The principle of LED dimmer has three kinds
The 1. wave width controlled Pulse Width Modulation (PWM) digitized the power square wave and controlled the duty ratio of the square wave, so as to achieve the purpose of controlling the current.
2. constant current power regulation and control using analog linear technology can easily adjust the current size.
3. grouping control will divide multiple LED packets into simple groups.
The above two methods of 1.2. can be controlled by a variable resistance knob. Due to the maturity of PWM module technology, the cost is reduced. It is difficult to determine which way to control the flow from the price side. However, the adjustable resistor itself is not a very reliable component. Often due to the dust entering or the manufacturing process is not tight, there will be a momentary jump in the operation of adjustable resistance, so the light source will flicker. This kind of flicker is not obvious in the way of PWM, and it is obvious that the current is regulated by linear technology.