MOSFET triggered by transistor

Dear users,

I got a question regarding using MOSFETS.
For my project an Arduino will be placed on my moped and will trigger things like a 12V horn or blinkers which will be either blinking or possibly fading.
My idea was to use an N-channel logic MOSFET, which can be switched by the Arduino.
I saw some people using the Arduino to switch a transistor which will then trigger an N-channel MOSFET.
Like here:

Or here:

Do you know if this is necessary or if I can use only an N-channel logic MOSFET?

Sincerely, Jelle

You can just use an N Logic MOSFET. Search Google for more information regarding this

JelleBezemer:
My idea was to use an N-channel logic MOSFET, which can be switched by the Arduino.

A MOSFET like this: N-Channel MOSFET FQP30N06L
will work fine when controlled directly from a 5V Arduino.

Other mosfets might not. You would have to check the datasheet.

Note that the circuit diagram on one of those links you gave looked like it was using P-Channel MOSFETS, if you need a high-side switch like this, then you do need the transistors to switch the MOSFETs.

Yours,
TonyWilk

Usually automotive systems use high-side switching as the ground return is direct to the chassis, so its not
possible to switch on the low-side... So NPN driving p-channel FETs is probably needed.