How to choose constant voltage led driver and constant current led driver?

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What is constant voltage(CV) and constant current(CC) ?

  • Constant Voltage:

When the rated parameters of the constant voltage circuit are determined, the output voltage is fixed, and the output current change based on the load.
When using constant voltage led driver for LED lights, each string of LEDs need to equipped appropriate resistor to make the brightness of each string is average.

  • Constant Current:

The output current of constant current circuit are fixed, and the output voltage will change based on the load. The smaller the load resistance is, the lower the output voltage is. The bigger the load resistance is, the higher the output voltage is.
When choosing constant current driver, please pay attention to the maximum output current and voltage, it will limit the quantity of LEDs which the driver could work with.

How to choose constant voltage LED driver and constant current LED driver?

  • Under below situation, you could choose constant voltage LED driver:

When the LED lights need fixed output voltage and have built-in resistor or constant current circuit to limit the current range, you could choose constant voltage LED driver.
Due to the circuit design and installation of constant voltage LED driver is well known, so it is relatively simple to design the whole control circuit of LED lighting.
Electric current excite photon make the LED light. The higher the current is, the better the conversion efficiency is. But if the current is too high, it will damage the fixture and shorten the service life. Constant voltage circuit is more suitable for large scale lighting situation, but it is less appropriate for highly illuminated situation, since the ability of constant voltage led driver to adjust brightness consistency is relatively worse.

  • Under below situation, you could choose constant current LED driver:

When the LED lights need fixed output current and specific range voltage, you could choose constant current LED driver.  
The advantage of constant current led drive is that the brightness can be controlled steadily and effectively, and it has consistency in adjusting the brightness of the light make the lamp remains in the best lighting state for a long time.
The lighting control circuit is more complexity, but the output current is fixed, it could prevent fixture from damaged by temperature rising which caused by too high current and it could extend the service life of fixture.

The comparison of constant voltage LED driver and constant current LED driver


Reference:https://www.ledinside.com.tw/knowledge/20110905-16801.html
Reference : https://www.arrow.com/en/research-and-events/articles/product-roundup-led-power-supply
Reference : https://www.ys-led-driver.com.tw/products.php?index=199&c1=34&c2=87
Reference : https://www.ledsupply.com/blog/constant-current-led-drivers-vs-constant-voltage-led-drivers/