This circuit is from an old documentation from the 80's. The circuit provides an output signal for a warning or alarm system that indicates when a fuse or circuit breaker opens.
This is the basic configuration of many LM339 manuals, as a comparator with hysteresis. The font...
We found this circuit in a Popular Electronics of the 80's. The circuit can be used to drive...
This simple power supply for transistors was found in documentation from the 1940s. The...