This is a 1960s amplifier setup found in a period publication. The circuit uses a special driver transformer that inverts the phases of the signal to excite the output transistors.
This configuration, found in many publications, is from an American book from 1981. The power...
The circuit shown is from an American publication from 1970. It produces a tone that attracts fish...
Found a documentation on PCs from 1996, this circuit can be used as a shield. The relay is rated at...