The ZN416E integrated circuit is uncommon today. It consists of a complete radio, like the one found in a 90s Popular Electronics. The power is from a single battery.
This circuit, from a publication from the 1970s, can be implemented with more modern transistors and 6 or...
This circuit switches off a load in case of excess current acting as a fuse. The circuit is from a...
This circuit was obtained from a manual of the integrated circuit itself, but can be applied to...