For lighting fixture control, in addition to the switching requirements, led dimmable down lights are also an important component. In the process of lighting consumption of electricity, in the case of no need to turn off the lighting can save energy, but in some time and scenario requirements, if the light can be adjusted to a darker degree, it is also possible to obtain effective lighting energy-saving effect.
The current dimming method of LED lighting commonly has the following two, silicon controlled dimming and wavelength control dimming (Pulse + Width + Modulation, referred to as PWM).
Thyristor, also known as silicon controlled, is a semiconductor device. Thyristor dimming is a continuous regular change in current during an alternating current cycle. For one, the A and C poles need a minimum sustaining current. For two, the control pole G needs to provide the trigger current to trigger the conduction. In this way, we can control the arrival of the trigger current time to cut the phase angle and control the proportion of time that the light bulb is on in a time cycle to regulate the light bulb.
Wave Width Control Dimming, Pulse+Width+Modulation, (PWM). The two ways of carrying information nowadays are analog signals, a series of continuously changing physical quantities represented by information, and digital signals, signals with only two states, similar to computer science, with only two types of zeros and ones. The conversion between the two uses the familiar PWM technology.
When performing pulse width PWM dimming, an additional pulse width adjustment signal source needs to be provided. By changing the input pulse signal percentage to control the proportion of time between light and off in a period, and then achieve the purpose of controlling the brightness.
Cut-phase dimming, which is essentially silicon controlled dimming, is recommended for full voltage lamps, similar to incandescent, halogen, metal halide, etc. Of course, the silicon controlled dimming program for LED lamps is also the mainstream on the market today. For LED lights to be dimmed by SCRs, for example, their power supply must be able to analyze the variable phase angle output of the SCR controller in order to adjust the constant current flowing to the LED in one direction. Doing this while maintaining proper dimmer operation is very difficult and often results in poor performance. Problems can manifest themselves as slow start-up, flicker, uneven light, or flicker when adjusting light brightness. In addition, there are problems such as inconsistencies between components and unwanted audio noise from the LED lights. So LED lamps and lanterns if you use the cut-phase dimming method, lamps, drivers, and control system matching test is very important.
0/1-10V dimming, essentially PWM dimming, through the voltage change on the signal line, change the PWM duty cycle to achieve dimming. Compared to cut-phase dimming, the advantages are good compatibility with lamps and lanterns, dimming curve smooth, no noise, no flicker, etc.; but the wiring is slightly more complex, in the circuit according to the strong power wiring at the same time, but also need to lay additional signal lines. Compared to DALI dimming, 0/1-10V dimming can not achieve single light control, the later can not be adjusted to the lighting circuit, while 0/1-10V voltage in the signal line length changes on the corresponding attenuation is also a problem to be considered in the pre-planning line. Compared to DALI dimming, 0/1-10V dimming can not achieve single light control, the later can not be adjusted to the lighting circuit, while 0/1-10V voltage in the signal line length changes on the corresponding attenuation is also a problem to be considered in the pre-planning line.
DALI dimming, which is also essentially PWM dimming, can be understood as a digital upgrade of 0/1-10V dimming. The signal line within the transmission is no longer a specific voltage, but a digital signal, through digital addressing, within the rules of the DALI protocol, you can freely plan the lighting circuit without wiring restrictions, with the possibility of more combinations of lighting scenes. And compared to 0/1-10V dimming, DALI signal line is non-polarity, completely afraid of interference, you can walk with strong wires in the same tube, the second difference is that the traditional lighting circuit concept is missing.
There is no best dimming technology, only the most suitable for each home lighting design situation configuration program.
