hi friends! I have a arduino mega with a 5v index led strip.

hi friends! I have a arduino mega with a 5v index led strip. its work fine but i like dimming the strip.
I use a mosfet irfz44n but it dont work. i only get 3 volts. I can work with this mosfet.

I’m not entirely sure what the irfz44n does, but I can’t see why you would want that in your circuit with the LED strips. If you want to dim, dim them in software. if you want to dim all LEDs, use set_max_brightness(0-255), otherwise just set your pixel values accordingly. The LED strips dont respond great to being under or over-volted, so you should stick as close to their nominal value as possible.

Here is the schematic I used when using analog LED strips. Try the ones listed in here: https://dl.dropboxusercontent.com/u/10830255/Arduino%20RGB%20on-beat%20leds%20Project/Scematics%20on-beat%20RGB%20strip.pdf

What kind of LED strip are you using? Addressable or non-addressable?

@Buddy_Smith Because he said he was using a transistor, you have to assume he is talking about the analog versions.

It wouldn’t surprise me if someone was trying to dim an addressable strip with a MOSFET…I never assume what others have done, especially if things aren’t working.

You don’t want to drop the voltage that you’re feeding into addressable strips, it will mess with the controller chips on the strip and give you all sorts of fun glitching. Use LEDS.setBrightness(…) to globally drop the brightness of your leds.

Its a addressable strip. I assume for yours posts that a addresable stip cant use a mosfet

Correct. Connect the power directly to the strip. Do not run it from your Arduino’s power supply unless you’re absolutely sure it will not draw more power than the Arduino can supply. To control the brightness, use the functions in FastLED as others have said.

Ok thanks i didnt know that a function existed for dimming the strip. The strip works direct to the power. I have 8 m addresable strip.

Thanks to all.