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.
This circuit was found in an American 1980s documentation. The components are current but most...
This simple timer for incandescent lamps or other non-electronic charges uses a triac as a control...
Found in a Radio Electronics store from the 90s, this circuit acts on the alternator. The circuit...