I'm trying to make an LED strip that I bought off Amazon work with my Raspberry Pi. It works just fine when I connect it through the included adapter which I took apart (shown below):

Here's the adapter the LED comes with

However, it is a bit cumbersome, so I am trying to connect it through my raspberry Pi instead. From what I could gather, the two big chips are the ones that control the input from the user to control patterns, PWM, varying brightnesses, etc. Since my thing just needs to shine one of three colors, I think I don;'t need them. From what I researched, the three little microchips next to the RGB wires are MOSFETs. I googled tham and found some that could fit on my breadboard, and made sure they were the same logic voltage, the same junction type, etc, etc.

However, when I actually try to actuate everything, including the 12V power supply fed directly into the common line combined with the MOSFET regulated pulse, something weird happens. The lights light up, but with nowehere near the intensity as they do with the PCB it came with. I'm wondering, is tehre something I'm missing? Are the MOSFETs the wrong type?

Here are some images that might help: PCB the LED strip came with

Mosfets (P30N06LE)

More pictures of the MOSFETs

  • 1
    \$\begingroup\$ your wiring is unclear. dim but working sounds like the mosfets are under-voltage on the gate; what's the model? do you need p-chan mosfets if the colors share a common ground? \$\endgroup\$ – dandavis Sep 26 '17 at 1:25
  • 2
    \$\begingroup\$ Your RPI 3.3V output is not high enough to trigger that is likely a 5V board and mosfets expecting higher than 3.3V. Or there is something else. We need a schematic. \$\endgroup\$ – Passerby Sep 26 '17 at 1:27
  • \$\begingroup\$ you need <=1V Vgs(th) MOSFETs \$\endgroup\$ – Tony Stewart EE75 Sep 26 '17 at 1:28
  • 4
    \$\begingroup\$ "I googled tham and found some that could fit on my breadboard" And what are they, exactly? What part number? \$\endgroup\$ – WhatRoughBeast Sep 26 '17 at 2:54
  • \$\begingroup\$ ... and your schematic is where? From the photos of your rat's nest is seems as though you haven't got all of the pins of your MOSFETs connected. Is this true? \$\endgroup\$ – brhans Sep 26 '17 at 11:46

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Browse other questions tagged or ask your own question.