Most LED bulbs on the market actually have a dimmer switch if you are using a CFL / LED dimmer. And let’s figure out what the differences are in these lamps.
Standard 3-way bulbs have two separate circuits with separate filaments and contain a miniature step-down converter of mains voltage, the so-called pulsed DC-DC converter. One filament is the “low” one, the other is the “medium” one, and they both get turned on in the “high” setting.
The task of this unit is to receive an alternating mains voltage (220-230 volts), first rectify it into a constant voltage. Then convert this constant voltage into a low constant voltage at the output of the lamp, and the value of the resulting output voltage must exactly correspond to the set load, that is, a chain of LEDs, which is in this particular lamp.
A dimmable LED lamp (dimmable lamp) differs from a non-dimmable one in that there is an additional circuit at the input of its built-in DC-DC converter that measures the RMS value of the applied AC voltage. Moreover, the LEDs at the output voltage are set corresponding – proportional to the input. If the voltage from the dimmer is insufficient, the lamp circuit will see this and behave adequately – it will reduce the brightness.
However, the limits of regulation and the accuracy of tuning the internal lamp driver depend on its quality. Therefore, when choosing a dimmable LED lamp, preference should be given to lamps from reliable manufacturers.
And of course, it is important to remember that a dimmable LED lamp necessarily has a “dimmable” mark on the packaging.