This circuit was found in a Signetics documentation from the 1980s. Next to the figure are the waveforms of the generated signals. The transistor admits equivalent.
This circuit uses a resonant reed relay to recognize the frequency of an input signal. Adaptations...
The operational used is uncommon today, but equivalents can be used. Unlike the previous one, this...
This simple circuit uses a zener diode and two LEDs to indicate whether the voltage of a power grid...