Whether LED by buck, boost, buck/boost or linear regulator driven, connect each drive circuit is the most common thread need to control the light output. There are only a handful of applications that need to be opened and closed, most of which need to be tweaked from 0 to 100%. Two aspects to control the luminosity, the main solution for linear control the LED current (analog dimming) or imperceptible to the naked eye under high frequency, let drive current to the target current value from 0 to switch back and forth between (digital dimming). Using pulse width modulation (PWM) to set the cycle and the cycle time is probably the most simple to realize digital dimming method, the reason is that the same technology can be used to control most of the switching converter.
Packet control will be grouped by multiple leds, with simple packet-control. The two methods can be controlled with adjustable resistance knobs. Due to the technical maturity of PWM modules, the cost is reduced. It is difficult to determine the flow of controls in terms of price. But the adjustable resistor itself is not a reliable component. Often because the dust enters or the manufacturing process is not tight, when operating adjustable resistance, there will be a sudden and empty failure, the light source will flash. This is less obvious in PWM than in the case of linear technology. , no matter how to control current can be changed to touch type button Switch, Tact Switch) or a separate packet Switch (e.g., grouping, remote controller) to control the lights. The quality is reliable and the service life is much longer. It is necessary to use adjustable resistance to adjust the light of the light, and it is recommended to use high quality adjustable resistance (usually a few yuan to 10 yuan).
Constant current power control is used to simulate linear technology to easily adjust the size of current.
There are three kinds of LED dimmers The Pulse Width Modulation (PWM) is digitizing the power source and controlling the air ratio of the square wave, thus achieving the control of the current.