This circuit is from the National Semiconductor's Linear Applications Handbook of 1994. The circuit can be implemented with equivalent operational. The detected voltage is given by the diode.
This switching circuit for contact breaker cars was found in a Radio Electronics from April 1964....
This circuit was found in documentation translated from the 1960s. The circuit can be implemented with...
This 1987 signal injector included the power supply from the power grid. The transformer is 6 + 6...