Power supply method for the dimming module

Dimming modules are powered by specialized dimmable LED drivers that adjust output voltage or current based on the dimming signal, using either analog or digital control methods.

Overview of Dimmable Power Supplies

A dimmable power supply (LED driver) is designed to regulate the voltage or current delivered to LEDs according to a dimming signal. Unlike standard constant-voltage supplies, these drivers include signal sampling, phase control, and filtering circuits to ensure smooth brightness adjustment, energy efficiency, and compatibility with smart lighting systems . They can work with wall dimmers, smart modules, or control interfaces depending on the dimming method.

Common Power Supply Methods

1. 0-10V Analog Dimming
   • Uses a low-voltage DC control signal (0–10V) to adjust LED brightness.
   • The LED driver acts as a current source, while the dimmer acts as a current sink.
   • Wiring typically includes two high-voltage AC wires for power and two low-voltage control wires for dimming .
   • Full brightness occurs at 10V, and minimum brightness or off occurs at 0V, depending on driver design .
2. PWM (Pulse Width Modulation) Dimming
   • The driver switches the LED current on and off at high frequency.
   • Brightness is controlled by the duty cycle of the PWM signal (e.g., 50% duty cycle = 50% brightness).
   • Provides linear dimming and prevents color shift across the dimming range .
3. Phase-Cut Dimming (Triac/ELV)
   • Triac (leading-edge) or ELV (trailing-edge) dimming adjusts the AC waveform conduction angle.
   • Compatible with traditional wall dimmers.
   • Triac dimming is common in residential applications, while ELV offers smoother dimming and lower noise .
4. Digital Control Interfaces
   • Some drivers use SPI, DALI, or other digital protocols to program dimming levels.
   • Allows precise control of multiple channels and integration with smart lighting systems .

Key Considerations

• The driver must match the dimming method; a 0-10V driver cannot be dimmed with a Triac dimmer.
• Power supply wiring must separate high-voltage AC input from low-voltage dimming control signals.
• Open-circuit or disconnected control wires typically default the LED to full brightness in 0-10V systems .
• Analog dimming may have linearity limitations at very low currents, while PWM provides a wider linear dimming range . In summary, the power supply for a dimming module is a dimmable LED driver that can source or regulate current/voltage according to the chosen dimming method, whether analog (0-10V), digital (PWM, SPI), or phase-cut (Triac/ELV), ensuring smooth, flicker-free, and energy-efficient lighting control .