The integrated circuit used is uncommon today. We found this configuration in Motorola's 1990 Linear Databook. The triac can be any of the TIC series.
In the figure we have a simple signal tracer circuit to be coupled to the volume control of an AM...
This circuit was found in documentation from the 90s, using components from that time. The...
This circuit, obtained from old documentation, allows the recovery of sulfated batteries. The...