What are the Common LED Dimming Methods?
Canco Lighting specializes in Circular Light design and manufacturing since the year 2008, with practical and accurate lighting solutions to help people create a better space. As technology has evolved to today, LED lighting becomes increasingly popular in homes and businesses, and the ability to control the light output is becoming more important. Dimming is a popular way to control the brightness of LED lights, and there are several methods available. In this article, Canco will share 5 common LED dimming methods including DALI, 0-10V, 1-10V, PWM, and TRIAC.
1. Dimming Principles
1). DALI (Digital Addressable Lighting Interface)
DALI is a digital communication protocol that allows for two-way communication between the lighting control system and the LED driver. DALI dimming uses a 16-bit command to adjust the brightness of each light fixture. DALI dimming can control a single light fixture or a group of fixtures, making it a popular choice for commercial and residential applications.
0-10V dimming is an analog dimming method that sends a voltage signal to the LED driver. The voltage varies from 0 to 10V, where 0V represents the lowest brightness level, and 10V represents the highest brightness level. The LED driver converts the voltage signal into a current signal to adjust the brightness of the LED.
1-10V dimming is a similar analog dimming method to 0-10V dimming, but it uses a different voltage range (1-10 volts) to adjust the brightness of the LED light. The dimmer switch sends a voltage signal to the LED driver, which then adjusts the current to the LED light. This method is widely used in Europe and is often used in combination with a presence detector or a light sensor.
4). PWM (Pulse Width Modulation)
PWM dimming is a digital dimming method that uses a series of on-off pulses to control the brightness of the LED. The LED driver switches the LED light on and off at a high frequency (typically 500 Hz to 5 kHz), and the duty cycle of the on-time determines the brightness level. The frequency of the pulses is usually higher than 100Hz to avoid visible flicker.
TRIAC dimming is an AC dimming method that controls the amount of current flowing through the LED by changing the phase angle of the AC waveform. The TRIAC switch turns the power on and off rapidly, which reduces the amount of power supplied to the LED and dims the light. TRIAC dimming is an older method of dimming that’s commonly used in residential applications.
2. Comparison of Several Dimming Methods
Advantages: DALI is known for its ability to provide smooth, flicker-free dimming and precise control over the light output. It’s also energy-efficient, as it reduces the amount of power consumed by the LED lights.
Disadvantages: high cost, complex wiring, the controller must support the DALI protocol.
Advantages: this method is widely used in commercial and industrial applications, as it’s easy to install and offers smooth dimming， suitable for both retrofit and new installations.
Disadvantages: limited dimming range, voltage drop, and compatibility issues with different drivers.
Advantages: same as 0-10V, better compatibility with presence detectors and light sensors.
Disadvantages: same as 0-10V.
Advantages: PWM dimming offers precise control over the light output, high dimming resolution, no voltage drop, no compatibility issues with different drivers, and high efficiency.
Disadvantages: visible flicker at low dimming levels, electromagnetic interference, and acoustic noise.
Advantages: simple and reliable, low cost, and widely used in home lighting systems.
Disadvantages: not as precise, high harmonic distortion, limited dimming range, and compatibility issues with different drivers or efficient as other methods, and it may produce flicker or noise.
3. Frequently Asked Questions and Answers About Dimming Methods
Q: What about the load of TRIAC dimming?
A: The maximum and minimum load of LED dimmers vary depending on the dimmer and light source used. It is necessary to consider derating to adapt to the spikes caused by the driver. The typical derating percentage should be 25%-30% of the dimmer’s maximum rated load.
Q: What is the actual transmission distance of the 0-10V signal?
A: It is related to the signal wire path, material, power supply signal current, and the number of power supplies. For example, using 1.5mm² copper wire, connecting to an Osram dimming power supply, the transmission distance can reach 500m with a voltage drop of no more than 0.1V.
Q: What if the DALI cannot detect the address of the lamp during the debugging process?
A: Check whether the signal wire is good and ensure that the number of system power supplies does not exceed 64 and that the total bus power supply capacity is sufficient.
Q: Will reversing the 0-10V power signal wire cause damage?
A: No, the power supply will be long bright or long-off, not controlled.
Q: Can I mix different dimming methods in the same lighting system?
A: Yes, it is possible to use different dimming methods in the same lighting system. However, it requires a complex wiring scheme and a compatible controller that supports multiple protocols.