This circuit was found in a 90s Popular Electronics. With it, using a 4066, it is possible to control between 1 to 100 the gain of an operational amplifier like the 741.
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...