This negative voltage source was found in a Popular Electronics from the 90's. The transformer has 120V secondary and 4-12V primary.
This simple MAT generator circuit was found in a 1986 documentation. The Q2 transistor can be...
This circuit was found in an Electronics Now of the 90s. It is intended for amplifying composite...
This circuit was found in the 2005 Linear Technology Linear Circuit Manual. It is a sensor with large...