This circuit was obtained in a 1970 engineering documentation. The operational is the 741, but other operational ones can be used. The power supply must be symmetrical.
The circuit shown in the figure can be used as an indicator of presence and high voltage in a...
This circuit uses the 2N626, the first commercial Darlington transistor. We found it in Radio...
This circuit can generate signals from 80 to 800 Hz with an amplitude of 0.3 V. We find it in a...