Hello Arduino Community and thanks for taking the time!
My Problem is, that Im planning to use a IRFZ44N Mosfet to control when a motor shoult spin and when not. In Theory the curcuit is working but the mosfet behaves weired (to my limited knowledge). When Im wiring it exactly like in this image Adam meyer | Arduino + N-Channel_MOSFET it does work but the motor runs way slower than he could and the mosfet warms up quite quick. 11V to the gate instead of the arduinos' five dont make any difference. However if I now just connect a cable to the gate pin and touch it with my bare finger the motor turns with full speed and the mosfet is chill but it wont stop when I pull my finger away since there is no pulldown resistor anymore. Re connecting the resistor makes it stop, re connecting the Output Pin makes it turn slower. Any help on how I can let the Motor spin fullspeed without my finger on the mosfet would be highly appreciated!
Double check that. For sure, you are using the wrong MOSFET because Vgs is 4V on that part, too high. "In theory" it is not working, because the MOSFET is not saturated (fully on) at 5V.
Double check your wiring, because it may match the diagram only in your mind.
Don't rely on random blogs that publish specious guesses like, "you can use any N-Channel MOSFET exactly the same way".
I wouldnt have come here if I hadnt doublechecked everything with several different wires, mosfets, diodes and even arduinos but sure keep on ranting without proof. I also not just checked one image on one internet page and immediately gave up, I`m trying since at least three days to get it working with hints I picked up in various other threads where people in need came to get bullied 90% of the time by the ones who know instead of getting help.
Literally the only thing to do in Forums is help others, yet most of the time it`s more toxic than Twitter
For sure, with that attitude you will never get any help from anybody here. The bullying and toxicity is only in your imagination. Please feel free to index a few of my other threads to see that I am here to help people out.
Definitely, it is not a rant to point out an extremely common mistake, using a MOSFET with an insufficiently high gate threshold voltage. That is just a simple fact. It also matches your problem report perfectly. So it would behoove you to apologize for your exaggerated response, or else other people may read this and be unwilling to help you.
I did take the time to look up the data sheet of the MOSFET. All the proof you or anyone needs is there.
Can you please post image(s) of your project so we can see your component layout?
Can you please post your code in code tags?
Does your motor run faster connected directly across the battery?
What value is the pulldown gate resistor?
When connecting the gate to an 11V supply, is the ground of that supply connected to the Arduino ground (which is also the Source terminal of the mosfet)? If it is, then the mosfet should turn fully on with 11V on the gate. If it only turns on partially, or not at all, then something else must be wrong. I was thinking the Drain and Source might be wired backward, but I don't think it would turn on at all if that were true.
Except for it not working with 11V on the gate, aarg's explanation would appear to be correct. The threshold voltage of your mosfet is twice that of the example circuit mosfet, and it just may not be turned on enough with 5V on the gate. Do you actually measure 5V on the Gate with your meter?
