LED Driver
A power supply that regulates current to LEDs, preventing flickering and enabling dimming. Every LED has one — either built into the bulb or as an external unit.
Every LED needs a driver. Without one, the LED would draw too much current, overheat, and die within seconds. The driver sits between mains electricity and the LED chips, converting 120V/240V AC power into the low-voltage DC that LEDs need — and more importantly, regulating the current to keep it stable.
There are two types. Constant current drivers output a fixed milliamp value (350mA, 700mA, 1050mA) and are used in individual fixtures and downlights. Constant voltage drivers output a fixed voltage (12V or 24V) and are used for LED strips and arrays where multiple LEDs share the same power rail.
The driver is usually the first component to fail in an LED fixture — not the LEDs themselves. A cheap driver causes flickering, buzzing, poor dimming performance, and premature death. When a bulb manufacturer cuts costs, the driver is almost always where they compromise. This is why two LED bulbs with identical lumen specs can have wildly different real-world performance.
Specifications
| Constant current | Fixed mA output (350mA, 700mA) |
| Constant voltage | Fixed V output (12V, 24V) for strips |
| Dimmable | Must match dimmer type (TRIAC, 0-10V, PWM) |
Related Terms
- Flicker
Rapid, repeated changes in light output. Can be visible (strobe effect) or invisible but still cause headaches. Usually caused by incompatible dimmers or poor LED drivers.
- PWM Dimming
A dimming method that rapidly switches LEDs on and off thousands of times per second. The ratio of on-time to off-time controls perceived brightness.
- Trailing Edge Dimmer
A dimmer type that cuts the trailing end of each AC wave cycle. Smooth, quiet, and compatible with most LED bulbs — the recommended type for LED dimming.
Mentioned in
Is It Possible To Dim Non-Dimmable LED Lights?
A non-dimmable LED driver can drop from a 25,000-hour lifespan to under 5,000 hours on a mismatched dimmer — and that's the optimistic outcome where it doesn't just flicker and cut out.
Do LED Lights Interfere With Garage Door Openers?
It's not the light itself causing the problem — it's the LED driver's high-frequency switching leaking RF noise straight into the band your garage door opener listens on.
Can LED Bulbs Explode? 2 Main Causes
Capacitors inside an LED driver can stay charged for seconds after switch-off — and that's the least surprising thing about how LED bulbs actually fail.
Are LED Lights Safe For Dogs?
Dogs' flicker fusion frequency sits at 70–80 Hz, so a cheap LED driver can look perfectly steady to you while visibly strobing to your dog. That invisible stress — not the bulbs themselves — is the real thing to fix.
Can You Put A Dimmer Switch On LED Lights? Compatibility Charts
Your dimmer powers the lights at full brightness, but move the slider and nothing changes — that's the LED driver hitting its designed minimum, not a broken bulb.
Why Do LED Lights Make a Clicking Sound? Diagnostic Tool
That click you hear minutes after switching off the lights is a capacitor inside the LED driver slowly charging from leakage current — then discharging all at once.