What an LED Driver Does, and How to Pick the Right Replacement

What is an LED driver?

An LED driver is the power supply built for LEDs: it takes the 230V alternating current from your wiring and turns it into a steady, low-voltage direct current at the exact current the LED chips are designed for, so they light evenly and do not overheat. Every LED light has one, whether you can see it or not.

In an LED bulb the driver is a tiny board hidden in the plastic neck. In a panel light it is usually a separate small box on a short lead, which sits on top of the false ceiling. In a street light or flood light it is a larger unit inside the housing. The LEDs themselves are simple and long-lived; the driver does the hard electrical work, and it works hardest when the supply is poor.

That is why the driver matters to a buyer. When a panel stops working, the cause is very often the driver, not the light board. A separate driver can be swapped for a fraction of the cost of a new fitting. We make five drivers for our own panels, street lights and flood lights at our works in Marol, Andheri East, Mumbai, and sell them as spares so a dead fitting can be repaired rather than thrown away.

Why does an LED need a driver?

An LED needs a driver because LED chips run on low-voltage direct current and are damaged by too much current, while household mains is 230V AC that swings with the supply, so something has to convert the voltage, smooth it and hold the current steady before it reaches the chips.

An LED is not like an old filament bulb, which simply glows hotter when more current flows. Past its rated current an LED heats up, dims over time and fails. The driver acts as a current limiter: it keeps the current fixed even when the mains voltage moves. On our 1041 panel driver the label printed in our catalogue gives the input as 90–240V AC, 50Hz and the output as 40–75V DC at 180mA.

It also does two jobs you never see: it filters the supply so the light does not flicker at mains frequency, and it presents a tidy load to your wiring. Our 1041 label gives a power factor of above 0.95 and an efficiency of above 85%. A cheap driver that skimps here still lights the panel, but it runs hotter and wears out sooner.

Constant current vs constant voltage LED driver: what is the difference?

A constant current driver holds the current fixed and lets the voltage float within a range, which suits panels, downlights and street lights wired as a single LED board, while a constant voltage driver holds a fixed voltage such as 12V or 24V and suits LED strips and modules that carry their own current limiting.

Read the output line on the label to tell them apart. A constant current driver states a current and a voltage range, for example 180mA, 40–75V DC on our 1041. A constant voltage driver states one voltage and a maximum wattage, for example 12V DC, 60W.

The two are not interchangeable. A constant voltage driver connected to a panel board can push far too much current through it and burn it out within minutes. A constant current driver on a strip light will not run it properly. All five drivers we make are for our panels, street lights and flood lights; we do not make strip light drivers.

How do you read an LED driver label?

To read an LED driver label, check five lines: the input voltage range it accepts, the output current and voltage it delivers, the wattage band it suits, the power factor and efficiency, and any safety warning, because those numbers decide whether a replacement will fit your light and how well it will cope with your supply.

Here is how the label on our 1041 panel driver, as printed in our catalogue, reads line by line:

Watt: 9 to 15W the band of panels it suits. V.IN 90–240V AC 50Hz the mains range it accepts. V.out 40–75V DC the voltage window across the LED board. I.out 180mA the fixed current it delivers. PF > 0.95 Efficiency > 85% how cleanly and efficiently it draws power. Output not mains isolated the warning that matters most.

A wide input range is common practice for drivers meant for Indian mains, which dips and swells through the day. The driver line in our catalogue is listed to IS 15885 (Part 2/Sec 13), the Indian standard for LED control gear, under BIS registration R-71026310. Our best LED light brand guide explains how to check an R-number.

Which LED panel driver do I need?

The LED panel driver you need is one whose wattage band covers your panel and whose output current matches the old driver, so a 12W or 15W panel takes a 9W–15W driver such as our 1041, and an 18W to 22W panel takes an 18W–22W driver such as our 1042.

Our two panel drivers map onto the panels in our own catalogue like this. The 1041, 9W–15W, ₹180 band covers our 10W and 15W Ultra Prime panels, the 15W slim panel, the 9W and 15W aluminium casting panels and the 12W and 15W super slim panels. The 1042, 18W–22W, ₹200 band covers our 22W Ultra Prime, casting and super slim panels.

Two cases need care. Our 8W super slim panel falls below both bands, so ask us which driver suits it. And a panel from another maker may need a different current even at the same wattage, so match the mA too, not just the watts. Sizes and wattages of the panels themselves are in our LED panel light size guide.

LED street light and flood light drivers: which band?

An LED street light or flood light driver is chosen the same way as a panel driver, by the wattage band of the fitting, so an 18W to 24W street light takes an 18W–24W driver, a 30W or 36W fitting a 30W–36W driver, and a 50W fitting a 50W driver.

