A few weeks ago, I asked about controlling a DC powered LED lamp using PWM here, I was told that if I can get a LED lamp that uses an external DC adapter to power up, I can use a MOSFET and control it using PWM.

So I have found a LED lamp from Ikea, it's the HARTE LED Lamp, it is powered off a USB cable. As far as my understanding go, USB provides a DC power, so I am understanding that I should be able to control it, dim it by modifying the USB cable, attach a MOSFET to it, is that right?


1 Answer 1


If it uses a USB cable, that should be 5 VDC, so yes, but there's a caveat.

There might be some active circuitry in the lamp already, controlling the LED. If that is the case, adding PWM to the input power may or may not give you the result that you want.

  • \$\begingroup\$ If there is no active circuitry in the lamp, would I be able to control it properly then? \$\endgroup\$
    – lwschan
    May 13, 2016 at 14:59
  • \$\begingroup\$ I can't see why not. \$\endgroup\$
    – Dampmaskin
    May 13, 2016 at 15:02

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