This is a circuit suggested by Linear Technology in a 1980s documentation. The integrated circuit is from the era. Observe the input and output voltage.
The integrated circuit used in this filter is not very common today, but the configuration can be implemented...
In fact, this is the circuit also known as “vox”, that is, a relay triggered by sound. This...
This circuit makes it possible to reverse the direction of a DC motor through a relay controlled by a...