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LED Drivers: The Ultimate Guide

Are you into energy-saving electronics? If yes, then you know LED light bulbs have great energy-saving abilities and a long life span. But most people don’t know that the LED PCB light bulbs require specific devices to operate—called LED drivers. Hence, they are similar to the ballasts found in low-voltage bulb transformers or fluorescent lamps.

Therefore, they are responsible for the electricity that feeds into the LEDs.

But LED drivers could be a tricky technology because there are various types. And it’s a bit overwhelming most times.

That’s why we’ll be talking extensively about LED drivers in this article. Are you interested in finding out more about this topic?

Then, stick around a little while.

What Is an LED Driver?

 LED lightning power supply isolated on white background

LED lightning power supply isolated on white background

Simple. It’s an electrical component that controls the power of an LED, or multiple layer LED PCBs. In short, it’s a vital part of an LED circuit. Thus, operating without an LED driver means doom for an LED system.

LED drivers are the ideal go-to if you want your LEDs to last long. How? They help to safeguard LEDs from high-temperature mishaps or high-power faults.

As a self-contained power supply with similar features as LEDs, an LED driver helps to prevent thermal runaway. Plus, it makes up for the forward voltage changes that occur while offering a stable current.

What Are the Benefits of LED Drivers?

Led lights panel

Led lights panel

LEDs run on a low voltage between 12 – 24 volts for direct current. So, even if you’re running on a high voltage between 120 – 277 volts on AC, an LED driver will rectify the current. In short, it helps to step down alternating current to direct current. Or even balance high voltage to low voltage.

LED drivers keep LEDs from current or voltage instabilities. Voltage changes in LEDs could lead to a fluctuation in the current supply. That’s why the output for LED lights is proportional to their supply. And LEDs have a certain rating to operate within a specific range. Hence, too little or too much current will cause the light output to vary or damage quickly because of higher temperatures in the LED.

Overall, the LED drivers have two main benefits:

1. It helps to translate AC to DC.

2. The drivers are useful for maintaining the current or voltage flowing through a circuit without going below its rated level.

When Does an LED Driver Become Necessary?

Lighted diodes on reel LED tape, and voltage converter

Lighted diodes on reel LED tape, and voltage converter

Generally, every LED light source needs an LED driver. However, the main question should be; “do I need to buy one separately?” The thing is, some LEDs come with an integrated driver in the bulb. Plus, LEDs created for home use, most times, come with LED drivers. And a great example is bulbs with GU24 / GU10 or E26 / E27 bases—running on 120 volts.

But low voltage LEDs like; tape lights, MR-bulbs, outdoor-rated lights, panels, and certain light fixtures, need an LED driver to perform well.

So, the short answer is:  when you’re dealing with low-voltage LEDs—you need LED drivers. But we can’t say the same thing for household LED bulbs running on 120 volts.

Types of LED Drivers

A closeup of the led Strip on plastic spool attached to current converter

A closeup of the led Strip on plastic spool attached to current converter

Every LED driver listed here operates with specific electrical requirements.


This LED driver only needs a range of output voltages and a fixed amount of output current. Constant-current entails a specific output current—labeled in milliamps or amps with an array of voltages that vary on LED’s load/wattage.


Constant-voltage LED drivers involve a fixed output voltage alongside a max output current. Plus, this LED’s current comes with a regulated system powered by an internal constant-current driver or simple resistors—wrapped in the LED module.

Also, they only need one stable voltage, which is usually 12- or 24-volts DC.

AC LED Drivers

This type of LED driver technically runs incandescent or low-voltage halogen bulbs. Hence, they have no-minimum load transformers. But, the AC LED drivers can’t work with conventional transformers because of their inability to detect low voltage.

Dimmable LED Drivers

These LED drivers enable you to dim your LED lights. Plus, it permits the dimming of constant voltage LEDs. And it achieves this by reducing the amount of leading current going to the LED bulb.

Applications of LED Drivers

Mounting new technology special led ceiling lamp

Mounting new technology special led ceiling lamp

Automotive LED Drivers

LED drivers

You can distinguish your vehicle interior and exterior lighting system with quality automotive LED drivers in the various areas:

  • Infotainment and Cluster
  • Anterior Headlights
  • Rear light and interior lights

Backlight LED drivers

LED drivers

The backlight LED drivers tend to use a specific dimming system for LCD panel backlighting.

Illumination LED drivers

LED drivers

With illumination LED drivers, you can establish infra-red illumination for your electronics. Plus, it’s achievable with a multi-topology constant-current controller.

RGB LED drivers


RGB LED drivers help to add an indication feature or animation to your polychromatic LED arrays. Plus, they are usually compatible with a range of common interfaces.

LED display drivers

LED display drivers

You can regulate specific LED strings with low and high-power consumption thanks to the LED display drivers. So, whether it’s a large narrow pixel or a matrix solution for micro or mini LED digital display signage applications—these drivers work.

How to Choose the Right LED Driver?

