This circuit is used in magnetic tape recorders, having been found in documentation in the 1960s. The circuit uses Japanese transistors, and the critical components are transformers.
This circuit was found in a Radio Electronics Constructor, English magazine from April 1976; The...
This circuit was taken from Maxim documentation from the 90s. The components are from the period....
This circuit was found in an Electronics World of 1968. It can be applied to any modern triac and...