We make three for outdoor fittings, all listed under the same IS 15885 registration: 1043: 18W–24W, ₹240 1044: 30W–36W, ₹360 1045: 50W, ₹400. By wattage, the 1043 band matches our 18W and 24W street lights and the 20W Ultra Prime street light; the 1044 band our 30W and 36W street lights, the 30W Ultra Prime and the 30W flood light; and the 1045 band our 50W street, Ultra Prime and flood lights.

Our 10W and 15W Ultra Prime flood lights and our 100W and 200W fittings fall outside these bands, so ask us for the right driver before ordering spares. A society or factory that standardises on a few wattages can keep one spare per band in its store and fix a dark pole the same day. Prices of the fittings themselves are on our LED flood light and street light price list.

Why does an LED driver fail?

An LED driver usually fails because of heat, voltage spikes and surges, loose or sparking connections, moisture getting into the fitting, or a mismatch between the driver and the LED board, and in most cases the light board it feeds is still healthy when the driver dies.

The common causes, in plain terms:

Heat a driver packed against insulation or a hot ceiling slab runs hotter than it was built for. Electronic parts age faster with heat. Spikes and surges switching of heavy loads on the same line, or a supply that swings, stresses the input stage. Loose connections a loose terminal in the switch board, holder or junction arcs and sends spikes into the driver. Moisture condensation or rain in a bathroom or outdoor fitting. Wrong band a driver run at the top of, or outside, its rated band.

Many of these point back to the wiring, not the light. If drivers on one circuit keep dying, have the circuit checked rather than buying drivers by the box. Our voltage fluctuation guide covers what to do about a supply that swings.

LED driver or LED board: which one has failed?

You can usually tell whether the LED driver or the LED board has failed by the pattern: a light that is completely dead, strobes at switch-on or dims and recovers points to the driver, while a board with some dark patches or single dead chips and the rest lit points to the LED board itself.

A few quick signs, with the circuit off before anything is opened:

Fully dead while other lights on the circuit work: likely the driver. Blinks or strobes likely the driver. One dark patch or dot a failed LED on the board. Driver case swollen or burnt replace it, and find out why.

Flicker on its own has many causes, from dimmers to wiring; we cover them all in why LED lights flicker rather than repeat them here. If several lights on one circuit misbehave at once, the cause is upstream of the driver. A faint glow when the switch is off is a different problem again, covered in our LED glowing when switched off guide.

How do you replace an LED panel driver?

To replace an LED panel driver, switch off the MCB for the lighting circuit, confirm the light is dead with a tester, lower the panel from the ceiling, unplug the old driver from the panel lead, disconnect its mains side, then fit a driver of the same wattage band and output current and reconnect phase and neutral the same way.

Step by step:

1. MCB off, test dead never rely on the wall switch alone. 2. Lower the panel press the spring clips in and ease it down. 3. Note the wiring photograph the mains terminals before you touch them. 4. Swap the driver plug the panel lead into the new driver; it only fits one way. 5. Reconnect L and N tight, with no copper showing. 6. Refit and test restore the MCB last.

Leave the driver resting on the ceiling board with air around it, not buried in insulation. Simple like-for-like replacement is within a careful homeowner’s reach, but anything involving new wiring or a burnt terminal is a job for a licensed electrician. Our phase, neutral and earth guide explains the wire colours.

Isolated vs non-isolated LED driver: does it matter?

It matters for safety during servicing: an isolated LED driver separates the LED side from the mains through a transformer, while a non-isolated driver does not, so on a non-isolated driver the LED board and its wires can carry mains-referenced voltage and must never be touched while the light is powered.

Our 1041 label states Output not mains isolated, which is common in compact panel drivers. It does not make the panel unsafe in normal use, because the LED board sits behind a cover and inside the fitting. It does change the rule for anyone working on it: power off first, always.

Isolated drivers are generally larger and cost more for the same wattage. For a home panel behind a false ceiling, a non-isolated driver installed and serviced properly is common practice. What you should not do is open a panel live to "see whether it lights", or handle a loose LED board on the bench with the driver plugged in.

LED driver price: repair or replace the light?

Replacing a failed LED driver is almost always cheaper than replacing the whole light, because in our range the driver costs roughly a third to a half of a panel and a quarter to a third of a street light, and the LED board it feeds is often still good.

The saving grows with wattage. A 50W street light at ₹1,600 can often be brought back with a ₹400 driver. Replace the whole fitting instead when the housing is cracked, water has reached the board, or several LEDs on the board are dark. VIYONA LED 1045 is a 50W street and flood light driver with an MRP of ₹400.