We found this precision circuit in a manual from the 80's. The operational amplifier is of a common type at the time, and equivalents can be tested. Transistors are general purpose types.
The existence of field effect transistors at the input of the integrated circuit (operational...
This circuit using current components was found in an old documentation. It is a sequential circuit...
In the figure we have a signal detector using a tunnel diode. The circuit is from a Radio...