This circuit uses an optical coupler called Raystor created by Raytheon in the 1960s. The circuit uses components from the era that can be changed. The current is low.
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...