How a dimmer works

Dimmer, an electrical device that changes the luminous flux of a light source in a lighting device and adjusts the illuminance level. The purpose of a Dimmer is to adjust the brightness of different lights. By reducing or increasing the RMS voltage to cause the average power of the light to produce different intensity of light output. Although variable-voltage devices can be used for a variety of purposes, this regulation is intended to control lighting.

There are three principles of Led Dimmers
1. Pulse Width Modulation (PWM) digital power square wave, and control the duty ratio of square wave, so as to achieve the purpose of controlling the current.

2 constant current power supply control with analog linear technology can easily adjust the size of the current.

3. Grouping and control Grouping of multiple LEDs, with a simple grouping and control, Dimmer Switch

The above 1.2. Two methods can use adjustable resistance knob for segmentless control. Due to the technical maturity of PWM module, the cost is reduced. It is difficult to determine which type of flow control is used in terms of price. Yet adjustable resistors by themselves are not a very reliable device. Often because the dust into or manufacturing process is not tight, in the operation of adjustable resistance there will be an instant jump fault, then the light source will flash. This flashing is not obvious in the case of PWM mode, but more obvious in the case of linear technology to control the current.
No matter how the current is controlled, it can be changed to a Tact Switch or a separate block Switch (such as a pacer, remote control, Dimmer Switch) to control the light. This kind of quality is more reliable, the service life is much longer. It is necessary to use adjustable resistors for delicate lighting control. It is recommended to use high-quality adjustable resistors.

Whether the LED Dimmer is driven by step-down, step-up, step-down/step-up, or linear regulators, the most common thread connecting each drive circuit is the one that needs to control the light output. There are only a few applications today that only require simple on and off functions, and most require fine-tuning from 0 to 100%. For luminosity control, the two main solutions are to adjust the current of the LED linearly (analog dimming) or to switch the driving current back and forth from 0 to the target current value (digital dimming) at high frequencies that are imperceptible to the naked eye. Using pulse-width modulation (PWM) to set the cycle and operating period is probably the easiest way to implement digital dimming because the same technique can be used to control most switching converters.