LED DIMMER FLICKER SOFTWARE

Unfortunately, many PWM dimmers use a frequency that is too low. Virtually all LED strip dimmers and 'color changing' controllers (CCT or RGB) that are installed on the low voltage DC side of the circuit utilize PWM to achieve their desired effects.

PWM induced flicker is caused by PWM LED dimmers and controllers. At high enough frequencies, PWM can safely be used for virtually all applications, including high speed cameras. PWM is the most efficient and practical way to achieve the illusion of dimming, and the faster the PWM frequency, the less perceivable the flicker. In reality, however, the LEDs are either at 0% or 100% brightness - and to achieve the illusion of 50% brightness, the LEDs are at 0% brightness (off) half the time, and 100% brightness (on) the other half. By varying the relative time between its on and off states, PWM can be used to create the perception of different brightness. PWM is an intentional manipulation of a DC power source, between on and off states.

The second source of flicker in an LED is pulse-width modulation, or PWM for short. If you own any LED bulbs that screw in to a standard E26/E27 Edison base, or otherwise connect directly to mains electricity, the primary source of flicker is in the bulb itself, and will require replacement of the entire bulb. As such, the extent and severity of flicker caused by the AC signal is determined by the LED bulb electronics, which almost always is embedded in the bulb itself. Even a simple rectified AC signal will cause an LED to flicker at 100-120 times per second.ДЄn LED bulb with more sophisticated electronics to convert the AC signal into a smoother, DC signal will produce less flicker. The result is that an LED bulb may flicker between its on and off states at 100-120 times per second.ДЇigure 1: A graph showing the alternating current waveform, which repeats 50-60 times per second.

With a simple rectified AC input, an LED system can function, but will momentarily cease or significantly decrease its light emission at each of the 'valleys' that occurs 2x per cycle. As a result, electronics components are needed to 'rectify' and smooth out the fluctuating AC signal. As LED devices are inherently designed for DC (direct current) input, the AC waveform is inherently incompatible. A 120 V AC input voltage actually is a reference to its average (RMS) voltage level - in reality, it can fluctuate anywhere between -170V and 170V. Alternating current, as its name suggests, alternates between positive and negative voltage/current in a sinusoidal waveform, 50-60 times per second. The first is caused by the fluctuation inherent in AC power. There are two sources of flicker in an LED - AC power or PWM - and it is important to determine the source of the flicker so that it can be directly tackled. While this new development is helpful for taking photographs, this makes it less effective in diagnosing flicker.

LED DIMMER FLICKER SOFTWARE

Note: recent developments in smartphone software have helped eliminate the dark lines that used to frequently show up in still photos. See here for a video demonstrating the use of this method at a retail store. If there is no flicker present, the light source should appear stable and continuously emit the same levels of light throughout the slow motion video. If there is significant flicker in the light source, you will see it appear as a conspicuous flicker or repeated flashing on the slow motion video. Now, carefully watch the video you just recorded. Stop the recording after 2-3 seconds, and you're done! Then, point the camera at the light source in question, and hit record. Simply load the camera app, and swipe to the right twice to toggle the 'SLO-MO' video setting. Instead, we recommend a quick and effective way to determine flicker using just a standard iPhone and its built-in camera app. At purchase prices starting at several hundred dollars per test unit, this is obviously not practical for most consumers concerned about flicker in their light bulbs. The most scientifically accurate way to determine the extent and severity of flicker is to use specialized equipment such as an oscilloscope or light meter. Although intended to flicker at a rate that is fast enough to go unnoticed, for some sensitive individuals and applications, the severity of flicker in some LED systems can be excessive and problematic.

At its core, LED flicker is caused by a rapid on-and-off flashing of the LED.

Led dimmer flicker