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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.

Seph Reed
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  • Just as a note of interest. Apparently MOSFETS are very popular in the vaping community. It's come up a lot in my searching. – Seph Reed Jan 27 '17 at 03:07
  • 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. – Jack Creasey Jan 27 '17 at 03:13
  • 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. – Seph Reed Jan 27 '17 at 03:15
  • 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. – Seph Reed Jan 27 '17 at 03:30
  • The search you're looking for is N channel switch. What the heck is a basic MOSFET anyway? Are there advanced MOSFETs for the professionals? – Matt Young Jan 27 '17 at 03:34
  • I meant to say basic MOSFET wiring. I'm very new to this, so I'm still trying to get a foot hold on the simple cases. I imagine there are some "hello world" level cases for using MOSFETS which my work as a good introduction to them. I was looking for one of those. Something you might be likely to see on the back of a package, that gets the basics across through example. – Seph Reed Jan 27 '17 at 03:36
  • N channel switch led to this http://electronics.stackexchange.com/questions/67343/mosfet-as-a-switch, which is very helpful. Thank you. – Seph Reed Jan 27 '17 at 03:43
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    You have to specify the load, exactly what it is or this question will be to broad. – Voltage Spike Jan 27 '17 at 03:45
  • I don't think the load is necessary for grasping the basics of what each of the prongs on a MOSFET are for, or how they generally relate to a power source. This is a very nooby question, which probably has both a very complex and in depth answer and also a very nooby answer. Either will help me at this point. – Seph Reed Jan 27 '17 at 03:49
  • I found my problem. Someone handed me a transistor and called it a MOSFET. I looked up MOSFET and saw pictures of thing I was holding. – Seph Reed Jan 27 '17 at 04:06
  • @SephReed No no no. First, Mosfets are a type of transistor. Field Effect Transistors. "Transistors" also apply to Bi-Polar Junction Transistors, like NPN and PNP transistors. But do NOT think that they look different. Mosfets and Transistors both use the same packages, like TO-92 or TO-220, as do other parts. You will find Linear Voltage Regulators in the same packages. The only thing that will tell them apart is the PART NUMBER ON THE DEVICE. – Passerby Jan 27 '17 at 06:12

1 Answers1

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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.

schematic

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.

Passerby
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