LED Technology

How to Choose an LED Power Supply: A Practical Guide

March 31, 2026 3 min read
How to Choose an LED Power Supply: A Practical Guide

What Is an LED Power Supply?

An LED power supply (or LED driver) converts household 230 V AC into lower DC voltage (typically 12 V or 24 V) needed to power LED strips and some LED fixtures. Without the right power supply, LED products won't work or will fail quickly.

Key Parameters

1. Output Voltage (V)

Must exactly match your LED product: 12 V DC for shorter strips, 24 V DC recommended for longer runs.

2. Wattage (W)

Power supply wattage should be at least 20% higher than total LED load. Formula: LED wattage × 1.2 = minimum PSU wattage.

3. IP Protection Rating

IP20 for dry indoors, IP44 for bathrooms, IP65+ for outdoor use.

4. Dimming Compatibility

If you plan to dim your LEDs, choose a dimmable power supply compatible with your dimmer type (TRIAC, 0–10 V, PWM, DALI).

Choosing a driver: sizing table

LED stripLengthTotal loadRecommended driver
4.8 W/m, 12 V5 m24 W30–36 W, 12 V
9.6 W/m, 12 V5 m48 W60 W, 12 V
14.4 W/m, 24 V5 m72 W100 W, 24 V
14.4 W/m, 24 V10 m144 W200 W, 24 V (feed from both ends)

Note the last row: runs longer than 5 m must be fed from both ends or split into sections, or the far end will visibly dim from voltage drop.

12 V or 24 V?

At the same power, a 24 V system draws half the current, so losses in the cable and the strip are far lower. Rule of thumb: 12 V for runs up to 3 m, 24 V beyond that. Vehicles, boats and furniture lighting often stay on 12 V for compatibility.

Where to mount the driver

  • Ventilation — leave a few centimetres of clear space; a sealed niche cooks the driver.
  • Access — it is the most failure-prone part of the system, so never seal it into a closed construction.
  • Distance to the strip — keep the low-voltage run short; the 230 V side can be as long as needed.
  • Wet rooms — mount the driver in a dry zone, not beside the strip.

Frequently asked questions

Can several strips share one driver?

Yes, if their combined load stays under 80 % of the driver's rating and the voltage matches. Wire them in parallel, not in series.

Why does my LED strip flicker or buzz?

Usually an undersized driver, an incompatible dimmer, or a cheap driver with high ripple. More in why LED bulbs flicker.

What is the difference between constant voltage and constant current?

LED strips need constant voltage (12/24 V). Constant current drivers (rated in mA) are for LED modules and fixtures — the two are not interchangeable.

Summary

A correct driver means matching voltage, 20 % power headroom, the right IP rating and a location where it can cool. Browse our drivers and LED strips or get in touch — we will size it for your project.

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