The sensors in this circuit that triggers when the temperature goes out of a certain range are common diodes. The circuit is from the 1991 Reista Electronics Experimenter's Handbook.
This shield circuit can serve as a basis for a digital mixer or simply for a switch without noise...
This shield or interface makes it possible to control power loads connected to the power grid from...
Based on an LM36000 OTA this circuit was found in the July 1988 issue of Radio Electronics...