Looking at how a MOSFET is used as a variable resistor that can be controlled by the gate voltage. In this video the MOSFET is incorporated as part of a simple potential divider.
Great circuit. You may want to put a fixed resistor in series with the pot to avoid a battery short at extreme end. I’m sure you know. May not be clear to all the readers.
Very interesting and nicely explained, thank you! Q: when using an N JFET (e.g. 2N5457), all works the same? The resistance/control voltage curve would be less steep for example? = the ohmic region being wider or something. Many thanks in advance!
Pretty good men, btw for all the ones that want to know what's the resistor value(R_DS), you just need to solve for R2 in the voltage divider equation, e.g.: @6:03, Vout = 0.48V, so solving for R2 in the voltage divider then we have a resistor of 923.07Ω, [eqn.: ((R2*1V)/(1KΩ + R2)) = 0.48V] .
So how can someone use a mosfet as a variable resistor when its resistance characteristics are absolutely non linear? After a certain Vgs, the resistance drops so rapidly to almost zero 👎🏾
Simple, it's perfect. Thanks.
Great circuit. You may want to put a fixed resistor in series with the pot to avoid a battery short at extreme end. I’m sure you know. May not be clear to all the readers.
Very interesting and nicely explained, thank you! Q: when using an N JFET (e.g. 2N5457), all works the same? The resistance/control voltage curve would be less steep for example? = the ohmic region being wider or something. Many thanks in advance!
Pretty good men, btw for all the ones that want to know what's the resistor value(R_DS), you just need to solve for R2 in the voltage divider equation, e.g.: @6:03, Vout = 0.48V, so solving for R2 in the voltage divider then we have a resistor of 923.07Ω, [eqn.: ((R2*1V)/(1KΩ + R2)) = 0.48V] .
Needed this video so much
Merci! Very interesting.
What type of MOSFET are you using?
what is the 5 pin mosfet looking thing in my cheap ebay 24 vdc to 12 vdc converter? it went poof in a puff of smoke.
very nice experiment
Thank you for your comment and sorry it took so long to reply
Also, which MOSFET it's used for the video?
Excellent
Thanks
👍❤️
Thanks for all the positive comments, glad you find it all useful
why series resistor used in gate terminal ....???? and how to calculate thats resistor value when i used as swiching purpose
So how can someone use a mosfet as a variable resistor when its resistance characteristics are absolutely non linear? After a certain Vgs, the resistance drops so rapidly to almost zero 👎🏾