This circuit is from a 1968 Electronic Design. The circuit uses transistors of the time that can be replaced with modern equivalents. More stages can be used to get higher tension.
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...