Controlling two micro fans (5V 0.06A) with a N-Channel Mosfet

I’m want to control two micro fans (both 5V and draw 0.06A each) using an Arduino Nano. I plan to use a single N-Channel Mosfet (FQP30N06) with two diodes (1N4004). I’ve attached a schematic of my circuit. I want to to double check it’s all good before I send off my Gerber files to get pcbs milled.

FQP30N06 Datasheet:

Why do you short the gate of the FET to ground ?


Use circuit C1.

In addition to already mentioned mosfet error, you’ve only shown the the top left part of the schematic. So, consider posting the entire schematic if you want a proper review. Even better, post both schematics and gerbers (as jpg) if you want the board layout reviewed as well. Newbies tend to use inappropriate trace widths and omit ground pours.

Thanks for the feedback. I’ve attached an updated FULL version of my schematic and jpg of gerber file. I think I accidentally shorted the gate pin to GND originally, because I miss-wired the 10K pull down resistor for the gate.

I didn’t post the entire schematic b/c I wanted to draw focus to the mosfet wiring I was unsure of.

In addition to using a n-channel mosfet to control two fans, this board has 5 tactile buttons, a mic input and stereo line input, and a header for I2C and SPI communication to another board.

PCB looks fine, but don't be scared to use wider tracks if you can where power is concerned.
For example around the MOSFET and associated fans.

It is good you have kept the fan and MOSFET close to the power input pins.

It may be worth putting some bypass capacitors at the power input and the power pins of the Nano socket.

Thanks.. Tom... :slight_smile:

R2/3/4/5/11 make no sense, that’s not a proper digital method.

Replace them with zero ohm jumpers and use the INPUT_PULLUP feature to provide current to the input. The logic will be inverted, input is LOW when a button is pressed.

You only need a single diode as the two loads are in parallel.