An electronic circuit that turns AC mains into DC, either constant current for LED modules or constant voltage, often 12 or 24 V, for strips and modules with onboard regulation. It also handles dimming through phase-cut, 0-10V, DALI or DMX inputs, power factor correction and protection. Drivers are the most common point of failure in LED luminaires, and their design decides flicker and low-end dimming performance.
Half the downlights flicker at 10 percent, they're on the cheap drivers, the ones on the spec'd drivers dim smooth to 1 percent.
Also heard as
- LED driver
- power supply
- PSU
Do not mix it up with
- Ballast: A ballast controls current for fluorescent or HID lamps; a driver powers LEDs.
Related terms
LED
Light-Emitting Diode: a semiconductor light source, made white for lighting by coating a blue chip with phosphor.
Ballast
The device that starts and limits current to fluorescent and HID lamps, which would otherwise draw unlimited current.
Flicker
Rapid, repeated variation in light output over time, whether directly visible or not.
0-10V
An analog dimming method in which a low-voltage DC signal from 0 to 10 volts sets driver output.
Dimming curve
The relationship between a dimmer or control signal and the light output it produces.