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 3 and-a-half digit circuit was found in a Teledyne documentation from the 90s. The circuit uses...
We found this circuit in an English publication in 1976. The circuit is based on the use of a...
This filter of two transistors has the cutoff frequency determined by the formulas next to the...