Electrical Signal Routing with N and P Channel MOSFETs

In this video we look at how to route DC signals using N and P Channel MOSFETs as switches. This will be part 1 in a four part solid state switching series. In part 2 we will look at switching AC Signals with a TRIAC.
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[@NotMarkKnopfler]

I don't know why engineers fail to point this out, so I'll do it to make it easier for those that are interested. Why are they called "N" and "P" channel? Well an N channel MOSFET goes on the NEGATIVE side of the load (closest to ground), while a P channel MOSFET goes on the POSITIVE side of the load. It's as a simple as that. Yet you won't find ANYONE actually pointing it out in KZbin videos. Baffling. Great video though - really excellent. 👍 Subbed.

[@ForceTronics]

Glad you enjoyed the video! Your 'N' and 'P' naming story is a good rule of thumb for how to implement MOSFETs, but I don't think it is correct on the real genesis of the name. My understanding is 'N Channel ' comes from the fact that negative doping semiconductor material is the majority material compared to positive doping. The negative doping material connects to the source and drain. The positive material connects to the gate. P channel MOSFETs are doped opposite. That is my understanding at least of the naming

[@rraheem_p]

How timely 👏🏾👏🏾

[@DaVeHiLl200]

Great video mate thank you. One thing I failed to grasp is how to work out +RP and RCL+ resistor values needed for N Channel?🤯 I've designed a small circuit with 2x IRFP260N mosfet in parallel, I'll be operating the gate with arbitrary frequency generator to allow complete control of pulse frequency to experiment with electrolysis liberating gasses from water. Are there formulas for both resistor applications? I'm no electronic engineer but keen to learn what I need to know. Cheers mate 👍

[@ForceTronics]

Good question. Rp is fairly trivial and may not be needed. It's more of a safety thing because modern MOSFETs require so little current to turn on. Just use a resistor value of 10k and you'll be fine. RCL is a gate current limiting resistor and also may not be needed. It is there to ensure the gate capacitance doesn't cause inrush current that could damage the source. If you are not highly concerned with switching the MOSFET on and off at it's fastest rate then just use a resistor value around 300 to 1k ohms and you should be fine

[@Enigma758]

11:28 I think there are situations where RDIV can be eliminated (replaced with a wire) as long as you are within Vgs(max). Would you agree?

[@ForceTronics]

Yes, great comment 👍