The circuit presented is based on the National Semiconductor's LM3524, a component not common today. The circuit is from the 1994 Linear Applications Handbook.
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...