I appologize in advance if this have been answered before, but I really googled a lot before asking.
In general, I have a 9v battery and I want to get 9v output from the 13th pin of Arduino. For that purpose I was advised to buy a resistor, an IRF530 transistor and a small red breadbord (the one without letters and other martks). I am looking for a scheme for how to connect everything.
Thanks in advance.
Resistor (hopefully somewhere between 1k and 100k resistance) between Gate and Source of the MOSFET.
Source is connected to ground of Arduino and - side of battery.
Positive side of battery is connected to positive side of load, negative side of load connected to Drain of the MOSFET.
Gate is connected to digital pin of Arduino. It is recommended to put a 100 ohm resistor in series here, though you can get away with not doing so.
There are lots of guides with more detail on how to connect MOSFETs (like the IRF530) or BJT's (like the TIP series), and go into great detail. I suggest you read some of them. Literally thousands of guides and writeups on this can be found online with minimal effort.
Note that the IRF530 is not meant to work with a 5v signal on the gate, and is suitable only for light loads with 5v gate drive. You should use a "logic level" MOSFET instead of the IRF530. Of course, with one of those common rectangular 9v batteries with the snaps on top, a light load is the only kind of load you can power with them - those things can't supply much of any current.
Sounds like bad advice all round, that's not a logic level MOSFET and a simple 2N2222 + resistor
would likely have been fine and cheaper - if the load is powered from 9V battery its going to be low
current, because those batteries can only handle light currents (up to 50mA or so without overloading)
pastet89:
I appologize in advance if this have been answered before, but I really googled a lot before asking.
In general, I have a 9v battery and I want to get 9v output from the 13th pin of Arduino. For that purpose I was advised to buy a resistor, an IRF530 transistor and a small red breadbord (the one without letters and other martks). I am looking for a scheme for how to connect everything.
Thanks in advance.
Important details are missing, so we must guess.
A 9volt battery can't supply a lot of current, so a 100volt/14Amp mosfet is just silly.
And this mosfet is not suitable for Arduino anyway.
A 2N7000 would be better here if you want to go "mosfet".
But in this case, a small transistor would do equally well.
Question is what do you want to connect/switch.
Leo..
This is referred to as the "XY problem".
We need to know why you need "to get 9v output from the 13th pin of Arduino" before we can advise how to do that in a manner suitable for your purpose, if it is indeed necessary at all.
And as part of that, we also need to know what you mean by a 9 V battery.
9 times out of 10 on first posts here, "9 volt battery" means a 006P "transistor radio" battery.
evildave_666:
9 times out of 10 on first posts here, "9 volt battery" means a 006P "transistor radio" battery.
Ergo my pointed question. 
Since no one else is going to ask, I guess I'll have to:
WHAT IS THE LOAD THAT REQUIRES 9V ?
raschemmel:
Since no one else is going to ask, I guess I'll have to:
Reply #4 perchance?
Reply #4 perchance?
Close, but no cigar. You didn't ask what the load is.
And as part of that, we also need to know what you mean by a 9 V battery.
I think we know he means a PP3 smoke alarm battery.
raschemmel:
Close, but no cigar. You didn't ask what the load is.
I believe I did one better.
I agree the " 13th pin" thing is a bit weird.
No mystery on the "9V battery" part though.
I just wish we didn't always have to play 20 questions.