This UPS circuit was published in the March 1985 issue of Radio Electronics magazine. The components used are still common, although some may be difficult to obtain.
This line protector circuit was found in a 2002 documentation, but it is totally current and...
This antenna for the frequencies 146 or 440 MHz was found in a magazine 73 for Amateur Radio of...
With this circuit it is possible to increase the output voltage of a 7812 regulator. The circuit...