Help with Gyrator circuit equivalence | opamp vs bjt

Started by Carlos Best, January 13, 2015, 07:22:11 PM

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thehallofshields

Quote from: Rob Strand on January 01, 2018, 11:52:27 PM
If you are using variable R1 going upto 1MEG then that's going to create more problems.  Probably won't work well even with the high gain normal transistor.  To be honest, with variable R1 replacing the opamps with a BJT probably isn't a good idea.  It isn't possible to tweak the circuit to the extent it needs to work well with R1 at 1MEG.

Understood. You just saved me dozens of hours of frustration.

I wish I had a use for a 4th OpAmp. A Voltage Follower for the Bias current or a Buffer at the end is all I can think up.