

Basic voltage drop formula:

Voltage Drop = 2 × Distance × Current × Wire Resistance

Practical guidelines:

• Use 24V LED strip systems for longer runs
• Increase wire gauge for longer distances
• Inject power at multiple points
• Keep the LED power supply as close as practical to the load

If brightness fades toward the end of the LED strip, voltage drop is typically the cause.

In most applications, 24V LED strip systems perform better.

24V advantages:

• Lower current for the same wattage
• Reduced voltage drop
• Longer continuous runs
• Improved overall efficiency

12V LED strip systems are typically used for shorter runs or when replacing an existing 12V installation.

For new LED strip projects, 24V is generally recommended.

Choosing the correct IP rated LED driver or LED power supply is critical for safety and durability.

Indoor Dry Location
Use IP20 or IP23 rated LED power supplies.
Suitable for cabinets, ceilings, and enclosed indoor areas.

Outdoor or Damp Location
Use IP65, IP67, or IP75 rated LED drivers.
Required for outdoor installations or exposed environments.

IP ratings indicate environmental protection:

IP20
Dry indoor use only.

IP65
Dust tight and protected against water spray.

IP67
Protected against temporary immersion.

Always match the LED power supply IP rating to the installation environment to ensure long term reliability.