What is an LED driver?
The electronics that power an LED module. They turn the supply from the isolation transformer into the steady current the LEDs need, and follow the circuit’s brightness steps.
An LED cannot run straight from the airfield circuit. The LED driver sits between the isolation transformer and the LED module and gives the LEDs exactly the current they need.
1It converts and regulates
The driver takes the AC supply from the secondary circuit, rectifies it to DC, converts the power and regulates the current to the LED module. Steady current gives steady, predictable light.
2It follows brightness and protects
On a series circuit the current is stepped to change brightness. The driver is built so the LED output follows those steps, and it includes surge and fault protection against lightning transients, overheating and faults in the module. The driver must also suit the CCR type: a thyristor CCR delivers a chopped current waveform, and a driver not designed for it can flicker or load the circuit unevenly.
3Keep it cool and dry
Driver electronics are sensitive to heat and moisture, so the driver is often sealed or potted and passes its heat through a thermal pad into the body. Look for dark or flickering output, heat marks, moisture and poor connections, and replace with the correct type, mounted as specified.
| Element | Detail |
|---|---|
| LED driver | Electronics that power the LED module from the transformer secondary |
| Stages | Rectify, convert, regulate current, protect |
| Fed by | The secondary circuit of the isolation transformer |
| Feeds | The LED module, at a controlled current |
| Brightness | Follows the circuit current steps so intensity changes as intended |
| Check | Dark or flickering output, heat marks, moisture, connections, thermal contact |
| Reference | FAA AC 150/5345-46 · FAA EB 67 · ICAO Annex 14 Vol. I, App. 1 and 2 · manufacturer data |
Frequently Asked Questions
Q1What is the LED driver in an airfield light fixture?
The electronics inside an LED fixture that take the supply from the isolation transformer secondary and convert it into the steady, controlled current the LED module needs.
Q2Why does the driver matter for brightness?
LED output follows the current it receives. The driver sets that current, and in a series circuit it follows the circuit’s brightness steps so each fixture changes intensity as intended.
Q3What are the signs of a failing driver?
A fixture that is dark, flickering or dim while the LED module looks sound, signs of overheating, moisture or burn marks, and repeated failures. Replace the driver with the correct type, mounted and cooled as specified.
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