Constant current or constant voltage led driver? Which is better?
Constant Voltage and Constant Current LED Systems. It is very important to know the difference between the two different types of LED systems. Constant Current (CC) & Constant Voltage (CV) – each relate to a different circuit wiring configuration. Typically, LEDs are operated (or “Driven”) such that their (average) current is constant (Constant Current), power electronics components (led driver ICs, transformers. etc), are used to create power supply circuits which convert AC voltage into regulated LED constant (average) current.
A constant current power supply varies the voltage across an electronic circuit allowing the device to maintain a constant electric current. This thus ensures that, no matter the variation in voltage, the current delivered to LEDs does not change. In contrast to constant current led power supplies, constant voltage drivers are designed to operate with LED modules requiring a fixed voltage (ac to dc power supply), typically 12 or 24V DC. Modules are connected in parallel across the driver’s output power.
Advantages of using the constant current power supply: More consistent brightness and less light decay due to more stable and reliable output current for driving LEDs, as a result, it is able to have longer lifespan than the constant voltage led driver.
Constant voltage power supply: It is easier to design and develop with engineers and technicians, the cost is lower and the selling price is cheaper.
The constant voltage power supply is usually considered as not so good. During the working with LED lights, there might have the excessive forward current, which will result in extra heat generation and a significant reduction in LED lifespan. Therefore, a constant current source is the preferred method to drive one LED. In fact, LEDs are considered constant current driven devices.