LED drive power selection
The dimming performance of LED lighting fixtures depends on the LED light source and the driving power source.
In general, LED light sources can be easily divided into two broad categories: individual LED diode sources or LED diode sources with resistors. In applications, sometimes LED sources are designed as a module with a DC-DC converter. If the LED light source or module is a separate LED diode itself, the common dimming method is to adjust the amplitude of the LED input current, so the selection of the LED driving power supply should refer to this feature. Another type of LED diode light source (generally called LED strip or LED STRIP) with a resistor, LED strip is widely used as a resistor with LED diodes in series, so the voltage is relatively stable, so users can access it. Any fixed voltage power supply is commercially available to drive the LED strips.
Common LED strips are typically driven at 12 VDC or 24 VDC, but may therefore be somewhat difficult in dimming applications for LED strips. This article describes the application of the current amplitude dimming driver to the LED strip, and also discusses some common dimming issues, and introduces the dimmable LED power driver with output pulse width (PWM) modulation.
Dead travel is a frequent problem when using LED power drivers with adjustable output current for LED dimming. Although the LED driver can be operated very well when it is fully loaded (as in Figure 1-a), when the LED driver is not fully loaded, the dimming is not smooth.
If the LED light strip dimming application is used with LED drive power under full load conditions, then there is no problem with dead travel. The above arguments are correct, but they are not very practical. In fact, LED strips are often used in a variety of applications (decorative lighting / auxiliary lighting / advertising lighting) because the length can not be accurately estimated, so the simplest and best The application solution should correctly select the LED driver power supply with the output pulse width PWM dimming function to realize the LED light bar dimming requirements.