This is one of the channels of an amplifier suggested by Westinghouse in 1970s documentation. The circuit uses components from the era and no information about the transformer is given.
The presented circuit was suggested by the 1994 Linear Applications Handbook from National...
The use of a diac improves the performance of the two dimmers in the previous circuits. The...
This circuit was found in Radio Electronics from the 90s. It converts capacitance into frequency...