What is an LED Driver?

Why LEDs Need Drivers

Unlike incandescent lamps that can connect directly to mains voltage, LEDs are semiconductor devices requiring precisely controlled current to operate safely. Without a driver:

• Excessive current would cause rapid LED degradation and failure • Voltage fluctuations would cause visible flicker • No dimming control would be possible • LED colour and output would drift with temperature changes

The driver is the 'brain' of the luminaire — its quality directly determines light output stability, flicker performance, dimming smoothness, energy efficiency and product lifetime.

Constant Current vs Constant Voltage

LED drivers fall into two main categories:

• Constant current (CC) — delivers a fixed current (e.g. 350mA, 700mA, 1050mA) regardless of the connected LED load. The voltage varies to maintain the set current. This is the standard for most commercial LED luminaires — downlights, panels, linear systems, high-bays. Constant current ensures uniform brightness and consistent LED life.

• Constant voltage (CV) — delivers a fixed voltage (typically 12V or 24V DC) with variable current. Used primarily for LED tape, LED strip lighting and signage where multiple LED modules are connected in parallel across a common voltage rail.

Most EOS luminaires use constant current drivers. Our LED tape and linear accent products use constant voltage.

Dimming Protocols

Modern LED drivers support various dimming interfaces:

• DALI / DALI-2 — digital protocol, most specified for commercial projects. Flicker-free dimming to 1%. • DSI — older digital protocol, largely superseded by DALI • 1-10V — analogue dimming signal. Simple and reliable but limited to basic dimming with no feedback. • Mains dimming (leading/trailing edge) — phase-cut dimming compatible with conventional wall dimmers. Common in residential and hospitality applications. • Wireless (Bluetooth Mesh / Casambi / Plexus™) — driver-integrated wireless control with no dedicated control wiring.

EOS specifies high-quality drivers from leading European manufacturers, ensuring reliable dimming performance, long lifetime and full compatibility with DALI-2 and Plexus™ wireless controls.