Found in a 90s Elektor, this circuit is based on a Maxim integrated circuit of the time. The circuit supplies 5 V at its output with a maximum current of 50 mA.
This configuration that appears several times with variations on this site is from old American...
This configuration (somewhat critical, as the imbalance of characteristics between transformers can cause...
This circuit is from a Popular Electronics of the 90's. Any power MOSFET can be used. The circuit...