This circuit is from a National Semiconductor manual from the 1980s. The integrated circuit is rare today and next to the diagram we have the formula for calculating the components.
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...