Thank you AnalogKid for the explanation. I started some weeks ago thinking there was more to it than NO/NC but I couldnt really point out how it worked. Also because I know theres a lot basic knowledge about electronics I am missing.

For example in the curcuit in #12 where the 4k7 resistor does something important to how the current flows I think, but I cant figure out what. And also why it says "Motor_DC Batt+" in the diagram. The motor is already electrified elsewhere.

I will keep "reading".

 

hi C,
Basically, the first MOSFET you used required at least 4Vgs between Gate and Source to start it lightly conducting, so to be sure of being fully On it would require Vgs of 10v.
[which you do not have available]
The second MOSFET which bertus posted only require s 2Vgs to start to turn it On, so a voltage of 4.5Vgs would be more than enough to turn on the MOSFET for good conduction.
E

 

hi C,
Basically, the first MOSFET you used required at least 4Vgs between Gate and Source to start it lightly conducting, so to be sure of being fully On it would require Vgs of 10v.
[which you do not have available]
The second MOSFET which bertus posted only require s 2Vgs to start to turn it On, so a voltage of 4.5Vgs would be more than enough to turn on the MOSFET for good conduction.
E

I thought the transistor was either on (conduction) or not. Didnt think it was "dimmable" (in lack of other terms). If I may say so, "Mr. Mosfet" and "Mr. transistor" should have invented them to turn fully on at any voltage and current. Even the tiniest should turn it fully on.

So it it possible to read in a datasheet which voltage that turns the transistor fully on?

 

hi,
No,,, a transistor is a 'trans -resistor' which means its Collector to Emitter current conduction can be controlled over a wide range, of course if you apply a high enough voltage between the Base and Emitter it will be fully ON , known as saturation.
The controlled conduction range is called the Active region.

E

 

oh thats what "saturation" means, thanks.