I have searched "how to wire a MOSFET" in a few different wordings and looked at a bunch of MOSFET wiring diagrams, but I can only seem to find the more complex examples of a MOSFET wiring.

Currently I have a low voltage switch (coming from a RaspberryPi) I want to use to turn on and off some 5v lighting.

The four wires I have are the positive and negative for my switch (low voltage), and the positive and negative for the light (5V).

I'm not sure if my scenario is the right one for whatever the most basic form of MOSFET wiring is, but I'd like to start by understanding this.

What is the basic way of wiring a MOSFET? Could someone please show me a diagram?

EDIT: so far, this instructable is the best novice description I have found.

EDIT 2: This question pertains to a basic example of MOSFET wiring. My scenario happens to exist in a different question, but the answer I'm looking for is not simply how to solve my particular problem, but (in the most basic case) how to wire a MOSFET.

P.S. I know this is probably an incredibly basic question to anyone who knows the answer, but as stated above, I'm only finding answers to complex questions about MOSFETS on the internet, and the part I bought did not come with what is most likely a very simple diagram.

  • \$\begingroup\$ Just as a note of interest. Apparently MOSFETS are very popular in the vaping community. It's come up a lot in my searching. \$\endgroup\$
    – Seph Reed
    Jan 27 '17 at 3:07
  • \$\begingroup\$ Start by explaining what part you have and the LED you want to drive. If you have searched and found a schematic you think you should be following, include that too. \$\endgroup\$ Jan 27 '17 at 3:13
  • \$\begingroup\$ While I am hoping this question pertains to my particular problem , any schematic which shows the way MOSFETs are usually used would be helpful in beginning to understand them for me, and could then lead to a more specific question about my particular wiring scenario. \$\endgroup\$
    – Seph Reed
    Jan 27 '17 at 3:15
  • \$\begingroup\$ Thank you. The linked question looks very helpful for my project, but it doesn't seem to describe how to wire a basic MOSFET. I'd like to understand this before following the linked schematic. \$\endgroup\$
    – Seph Reed
    Jan 27 '17 at 3:30
  • 1
    \$\begingroup\$ You have to specify the load, exactly what it is or this question will be to broad. \$\endgroup\$
    – Voltage Spike
    Jan 27 '17 at 3:45

The problem with your question is that there is no single way to wire them. There are two major types of Mosfets, and multiple topologies (ways to wire them), with each having a different usage.

Ignoring most of them, the simplest is a Mosfet as a switch.


simulate this circuit – Schematic created using CircuitLab

A N-Channel as a Low Side, Active High switch, or a P-Channel as a High Side, Active Low switch. This works to turn on/off the Load based on the Gate voltage.

Note: Since your RPi has a 3.3V output, you will need a 3.3V Logic Level mosfet, or will need to use a mosfet driver circuit, making it even more complicated.


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