This is the basic configuration of an operational amplifier sample & hold circuit. The FET and transistor are commonly used. The circuit is from an 80's documentation.
Found in 90's Electronic Engineering, this circuit produces a pulse with a delay that depends on R3...
This circuit was found in the December 1984 issue of Radio Electronics magazine. The circuit has a...
Found in 90s Radio Electronics, this circuit is intended for amplifying analog video signals....