Jfet buffer

Discussion in 'General Electronics Chat' started by coinmaster, Mar 1, 2016.

  1. coinmaster

    Thread Starter Member

    Dec 24, 2015
    350
    6
    What happens if I do this?

    Screenshot_6.png

    Would this create a DC voltage buffer?
     
  2. AnalogKid

    Distinguished Member

    Aug 1, 2013
    4,515
    1,246
    No. In a simulation program a battery is considered to be a perfect voltage source, so the output would be V2 with or without the FET. When you run the sim what does it show?

    ak
     
  3. DickCappels

    Moderator

    Aug 21, 2008
    2,647
    632
    No, it creates a constant current source that only conducts when the instantaneous voltage from the AC voltage source is sufficiently high enough compared to the battery voltage to allow the JFET to generate enough current to cause the JFET to pinch off. Just noticed that your AC source is only 1V, there are few JFETs that will pinch off at such a low voltage.
     
  4. coinmaster

    Thread Starter Member

    Dec 24, 2015
    350
    6
    Whoops I was reading the wrong terminal by accident.
    How bout this?

    Screenshot_7.png

    Seems to work except I don't know where I'm going to get a p-jfet that can handle -80v. SIC versions are only n-type.
     
    Last edited: Mar 1, 2016
  5. coinmaster

    Thread Starter Member

    Dec 24, 2015
    350
    6
    There must be a way to buffer via Njfets......
     
Loading...