Toggle switch with MOSFETs

[Mathieu]

Hello,

I would like to switch between 2 power sources for 1 load from a microcontroller, and I guess it's possible to do it with power MOSFETs?

With a good choice of MOSFETs, the power lost from the batteries could be very low? I would need 2 MOSFETs?

If you have any suggestions, don't hesitate. The load will draw a minimum of ~0.5A at 18v but a maximum (very rarely) of up to ~22A (it's fine with the batteries used).

I really don't know if it's a good solution or not...

Thanks!!

 

[Externet]

Is it 4 options like source1, source2, both, and none? Or just two: source1, or source2 ? It would be convenient to simplify with two mosfets. Battery energy does not need to be lost. Performs an action of running the load.

 

[Mathieu]

Is it 4 options like source1, source2, both, and none? Or just two: source1, or source2 ? It would be convenient to simplify with two mosfets. Battery energy does not need to be lost. Performs an action of running the load.

Thank you, it's source1 or source 2 when possible. Only none if the batteries are emptied and the power supply is not connected.

 

[Mathieu]

I'm pretty sure this is not the right way to do it with N-Channel MOSFETs?

 

[Mathieu]

I just saw I should use a Power Multiplexer (Power MUX) in this case?!

https://www.ti.com/lit/an/slvae51a/slvae51a.pdf

 

[Bluejets]

Look for switching using "high side " P type mosfets.
You will require logic level mosfets as well.

One place of many to start..... https://www.digikey.com/en/maker/blogs/introduction-to-high-side-load-switches

 

[Mathieu]

Look for switching using "high side " P type mosfets.
You will require logic level mosfets as well.

One place of many to start..... https://www.digikey.com/en/maker/blogs/introduction-to-high-side-load-switches

Thank you, this source will be better than many YouTube videos!

Another source I like : https://www.vishay.com/docs/70611/70611.pdf (source of the 2 images below)

If I remember well, it's their documentation that helped me the most to create SSR (for better smart plugs without relays). I bought a nice book about electronics, I should read it one day...

@Bluejets is it exactly what you wrote?!

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[Mathieu]

My goal is to (ideally) use 0% of the batteries when there's no load and no power supply connected. I don't even want to see the lights of the power supply and the charging module turning on when the batteries are charged and the power supply disconnected. The load can take different voltages.

Maybe I should use one or more diodes and it would still be very close to 0%? I clearly don't understand enough so this thing will also help me to learn more!

 

[Mathieu]

If you want to draw anything on it...