With all the different variations of LED power supplies, finding the right LED driver for your LED lighting installation can be more difficult than you may think. There are many factors to consider when looking for the best solution that meets your specific installation needs. If you need help finding the best power supply for your installation, please refer to our LED Power Supply Buying Guide. Understanding the power requirements is an important start but understanding the difference between Constant Current and Constant Voltage can help you avoid costly mistakes.

Constant Voltage

Constant voltage LED drivers are designed for a single DC (direct current) output voltage. The most common examples of these types of power supplies are 12VDC or 24DC. LED lights will often specify the voltage they are rated for. Constant voltage LED power supplies are powered by standard line voltage (120VAC), which is the typical output found in wall outlets in a home. These types of LED power supplies convert the alternating current voltage (VAC) to a significantly lower direct current voltage (VDC). However, the voltage will always remain consistent (either 12V or 24V) regardless of the current load. Constant voltage drivers are best for installations where longevity and efficiency are needed.

Constant Current

Constant current LED power supplies are designed with a fixed output current and a variable range output voltage. These drivers work by fluctuating the voltage along an electronic circuit; this allows the current to remain constant throughout the LED lighting installation. With a higher current rating, LED lights will seem brighter, however if unregulated, the LEDs will draw more current than it is rated for. This will result in a drastically reduced LED life-span and premature burn out due to excessive heat. While constant current is great for high power LEDs, because of the increased brightness, these LED power supplies tend to decrease the life of the LED system.

Which is best: Constant Voltage or Constant Current?

Why Constant Voltage?

Constant voltage on the other hand tends to be slightly more expensive are far more energy efficient and use higher rated electrical components. The LED drivers using constant voltage are far better at heat dissipation and require an extra circuit to deliver the appropriate wattage to the LED lighting system. These factors result in a more efficient and longer-lasting LEDs. These power supplies specifically designed to be used with LED tape light, strip lights, puck lights and LED linear bars. Ultimately, constant voltage LED drivers pair perfectly with undercabinet LED installations as they are the most energy efficient and protect the lifespan of the LEDs.

Why Constant Current?

Constant current LED power supplies work best with high powered or very large LED lighting installations, not typically found in homes. These types of LED drivers are great for high powered LEDs or if LED lifespan is not a concern. As previously stated, these power supplies allow for brighter LEDs, but because the current is unregulated. Without a current limiting device, the LEDs draw more current, which increases temperatures, hotter LEDs means less efficiency and a shorter lifespan.