Controlling lighting levels in your residential or commercial space allows you to achieve the perfect ambiance based on the times of day or what activities are being performed. Dimming your lighting can also help save energy and reduce energy costs over time. However, with various dimming methods available, it may be difficult to understand the differences between each type. This article explores the mechanisms behind different types of dimmers to help you better understand your lighting system.
TRIAC Dimming
TRIAC dimming is the most commonly recognized dimmer type, with TRIAC dimmers found in most home centers and hardware stores. TRIAC (TRIode for Alternating Current) dimmers modify the voltage waveform to reduce the amount of power input to the device being controlled. Reducing the input power results in a corresponding reduction in a power supply's output voltage/current or a decrease in the lumen output of a light fixture. TRIAC dimmers come in two variations: Magnetic Low Voltage and Electronic Low Voltage.
Magnetic Low Voltage (MLV)
Also known as Leading Edge or Forward Phase Dimming, MLV dimming controls the amount of power delivered to the load by cutting off the leading edge of the AC waveform. This reduces the power supplied and dims the output.
Electronic Low Voltage (ELV)
ELV dimming, also known as Trailing Edge or Reverse Phase Dimming, controls the amount of power delivered to the load by cutting off the trailing edge of the AC waveform. These dimmers can assist with smoother dimming performance, reduced flicker, and reduced hum, especially with electronic low-voltage lighting.
0-10V Dimming
0-10V dimming control works by varying a voltage from 0 to 10 VDC on dedicated dimming wires. The output of a power supply or light fixture is proportional to the voltage applied, with 10V operating at full output and 0V operating at minimum output. Since 0-10V dimming allows for fixtures to be daisy-chained, this method is most commonly found in commercial lighting applications where control over multiple lights is needed.
Pulse-Width Modulation (PWM) Dimming
PWM dimming control adjusts output by rapidly turning the power output on and off at a fixed frequency. This process happens so quickly that the human eye can’t detect the switch between on and off. The proportion of on-time to total time sets the dimming percentage, with a higher on-time resulting in a higher output.
Potentiometer Dimming
Potentiometer dimming varies the output using a variable resistor, or potentiometer, to set the dimming level. As the resistance increases, the current decreases, reducing the output. This dimming method is commonly found in simple setups that require manual control, but it is less suitable for systems with smart control integration or automated dimming.
DiodeDrive is dedicated to providing reliable power supplies for a variety of applications. We offer dimmable AC/DC power supplies using each of the dimming methods mentioned above, as well as power supplies that are capable of supporting multiple types of dimming control.
