Introduction
When selecting an LED power supply, you’ll often come across terms like CV (Constant Voltage), CC (Constant Current), and CV+CC (Constant Voltage + Constant Current).
Understanding these modes is essential for choosing the right power supply and ensuring stable LED performance, optimal brightness, and longer lifespan.
1. Constant Voltage (CV)
A constant voltage (CV) power supply delivers a fixed output voltage, regardless of input voltage fluctuations or load changes (within its rated range).
- Output voltage remains stable (typically within ±1–2%)
- Common voltage levels: 12V, 24V, 48V
- Works best with LED systems that include built-in current control (e.g., LED strips with resistors or driver ICs)
Example:
If a 48V CV power supply is used, the output will remain at 48V, even if the input AC voltage or load varies.
Key Advantages:
- Simple and widely used
- Compatible with many LED strip applications
Limitations:
- Current is not regulated directly
- Requires external current control components
2. Constant Current (CC)
A constant current (CC) power supply provides a fixed output current, while the output voltage automatically adjusts based on the LED load.
- Output current remains constant
- Voltage varies depending on total LED forward voltage (Vf)
- Ideal for directly driving LEDs without additional current regulation
Example:
- 12 LEDs in series, each with Vf = 3.5V
- Total voltage = 42V
- If using a 700mA CC driver, the output will adjust to 42V at 700mA
Key Advantages:
- Ensures consistent LED brightness
- Protects LEDs from overcurrent
- Extends LED lifespan
Limitations:
- Requires precise matching with LED configuration
- Less flexible for mixed or changing loads
3. Constant Voltage + Constant Current (CV+CC)
Many modern LED power supplies combine both modes, known as CV+CC.
How It Works:
- Startup / light load → CV mode (stable voltage output)
- When current reaches rated limit → switches to CC mode
This hybrid behavior allows the power supply to adapt automatically to different load conditions.
Key Benefits:
- Supports both CV and CC applications
- Ideal for direct LED driving or systems with driver ICs
- Offers greater design flexibility
- Simplifies system selection
Why CV+CC Is Important
The CV+CC design is widely used because it can handle:
- LED strips (CV applications)
- Direct LED driving (CC applications)
- Mixed or evolving system designs
This makes it a versatile and reliable solution for most LED lighting systems.
Conclusion
Choosing between CV, CC, and CV+CC depends on your LED setup:
- Use CV for LED strips or systems with built-in current control
- Use CC for direct LED driving
- Use CV+CC for maximum flexibility and compatibility
Understanding these modes ensures better performance, improved efficiency, and longer-lasting LED systems.
If you need help selecting an LED power supply, feel free to contact our team at contact@powersupplymall.com. We provide professional technical support and a wide range of solutions.