Led panels driver

Led panels driver

Consider these factors before choosing an LED driver:

DC Dimming

Do you prefer dimmable LEDs? Or do you plan to change its brightness? Then, opt for a dimmable power supply or driver. Why? It’s easy to spot them from the specifications of the power sources. Plus, you’ll find other things on the specification table, like the drivers’ compatible dimmer control types.

Power Requirements

The voltage needs of your light are one of the first things to consider. So, if your LED needs 20 volts to operate, get a 20-volt driver.

In summary, the goal here is to ensure that your driver obtains the right power output. And the rule of thumb is; your output should be within the specified range of your light.

Also, for a constant-voltage driver, you can consider the voltage range. But if you have a constant-current driver, you can consider both current and voltage range.

In short, take note of the voltage supply of the proposed LED light. Hence, ensure the LED driver accepts the input voltage of the LED. That way, it’s easy to step down to the adequate output voltage.

Also, you need to consider the wattage. While you’re at it, ensure to get a driver with a higher max wattage compared to the light’s wattage.

Power Factor

The power factor helps to deduce the power load of the driver placed on the electrical network. And it usually ranges between -1 and 1. So, the standard for power factor is about 0.9 or above. In other words, the efficiency of the driver is higher when it’s closer to one.


There are different standards to look out for with your LED drivers. For instance, we have the UL class 1 and 2. The UL Class 1 is for drivers with high-voltage output. Drivers in this category need safety precautions within the fixture. Plus, it can accommodate more LEDs—which makes it more efficient.

The UL Class 2 drivers don’t need major safety protection at the LED level. Plus, it meets the terms of standard UL1310. Even though this class is a safer option, it has limitations with the number of LEDs it can operate.

The IP rating is another type of safety that shows you what a driver’s enclosure offers. For example, if you see an IP67 rating, it means the driver is safe from dust and temporary immersion in water.


This factor is important as it tells you how much input power the driver has to power the LED. The value expresses in percentage. So, you should expect efficiencies between 80-85%.

LED Driver Calculator

To calculate an LED driver is easy. Simply multiply the wattage by 1.2. 

In essence, if you have 10 LED lights that use 5 watts each, it means the combined wattage usage is 50.

So, to calculate the LED driver, you’ll multiply the total wattage by 1.2. 

It looks like this:

50 x 1.2 = 60.

As you can see, for the above example, the calculated LED driver is 60v–the required power supply needed to handle the 10 LED lights.

How Does an LED Driver Circuit Work?

led driver Board with connection wires without housing

led driver Board with connection wires without housing

The LED driver circuit starts with an AC capacitor. Thus, the capacitor connects with the main supply in a line. Afterward, a resistor of 390KΩ connects with the capacitor in parallel.

This arrangement helps to discharge the capacitor when there’s no supply. After that, another resistor of 10KΩ connects between the rectifier and main supply. When this happens, the full-wave bridge rectifier helps to change the current. Next, the LED converts incoming AC voltage to DC. Then, a capacitor of 4.7µF filters the bridge rectifier output. A Zener diode helps to control the output of the full-wave bridge rectifier. Then, a capacitor of 47µF filters the Zener output. So, the filtered Zener output moves to the LED.

LED Driver Troubleshooting

LED driver troubleshooting occurs when it fails prematurely. When this happens, you may need to replace the LED driver.

LED Driver Replacement

Before you replace an LED driver, ensure the driver is serviceable. Then, confirm that the new driver functions exactly like the original. In other words, it should have the same characteristics as the original.

That way, it will fit into the same space and function perfectly. This step is necessary because a mismatch can result in safety or performance issues.

How to Test an LED Driver?

You can test an LED driver in the following ways:

With resistors for loading

With electronic loads in CV (Constant Voltage) mode

Using LEDs

Regardless of the method you choose, it’s ideal to note that each process has different cons.


How long do LED drivers last?

Typically, LED drivers last for three years.

Is an LED driver the same as a transformer?

No. an LED driver is different from a transformer. And it’s due to their load and output compatibility. For instance, the LED drivers output DC. While transformers output AC.

Can you use an LED driver as a power supply?

Yes. You can if you get an LED driver whose output voltage gives a constant-voltage.

How can you connect an LED driver to power?

Ensure the LED light has the same power as the transformer. Then connect the red and black wires on the led driver to the power source.

What is the difference between the LED driver and power supply?

An LED driver helps to control the current output. In contrast, the power supply offers a constant-voltage.

Closing Words

LED drivers are a thing now. And it’s no surprise because it’s the controlling circuit that helps LED lights operate correctly.

But, before you get an LED driver, consider the factors mentioned in this article. That way, you’ll be free from safety hazards.

Do you have any questions to ask concerning LED drivers? Contact us now!

Hommer Zhao
Hi, I am Hommer, the founder of WellPCB. So far, we have more than 4,000 customers worldwide. If you have any questions, you can feel free to contact me. I really appreciate any help you can provide.