Found in an American circuit manual from the 1970s, this circuit can use any general-purpose transistor. The operating frequency range is from 600 to 4000 Hz.
Found in English documentation, this circuit uses a thermistor as a sensor. The trigger point is...
The circuit is from the 1990 Motorola Linear Databook. Equivalent operations can be used and what...
We find this circuit in an old documentation, but it can be made using modern transistors. The circuit...